1Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table of ContentsIntroduction ....................................................... 2Energy .............................................................. 3Protein and Amino Acids ................................... 7Minerals ........................................................... 14Vitamins .......................................................... 18Water .............................................................. 22Feed Processing ............................................. 23Feed Composition Table ................................. 31

General NutritionPrinciples for Swine

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IntroductionEfficient and profitable swine production

depends upon an understanding of the conceptsof genetics, environment, herd health, manage-ment and nutrition. These factors interact witheach other, and their net output determines thelevel of production and profitability. Feed repre-sents 60 to 75 percent of the total cost of porkproduction. Therefore, amino acids, carbohy-drates, vitamins, minerals, and water must beprovided and balanced to meet the pig’s require-ments. Thus, a thorough knowledge of the prin-ciples of swine nutrition is essential in order tomaintain a profitable swine enterprise.

Improvements in production have led tochanges in nutrient recommendations in order tomaximize performance. These requirements arecontinuously changing and this publication hasbeen divided into six sections so it can be revisedperiodically to keep up with the latest develop-ments and changes in technology. Furthermore,research summaries and additional informationmay be found by accessing our internet site atwww.oznet.ksu.edu/dp_ansi/welcome.htm. Thepurpose of these publications is to provide thelatest recommended nutrient allowances andanswer some of the more frequently askedquestions concerning swine nutrition. In someinstances it may be advisable to seek profes-sional nutrition advice for additional information.Suggestions made in this guide may not be appli-cable to swine production in other regions of theUnited States or in other countries.

Why is there variation in nutrientrecommendations among universities?

There is some variation among the landgrant universities in nutrient level recommenda-tions. The main reason for the differences is theamount of added nutrients beyond the NationalResearch Council (NRC) minimum requirement.The NRC periodically reviews and publishes esti-mates of the nutritional requirements for swine.These requirements are based on pigs fed underexperimental conditions with normal health andperformance. Many of the requirements arebased on feeding a corn-soybean meal diet. Inthis publication, the nutrient recommendationshave been increased beyond the NRC levels toadd a margin of safety for each of the essentialnutrients. In addition, with improved record keep-ing programs, there are data to suggest that feedintake in swine production systems may not beas great as previously estimated. Although a pig’srequirement for a specific nutrient may be thesame, if it is not eating the estimated amount, thenutrient density of the diet must be increased inorder to meet its daily nutrient requirement. Our

purpose is to reduce the risk of nutrient deficien-cies that might occur because of differences iningredient quality, genetics, health, environment,and performance on individual farms, and providea margin of safety in a cost effective manner.

What are some of the factors thatinfluence nutrient requirements?

Several factors affect a pig’s requirement fora specific nutrient. Requirements are influencedby a combination of growth potential and feedintake, which will require changing the concentra-tion of the nutrient in the diet to meet the pig’srequirement on an amount-per-day basis. Someof these factors are:• Environment (temperature, weather, housing

and competition for feed)• Breed, sex, and genetic background of pigs• Health status of the herd• Presence of molds, toxins, or inhibitors in the

diet• Availability and absorption of dietary nutrients• Variability of nutrient content and availability in

the feed• Level of feed additives or growth promotants• Energy concentration of the diet• Level of feeding, such as limit feeding versus

ad libitumEnvironmental temperatures and housing

conditions play an important role in determiningthe pig’s nutrient needs for maintenance. Pigshoused in outside dirt lots are exposed to greatertemperature changes than those housed in con-finement facilities and may have greater mainte-nance needs. In addition, research has indicatedthat pigs of different sex, breeds, or genetic back-ground may have different capacities for produc-tion, thus different nutrient requirements. It isreasonable to expect that a sow weaning 27 pigsper year would have a higher requirement thanone weaning only 15 pigs per year. Feed quality,including processing methods; nutrient availabilityand variability; and the presence of molds, toxins,or anti-nutritional factors will influence pig perfor-mance and feed costs. Herd health status andthe presence and level of feed additives or growthpromotants will also alter nutrient utilization.Finally, factors affecting feed intake such as levelof feeding or energy density of the diet will alterrequirements. In general, as measures are takento increase production (i.e., growth rate or pigsper sow per year, etc.), increasing the nutrientfortification of the diet may be required to meetthese challenges in pig production. Tables 1 and2 list typical growth rates, carcass traits, and sowperformance, as well as goals for future produc-tion values. As an industry, we need to be awareof our past as well as keep an eye on the future inorder to remain competitive and profitable.

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EnergyCarbohydrates and fats in the diet supply

most of the pig’s caloric needs. Today, energyrequirements are expressed as kilocalories (kcal)of digestible (DE), metabolizable energy (ME), ornet energy (NE) per pound of feed. Digestibleenergy is defined as the amount of energy in thefeed minus the amount of energy lost in the feces,whereas ME is defined as the amount of energyin the feed minus the energy lost in the feces andurine. Net energy is defined as the amount ofenergy in the feed minus the energy lost in feces,urine, and the heat produced through digestiveand metabolic processes (heat increment).Digestible and metabolizable energy are themost frequently used terms to describe energyvalues for swine; however, as more data becomesavailable on the heat increment of feed ingredi-ents for swine, NE may become a more precisemethod to evaluate energy needs of swine.

Energy sources for swine are the cerealgrains: corn, milo, wheat, barley, and theirby-products. In addition, fat, which contains2.25 times the amount of energy as cereal grains,is often used to increase the energy density ofswine diets. Most common cereal grains andfats are quite palatable and digestible. However,cereal by-products tend to be more variable;therefore, their use in swine diets may be limited.

Although cereal grains will provide carbohydratesto meet the pig’s energy needs, they must besupplemented with amino acids (protein), vita-mins, and minerals to meet the pig’s requirementsfor these nutrients. In the past, when formulatingdiets with the common cereal grains we werenot as concerned with energy concentrationsbecause the pig will often eat to meet its energyrequirement. However, to make accurate deci-sions on the potential use of alternative energysources, it is becoming more important to knowdietary energy concentrations to evaluate pos-sible changes in feed efficiency. Furthermore,when low-energy feeds are used, pigs are limit-fed (sows and gilts), or external factors limit feedintake, dietary energy levels must be determinedto ensure adequate intake.

Are corn and milo (sorghum) comparable?Both grains are excellent energy sources in

swine diets. In Kansas, however, milo is often acheaper source of energy and produces moreeconomical gains. Because the energy contentof corn is slightly higher than that of milo, feedefficiency of pigs fed corn diets will be slightlybetter than that of pigs fed milo, but averagedaily gains will be the same. A general recom-mendation for swine diets is to replace corn withmilo on a pound-for-pound basis or on a lysinebasis. One disadvantage of milo is that it can be

Table 1. Pig Performance Standards a.

Percentile

50th 90th

Nursery PerformanceADG, lb .85 1.03ADFI, lb 1.42 1.85F/G 1.71 1.44

Grow-finish performanceADG, lb 1.61 1.80ADFI, lb 5.05 5.85F/G 3.15 2.80

a 1995 Pig Champ Database Summary.

Table 2. Average Overall Herd Performance a.

Percentile

50th 90th

Avg nonproductive days 70.5 45.4Farrowing rate 80.1 88.9Avg pigs born live 10.2 11.0Litters/female/year 2.09 2.34Pigs weaned/litter 9.0 9.8Adjusted 21-day litter, wt, lb 125.2 142.5Pigs weaned/female/year 18.6 21.8a 1995 Pig Champ Database Summary.

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more variable in nutrient content than cornbecause of growing conditions. In addition,because a milo kernel is smaller and harderthan a corn kernel, fine grinding (1⁄8- or 5⁄32-inchscreen) or rolling is suggested for best utilization.

What other energy feeds can be fed to pigs?Wheat. Wheat is an excellent feed grain for

swine, but usually is not competitively priced withmilo or corn. Wheat can replace all or part of thecorn or milo in a swine diet without affecting per-formance. Because wheat has slightly more lysineand phosphorus than corn and milo, the amountof soybean meal and supplemental phosphoruscan be reduced in the diet. Research has shownthat soft red winter wheat is comparable in feed-ing value to hard red winter wheat for finishingpigs. Because wheat tends to flour when pro-cessed, it should be coarsely ground (3⁄16-inchscreen) or rolled. If ground too finely, feed intakemay be decreased and performance lowered.

Barley. Barley also contains more lysine thanmilo or corn. However, it contains less energy andmore fiber. Therefore, pigs fed barley-based dietswill tend to have 5 to 10 percent poorer feed effi-ciency. Fine grinding (600 to 700 microns) of bar-ley diets improves the feeding value for growing/finishing pigs, but when energy intake is critical,barley diets are not recommended.

Oats. Oats also have more lysine than eithermilo or corn, but again their high fiber contentlimits their application in swine diets. Oats shouldnot exceed 30 percent of the diet for growing/finishing pigs. Because of the high fiber contentof oats and barley, they may be best utilized insow gestation diets, if economically priced.

High-lysine corn. Opaque-2 corn, com-monly called high-lysine corn, is a variety of cornthat has been selected for improved protein qual-ity. High-lysine corn is higher than regular corn inall essential amino acids except leucine. Becausethe lysine content is higher than that of normalcorn (.38 versus .25 percent), diets should beformulated on a lysine basis. The major disadvan-tages of high-lysine corn are reduced yields anddecreased kernel durability.

Genetically Engineered Grains. Advancesin genetic engineering have resulted in the devel-opment of several cultivars of different grains withadded nutritional value. Currently, high-oil corn isone of the more widely available engineeredgrains for use in swine diets. As the name implies,high-oil corn typically contains more oil (6.5 ver-sus 3.5 percent) than conventional corn whichprovides approximately 70 kcal/pounds moreenergy. Furthermore, high-oil corn has beenshown to have more lysine than conventionalcorn (.30 versus .26 percent) which can reducethe amount of soybean meal needed in the diet.

As a result, a typical finishing diet with high-oilcorn would provide approximately 50 pounds ofadded fat and replace 20 pounds of soybeanmeal. Recent research suggests that the nutrientsin high-oil corn are equally available as in conven-tional corn. Therefore, under typical pricing situa-tions, high-oil corn is worth approximately $.20 to.25/bushel more than conventional corn. Thispremium will change based on changes in fat,corn and soybean meal prices. With time, newvarieties of engineered grains with other improvedquality traits will become available. These grainswill need to be evaluated as they are introduced.In addition, there will be a need for greateremphasis on quality control and analytical pro-cedures to verify nutrient composition.

The amount of feed per unit of gain is notthe most important factor in formulating swinediets. Cost per unit of gain is more important;therefore, it is necessary to use the most eco-nomical energy sources in swine diets. The rela-tive feeding values listed in Table 3 can be usedto calculate the most economical energy source.For example, if corn costs 5.0 cents per pound,milo is a better value when it costs less than4.8 (5.0 × 96 percent) cents per pound.

What feed ingredients should befed in limited amounts?

There is no perfect feed ingredient that canbe fed to pigs by itself. Some feeds, if added tothe diets in excess amounts, will decrease perfor-mance. Some less commonly fed feedstuffs, suchand millet and rye, should not exceed the recom-mended levels shown on Table 4.

Should fat be added to swine diets?Fats and oils such as choice white grease,

beef tallow, corn oil, and soybean oil contain about2.25 times as much metabolizable energy as mostof the cereal grains. Research indicates that theaddition of 3 to 5 percent fat to growing–finishingswine diets will improve feed conversion and oftenaverage daily gain. However, adding fat to ad libi-tum fed diets generally tends to increase backfatthickness. A reduction in the amount of dust willbe evident and wear on mixing equipment andaugers will be reduced with 2 to 3 percent addedfat. Addition of fat above 5 percent will furtherimprove feed conversion, but physical handlingproblems such as bridging in the feeders and cak-ing in the mixer may limit the use of these higherlevels. Diets containing fat may become rancidduring prolonged storage or when feed is exposedto high temperatures. Therefore, an antioxidantsuch as ethoxyquin, BHT, or BHA may need to beadded to fat before mixing it into the rations.

Adding fat to swine diets is a matter ofeconomics. Fat additions will usually increasethe cost of the diet, which must be offset by an

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Table 3. Feeding Value of Energy Feeds Compared to Corn.

Feedstuff Relative value compared to corn, %

Corn 100Alfalfa meal, dehydrated 65 to 75Barley 90 to 95High lysine corn 110 to 115Millet 90 to 95Milo 96Oats 70 to 80Oat groats 110 to 115Rye 80 to 85Fat and oil 210 to 220Triticale 95 to 105Wheat 105 to 107Wheat middlings 90 to 95Whey, dried 100 to 110

Table 4. Typical Maximum Usage Rates for Common Energy Sources a.

Maximum recommended percent of complete dietb

Ingredient Starter Grow-finish Gestation Lactation Limitation

Alfalfa meal, dehy 0 10 25 0 High fiberBakery waste, dehy 25 * * * High saltBarley 25 * * 25 High fiberBeet pulp 0 5 50 0 High fiberCorn * * * * NoneCorn distillers grains 5 15 40 5 Amino acid balance w/solubles, dehyCorn gluten feed 5 10 * 5 High fiberCorn, hominy feed 0 60 60 60 Amino acid balanceFat/oils 8 5 5 5 Feed handlingMillet 10 40 40 10 Difficult processingMolasses 0 5 10 5 Low energyOats 5 20 50 0 High fiberOats groats * * * * NoneRyec 0 25 25 10 VariabilitySorghum (milo) * * * * NoneTriticalec 10 * * 50 VariabilityWheat bran 0 10 30 10 High fiberWheat, hard * * * * NoneWheat middlings 5 25 * 5 High fiberWheat shorts 10 40 40 40 VariabilityWhey, dried 40 15 5 5 High lactosea Adapted from the NPPC Feed Purchasing Manual, Nebraska and South Dakota Swine Nutrition Guide,

and Swine Nutrition Guide from the Prairie Swine Centre.b Percentages suggest maximum allowable inclusion rates for energy sources. Economics and pig

performance standards must be considered for actual inclusion rates. Most or all of the nutritionallimitations can be overcome with proper formulation.

c Must be free of ergot.* Denotes no nutritional limitation in a diet balanced for essential amino acids, energy, minerals, and

vitamins.

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increase in pig performance. Several commercialsupplements and complete feeds contain addedfat. New commercial products that contain driedfat may reduce part of the mechanical problemsof adding liquid fat on the farm, but the economicfeasibility of using these products must be evalu-ated. Fat products that have limestone as thecarrier should be avoided, because the calciumwill decrease the digestibility of the fat.

Research with sows suggests that feedinga diet with 5 percent added fat at a rate of5 pounds/day for 10 days before farrowing hasthe potential to improve pig survivability ifpreweaning survival is below 80 percent. Thereasons for the increase in survival rate appearto be increases in milk yield and milk fat content.

The potential benefits of fat addition must beevaluated in terms of economic considerations.When calculating what price you can pay for add-ing fat to a swine diet, the following equation canbe used:

For example, if adding fat will increase dietcost by 5 percent, you must get at least a 5 per-cent improvement in feed efficiency before it iseconomical. It is important to note that this equa-tion does not take into account changes in carcasscharacteristics or average daily gain. Fat may beadded in summer diets to increase the energydensity of the feed to offset low feed intake due tohigh temperatures. Feed efficiency is usuallyimproved 2 percent for each 1 percent incrementof added fat in growing–finishing pig diets.

Are there differences in fat sources?Recent research has shown that not all fat

sources give similar improvements in pig perfor-mance, especially for baby pigs. This may be aresult of the fat source’s fatty acid profile or impu-rities from the rendering process. In general, fatsources such as soybean oil and choice whitegrease are considered higher quality than tallowand yellow grease. Evidence indicates that blendsof soybean oil and coconut oil support excellentperformance in baby pigs. Waste cooking oilsmay be utilized in swine diets but should also bechecked for quality. Cooking oils often containhigh levels of free fatty acids which impair feedintake and increase corrosion of equipment. Fatsources of questionable quality should be ana-lyzed for moisture, impurities, and unsaponafiablematerial (MIU), as well as total and free fattyacids. Moisture should not exceed 1 percent,impurities .5 percent, unsaponifiable material1 percent, and total MIU 2.5 percent. Total fattyacids should be at least 90 percent while free

fatty acids should be no greater than 15 percent.In addition, initial peroxide value provides an indi-cation of rancidity potential. The peroxide valueshould be below 5 meq.

What is the feeding value of low testweight or weather damaged grains?

Under adverse weather conditions, such asdrought, floods, and early frosts, low test weight,or sprout-damaged grain may be available for usein swine diets. As the degree of sprout damageincreases or test weight decreases, the energycontent of the grain is decreased. Therefore, thepig will need to eat more feed to meet its energyrequirement. Although average daily gain will usu-ally not be affected, feed efficiency will becomepoorer. Research has shown that this occurs whenmilo drops below 45 pounds per bushel test weightand wheat is below 50 pounds test weight. Further-more, milo with up to 40 percent sprout damagecan be effectively utilized by growing–finishing pigs.When the test weight of milo and wheat drop below45 and 50 pounds, respectively, or there is morethan 40 percent sprout damage, average daily gainwill begin to be affected. Blending low test weightor sprout-damaged grain (up to 50 percent) withnormal grain is an effective way to utilize weather-damaged grain. It is extremely important torecalibrate volumetric mixing equipment whenfeeding low test weight grains. Probably the biggestdisadvantage to weather damaged grain is theincreased potential for mold or aflatoxin contamina-tion because of high moisture content. Therefore,weather damaged grains should always bescreened for molds and aflatoxin and, if contami-nated, these grains should not be fed to starterpigs or the breeding herd. If contaminated grainsare going to be used, they should be blended withnormal grain and only fed to growing-finishing pigsin limited amounts. Several compounds such asbentonite clay and alumniosilicates have beenshown to improve pig performance when mold-contaminated grains are fed.

What are mycotoxins?Mycotoxins are compounds produced by

molds that when consumed by animals orhumans will cause a toxicity. Not all molds pro-duce mycotoxins and molds that do producemycotoxins may only produce them under certainconditions. The type of clinical signs and thedegree of toxicity exhibited by animals consumingmycotoxin contaminated grain will depend on thetype and amount of mycotoxin in the feed grainand the class and species of animal. A listing ofsome of the more common mycotoxins and theirclinical effects on swine is listed in Table 5. Ingeneral, young animals and breeding animals aremore susceptible to the effects of mycotoxins.Although molds can produce many different

New Cost – Old Cost × 100 < % improvement inNew Cost efficiency needed to offset

added diet costs

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mycotoxins, the two most commonly detectedmycotoxins in wheat, milo, and corn in the Mid-west are vomitoxin and zearalenone.

What is vomitoxin and what effectdoes it have on swine?

As the name of the toxin implies, vomitoxincan cause vomiting in pigs if consumed in largeenough quantities. However, the most commonsigns in pigs consuming vomitoxin-contaminatedfeeds are feed refusal and decreased feedefficiency. The feed refusal results in reducedaverage daily gain. Vomitoxin adversely affectsthe function of many of the major organs of thebody such as the liver and brain. This results indecreased nutrient utilization and feed efficiency.Thus, vomitoxin has the greatest detriment toperformance in young, rapidly growing nurseryage pigs. Vomitoxin has also been reported tocause reproductive problems in sows.

What is zearalenone and what effectdoes it have on swine?

Zearalenone is a compound that mimics theeffects of the hormone estrogen. Thus, most of theeffects of zearalenone are confined to the repro-ductive tract of swine. Gilts and sows consumingzearalenone-contaminated grain will exhibit vulvarreddening and swelling. Vaginal and rectalprolapses are a frequent result of zearalenoneconsumption in swine. They also will exhibit fre-quent, irregular estrous cycles and litter size maybe drastically decreased. Young boars will undergoa feminizing effect, with atrophy of the testes andenlargement of the mammary gland. Researchhas indicated that normal reproductive functionresumes after the removal of zearalenone-contaminated grain from the diet. There is littleevidence to indicate negative effects on growthperformance in growing and finishing swine.

Can mycotoxins be a problem ingrain by-products?

Yes, many times grain by-products containthe hulls or the outer covering of the grain wheremycotoxin concentration is greatest. Mycotoxinconcentrations may actually be higher than in theoriginal lot of grain. For example, wheat middsconsist of the parts of the wheat kernel wheremost of the mycotoxins are attached. The produc-tion of wheat midds actually concentrates thelevel of mycotoxins. Careful consideration andtesting for mycotoxins should be undertakenwhen grain by-products are included in swinediets. Other possible problems could arise fromthe use of mycotoxin contaminated straw for ges-tating sows. Gestating sows on limit fed diets mayconsume large quantities of contaminated strawresulting in a toxicity. Mycotoxin contaminatedstraw should not be a problem for finishing pigswith access to clean feed.

What steps should be taken if mycotoxincontaminated grain is suspected?

The first step is to obtain a 1- to 2-poundrepresentative sample of grain and have it ana-lyzed for the presence of mycotoxins. The sampleshould be transported to the laboratory in a papersack. The paper sack prevents the condensationof moisture and the further proliferation of moldgrowth. An excellent laboratory for the detectionof mycotoxins is the Veterinary Diagnostic Labora-tory at North Dakota State University (Table 12).Several other state and private laboratories alsotest for the presence of mycotoxins.

What are some recommended guidelines forfeeding mycotoxin-infected grains?

The optimum solution is to buy clean grainfor swine and feed the contaminated grain tocattle. Feeder cattle should be able to safelyconsume levels five to 10 times higher than swine.If contaminated grain must be fed, the followingtable lists some maximum recommended levelsin swine diets for various mycotoxins (Table 5).

Protein and Amino AcidsThe pig does not have a specific requirement

for crude protein, but rather for the individual com-ponents or sub-units that make up protein, calledamino acids. Proteins are made up of several differ-ent combinations of approximately 20 differentamino acids. During the process of digestion, pro-teins are broken down into individual amino acidsthat are absorbed into the bloodstream. The aminoacids are then incorporated into new protein mol-ecules. When formulating diets with commonlyavailable grains and protein sources, the level ofcrude protein typically used to describe the dietusually will contain adequate amounts of aminoacids to meet the pig’s requirement. However, it isimportant to remember that this is not always truewhen using synthetic amino acids and alternativeor by-product feed ingredients, and that the dietarylevels of amino acids should always be checked. Itis becoming increasingly important to specify lysinelevels when formulating and evaluating swine diets.

If a diet is inadequate in any essential aminoacid, protein synthesis cannot proceed beyondthe rate at which that amino acid is available. Thisis called a limiting amino acid. Another way ofdescribing a limiting amino acid is thinking ofprotein as a rain barrel and the amino acids asthe individual staves making up the barrel. If onestave (amino acid) is shorter than the others (lim-iting), the barrel can only be filled to the level ofthe shortest stave. In the pig, a deficiency of oneor more amino acids will result in depressedgrowth rate, poor feed conversion, unthriftiness,or reduced reproductive performance. Therefore,protein quality can be defined as how closely the

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Table 5. Clinical Guide to Mycotoxins in Swine a.

Toxin Category of swine Dietary levelb Clinical effects

Aflatoxins Growing/finishing <100 ppb No clinical effect; residues in liver200–400 ppb Reduced growth and feed efficiency;

possible immuno-suppression400–800 ppb Microscopic liver lesions, cholangio-

hepatitis; increase serum liver enzymes; immuno-suppression

800–1200 ppb Reduced growth; decreased feed consumption; rough hair coat; icterus; hypoproteinemia

1200–2000 ppb Icterus; coagulopathy; depression; anorexia; some deaths

>2000 ppb Acute hepatosis and coagulopathy; deaths in 3–10 days

Brood sows/gilts 500–750 ppb No effect on conception; deliver normal piglets that grow slowly due to aflatoxin in milk

Ochratoxin Finishing 200 ppb Milk renal lesions seen at slaughter; and citrinin reduced weight gain

1000 ppb Polydipsia; reduced growth; azotemia and glycosuria

4000 ppb Polyuria and polydipsiaSows/gilts 3–9 ppm Normal pregnancy when fed first month

Trichothecenes Growing/finishing T-2 toxin and DAS 1 ppm No effect

3 ppm Decreased feed consumption10 ppm Decreased feed consumption; oral/

dermal irritation; immuno-suppression20 ppm Complete refusal, vomiting

Deoxynivalenol (vomitoxin) 1 ppm No clinical effect, minimal reduction in

feed consumption5–10 ppm 25–50% reduction in feed consumption20 ppm Complete refusal

Zearalenone F-2 toxin Prepuberal gilts 1–3 ppm Estrogenic; vulvovaginitis, prolapse

Cycling sows/gilts 3–10 ppm Retained corpora lutea, anestrus, pseudopregnancy

Pregnant sows >30 ppm Early embryonic death when fed 1–3 weeks postmating

Ergot All swine .1%c Reduced gainSows, last trimester .3% Reduced piglet birth weight; agalactiaAll swine .3% GangreneAll swine 3.0% Decreased feed consumption

Fumonisins All swine 50–100 ppm Acute pulmonary edema; hepatosis; (estimated) impaired lymphoblastogenesis;

decreased feed consumptiona Adapted from Mycotoxins, by G. D. Osweller in Diseases of Swine, 7th Ed.b Estimated toxic concentrations are based on literature values.c Concentration of ergot sclerotia in diet.

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essential amino acids in the protein source cometo meeting the pig’s estimated requirement forthose amino acids. The 10 essential amino acidsthat must be provided in swine diets are: lysine,threonine, tryptophan, methionine (and cystine),isoleucine, histidine, valine, arginine, and pheny-lalanine (and tyrosine). Most cereal grains arelimiting in lysine, tryptophan, threonine, andmethionine. Therefore, when evaluating feedingredients, these amino acids, especially lysine,are most important in determining protein quality.

What are some other commonsources of amino acids?

Protein sources are classified into two majorcategories: animal (tankage, meat and bonemeal, fish meal, or spray-dried blood meal) andplant (soybean meal, cotton seed meal, or corngluten meal). Soybean meal is usually the mosteconomical source of high quality protein avail-able to Kansas swine producers. It is the onlyplant protein that compares with animal proteinin terms of quality of amino acid content and ratioand can be used as the only protein source inmost swine diets. Therefore, there is no need tohave both animal and plant protein sources in aswine diet, with the exception of starter diets,which should contain dried whey and (or) spray-

dried blood products. Producers in Kansas andother states may have the choice of buying either44 percent or 46.5 percent crude protein soybeanmeal. The primary difference is that 44 percentsoybean meal is made by adding soy hulls to46.5 percent soybean meal. In addition to thelower fiber content, transportation costs may favorbuying the 46.5 percent soybean meal.

How can I determine the mosteconomical protein source to use?

In order to determine the relative feedingvalue of alternative protein sources, it is importantto compare the lysine level in the new proteinsource to soybean meal. The relative feedingvalues of some alternative protein sources arelisted in Table 6. This can be utilized to determinethe comparative economic value of the proteinsource as a partial or complete replacement to44 percent soybean meal. These feeding valueswere calculated by dividing the lysine content ofthe feed ingredient by that of 44 percent soybeanmeal (2.85 percent lysine) and multiplying by100 to put them on a percentage basis.

Assuming that 44 percent soybean meal canbe purchased at $250 per ton, what would a tonof 46.5 percent soybean meal be worth? Becausethe lysine content of 46.5 percent soybean meal

Table 6. Alternative Amino Acid Sources.

Source Protein % Lysine % Relative value as a lysine source, %

Plant proteinsSoybean meal 44 2.85 100Soybean meal 46.5 3.01 106Soy protein concentrate 66 4.2 147Soy protein isolate 92 5.2 182Alfalfa meal 17 .80 28Canola meal 38 2.27 80Corn gluten meal 42.1 .78 27Sunflower meal 45.5 1.68 60Cottonseed meal 41 1.51 53Potato protein 76 6.27 220Wheat bran 15 .56 20Wheat gluten, spray-dried 74 1.3 46Wheat middlings 16 .68 24Yeast, brewers dried 45 3.23 113

Animal proteinsAnimal plasma, spray-dried 70 6.5 228Egg protein, spray-dried 48 3.3 116Fish meal 60 4.75 167Blood meal, spray-dried 86 8.02 281Fish solubles, dried 54 1.73 61Meat and bone meal 50 2.80 98Skim milk, dried 33 2.54 89Tankage 60 3.00 105Whey, dried 12 .97 34

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is 3.01 percent and 44 percent soybean meal has2.85 percent lysine, 46.5 percent soybean mealhas 106 percent the feeding value of 44 percentsoybean meal (3.01/2.85 × 100 = 106%). There-fore, if 106 percent is multiplied by the cost of44 percent soybean meal (106% × $250),46.5 percent soybean meal is of greater valuethan 44 percent soybean meal if it costs less than$265 per ton.

At what levels can feed ingredientsbe substituted for soybean meal?

When substituting other protein sources forsoybean meal, it is important to consider the maxi-mum level at which the new feed ingredient canreplace soybean meal without seriously affectingperformance. Table 7 is a list of alternative proteinsources that can be used in starter, growing–finishing, gestation, and lactation diets to replaceall or part of the soybean meal. By using this table,you can determine the maximum replacement rateof the feed ingredient for soybean meal.

Can other alternative proteinsources be fed to pigs?

This section lists some of the more commonsubstitutes for soybean meal in swine diets. Veryoften, these feed ingredients may appear to beeconomical compared to soybean meal. However,there are often many “hidden” costs or disadvan-tages in using these feed ingredients that are notreflected by their price. These include storagecosts, anti-nutritional factors, product variability,fiber content, spoilage, and under- or over-processing. These factors are especially problem-atic in “by-product” protein sources. Becauseby-product feed ingredients tend to vary more incomposition, proper information regarding chemi-cal composition is necessary to ensure optimumpig performance. Additional protein sources andrecommended maximum inclusion rates for eachstage of production are listed in Table 7.

Cottonseed MealCottonseed meal ranks second in produc-

tion compared to soybean meal. However, its usein swine diets is limited because of the deleteri-

Table 7. Typical Maximum Usage Rates for Common Amino Acid Sources a.

Maximum recommended percent of complete dietb

Ingredient Starter Grow-finish Gestation Lactation Limitation

Alfalfa meal, dehy 0 10 25 0 High fiberAnimal plasma, spray-dried * * * * NoneBlood meal, spray-dried 3 5 5 5 Low isoleucineCanola meal 0 15 15 15 Anti-nutrition factorCorn distillers grains 5 15 40 10 Amino acid balance w/solubles, dehyCorn gluten meal 10 30 * 10 Amino acid balanceCottonseed meal 0 10 15 0 Low lysineEgg protein, spray-dried 6 10 10 5 Anti-nutrition factorFish meal 20 6 6 6 “Fishy” porkMeat and bone meal 5 5 10 5 High mineralsMeat meal 0 5 10 5 High mineralsSkim milk, spray-dried * * * * NoneSoy protein concentrate * * * * NoneSoy protein isolate * * * * NoneSoybean meal * * * * NoneSoybean, full-fat, heat-treated * * * * OverheatingSunflower meal 0 20 * 0 Low energyTankage 5 5 5 5 QualityYeast, brewers dried 5 10 10 10 VariabilityWheat gluten, spray-dried 10 * * * Low lysineWhey, dried 40 15 5 5 High lactosea Adapted from the NPPC Feed Purchasing Manual, Nebraska and South Dakota Swine Nutrition Guide,

and Swine Nutrition Guide from the Prairie Swine Centre.b Percentages suggest maximum allowable inclusion rates for energy sources. Economics and pig

performance standards must be considered for actual inclusion rates. Most or all of the nutritionallimitations can be overcome with proper formulation.

* Denotes no nutritional limitation in a diet balanced for essential amino acids, energy, minerals andvitamins.

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ous effects produced by the residual free gossy-pol found in the pigment glands of the seed. Al-though fairly high in protein, cottonseed meal islow in lysine and tryptophan. It is recommendedthat cottonseed meal replace no more than50 percent of the soybean meal or protein supple-ment in the diet. At this inclusion rate, it is unlikelythat the total diet will contain over .01 percent freegossypol. Pig performance begins to be reducedat gossypol concentrations of .04 percent of thediet. Solvent extracted, gossypol-free cottonseedmeal can be used to replace 75 percent of theprotein source in growing–finishing diets whenbalanced on a lysine basis.

Canola MealCanola meal is the by-product of vegetable

oil processing from canola. Because it is welladapted to cool season growing conditions,canola is produced primarily in Canada and thenorthern states. Its oil contains a high level ofunsaturated fats, and production is expandingthroughout the United States. Canola meal aver-ages between 35 and 40 percent crude proteinand has less lysine but more sulfur-containingamino acids than soybean meal. Some older vari-eties of canola (rapeseed) contain high levels ofa toxic compound, glucosinolate, which effectsthyroid functioning. However, new cultivars of low-glucosinolate rapeseed (< 1 mg/g) have beendeveloped and are commonly referred to ascanola meal to distinguish it from the older vari-eties of high-glucosinolate rapeseed. It is notadvisable to feed meals from the cultivars of highglucosinolate rapeseed. Reduced palatability,high fiber, and low digestible energy have beencauses of slightly poorer performance of pigs feddiets containing canola meal. Canola meal canbe used to replace up to 50 percent of the proteinfrom soybean meal in growing-finishing and sowdiets without adversely affecting performance.

Sunflower MealSunflower meal is produced by extraction of

the oil from sunflower seeds. Because of its highfiber content (22 to 24 percent), it should be uti-lized in limited quantities in swine diets. Sunflowermeal is relatively low in lysine yet high in sulfur-containing amino acids in comparison to soybeanmeal. Sunflower meal containing high levels of oilwill produce soft pork because of the oil’s unsat-urated fatty acid content. It appears that sunflowermeal may replace up to 25 percent of the proteinin the diet for growing-finishing pigs.

Meat and Bone MealMeat packing by-products often are economi-

cally feasible to add to swine diets. In general, meatand bone meal is an excellent source of calcium

and phosphorus. However, it is often very low intryptophan and methionine. Since there is consider-able variation in the type and quality of the rawmaterials used, there is potential for greater varia-tion in the quality of meat and bone meal. Excessiveheating during the processing of meat and bonemeal may also decrease its digestibility and valueas a protein source. Therefore, it is recommendedthat meat and bone meal should not exceed25 percent of the protein supplement.

Spray-dried Blood ProductsSpray-dried blood products have revolution-

ized nutritional programs for early-weaned pigs.Spray-dried animal plasma and spray-dried bloodmeal, by-products of blood obtained from swineand cattle processing plants, are the most excit-ing protein sources to become available to theswine industry in recent years. Previously, spray-dried animal plasma has been used as a supple-ment for cereal protein in bakery products as wellas an emulsifying agent in meat products and petfoods. It is made up of the albumin, globin, andglobulin fractions of blood and contains 68 per-cent protein and 6.9 percent lysine. The blood iscollected in refrigerated tanks and prevented fromcoagulating by adding sodium phosphate. Theplasma fraction is separated from the blood cellsby centrifugation and stored at 25°F until theproduct is spray dried. This process consists ofpreheating (25 minutes at 200°F), spray-drying(1 to 2 minutes at 405°F), and evaporating ofmoisture (1 to 2 minutes at 200°F), resulting ina fine-grained powder. Spray-dried blood mealis processed similarly, except it contains theplasma and red blood cell fractions. Spray-driedred blood cells, a by-product of animal plasmaproduction, appears to have similar nutritionalvalue in starter diets as spray-dried blood meal.

When adding spray-dried blood productsto starter diets, dietary methionine levels mustbe checked because these ingredients are lowin methionine. Synthetic methionine should beadded to starter diets containing either spray-driedanimal plasma, blood meal, or red blood cells.

Spray-dried Wheat GlutenSpray-dried wheat gluten is the protein frac-

tion of wheat remaining after the starch has beenextracted for use in human food products. Wheatgluten contains approximately the same crudeprotein content as spray-dried animal plasma(75 versus 68 percent, respectively) but it isextremely low in lysine (1.3 percent). Aminoacid supplemented starter diets containing spray-dried wheat gluten provide similar growth perfor-mance as diets containing dried skim milk andmay be more cost effective.

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Soy Protein ConcentrateSoy protein concentrate contains approxi-

mately 65 to 70 percent protein and approximately4.2 percent lysine. It is produced by removing thewater soluble sugars, ash and other minor con-stituents from defatted soy flour by either an alco-hol, dilute acid, or warm water extraction. All threeof these systems are utilized in the feed industry,producing products similar in composition.Research results indicate that soy protein con-centrate can effectively replace dried skim milk instarter pig diets. Furthermore, research suggeststhat pigs fed moist extruded soy protein concen-trate may have greater average daily gain andbetter feed conversion than pigs fed soy proteinconcentrate.

Soy Protein IsolateThe highest concentrated soy protein source

is the soy isolate. To produce a soy isolate, defat-ted soy flakes are insolublized by reducing the pHto 4.5 (isoelectric point). At this point, the isoelec-tric proteins are separated from the soluble mate-rials. The process is similar to the acid extractionprocedure described to produce soy protein con-centrate. The removal of insoluble fibrous materialby either decantation or centrifugation completesthe protein isolation procedure. This final productcan be spray-dried to give an isoelectric protein,or neutralized to pH 7.0 and dried to give thecommon soy protein isolate. During protein isola-tion, protein yield is decreased due to minor pro-teins remaining soluble. Soy protein isolate is alsoan effective replacement for dried skim milk instarter pigs diets.

Raw SoybeansRaw soybeans, especially weather damaged

or low test-weight beans, are often attractivealternatives to add to swine diets. However, rawsoybeans contain high quantities of trypsin inhibi-tors, which block normal protein digestion in pigs.As the pig becomes older, its susceptibility totrypsin inhibitors decreases. Therefore, raw soy-beans may be used in gestation diets (but notlactation) without adversely affecting performance.If raw soybeans are to be used in diets for youngpigs, it is important to heat the beans to inactivatethe trypsin inhibitors. New varieties of soybeansare under development in which one of the trypsininhibitors (Kunitz inhibitor) have been geneticallyselected against, which would allow for greateruse in growing pig diets. However, research showsthat some heat treatment of low Kunitz inhibitorsoybeans is required for maximum utilization.

What is the value of full-fat soybeans?On-farm processing by roasting or extruding

of raw soybeans, if done properly, results inexcellent sources of protein. On-farm roasting or

extruding yield “full-fat” soybeans, which, in someinstances, are among the cheapest means ofadding fat to swine diets. Because of the eco-nomic relationship between soy oil and soybeanmeal and the cost of other fat sources and incor-porating them into your feed mill, it may be moreeconomical to utilize full-fat soybeans instead ofselling the beans and buying back soybean mealand oil. Because whole or full-fat soybeans haveless protein and lysine than soybean meal (32 to37 percent protein and 2.1 to 2.4 percent lysine),it is necessary to add 20 to 25 percent morewhole soybeans than soybean meal to have asimilar protein level in the diet. At the same time,this will supply approximately 3 percent addedfat to the diet, which will improve feed efficiencyapproximately 3 to 5 percent. Whole soybeanshave an approximate feeding value of 90 to95 percent that of soybean meal. The followingequation can be used to determine if feeding full-fat soybeans is economically justified:

A = .86Y + .17Z - (S + C), where:A = cost advantage per ton of full-fat productY = cost of one ton of 44 percent soybean mealZ = cost of one ton of feed grade fatS = cost of one ton of soybeansC = cost of processing one ton of soybeans

If it is feasible to feed full-fat soybeans, A willbe greater than zero.

What are the effects of excessivedrying temperatures on protein?

Excessive heat will reduce the availability ofthe amino acids, particularly lysine, in feed ingre-dients. If your soybean meal or dried whey looksdarker than usual or has a burnt smell, it is pos-sible that the protein quality has been reduced.

Will synthetic amino acidsimprove protein quality?

Synthetic amino acids, if added properly,can reduce feed costs and maintain pig perfor-mance. Lysine and methionine are the two feed-grade amino acids most commonly added toswine diets. However, in the future, syntheticthreonine and tryptophan may be availableat prices low enough to add to swine diets.Research has demonstrated that supplementallysine can reduce the amount of soybean mealneeded in swine diets. Therefore, adding syntheticlysine can reduce the crude protein level of thediet without affecting performance. The most com-mon source of synthetic lysine is L-lysine mono-hydrochloride, which is 78 percent lysine. In dietsfor pigs, 100 pounds of 44 percent crude proteinsoybean meal can be replaced by the addition of3 pounds L-lysine HCl and 97 pounds grain perton. If the 3 pounds L-lysine HCl and 97 poundgrain are cheaper than 100 pounds of 44 percent

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crude protein soybean meal, the diet costs wouldbe reduced by using supplemental lysine. How-ever, the use of synthetic lysine is generally notadvisable in gestation or lactation diets. Syntheticlysine has been shown to be poorly utilized inpigs fed only once a day (gestating sows) com-pared with pigs fed ad libitum. In lactation, addingsynthetic lysine alone to the diet, decreases theamount of other amino acids relative to lysine.This results in deficiencies of other amino acidswhich will reduce litter weaning weights.

What is “amino acid balance”and “ideal protein”?

Protein sources vary greatly in quality andquantity. Protein quality is directly dependent onthe content of the most limiting amino acid rela-tive to the pig’s requirement. If a diet is not bal-anced correctly, a shortage of one of the essentialamino acids will reduce growth rate and perfor-mance. An amino acid imbalance may occur if asecond limiting amino acid is added to a dietwhen the first limiting amino acid is still deficient.This will result in a reduction in feed intake andreduced pig performance. On the other hand,when a diet is balanced for the most limitingamino acid (usually lysine), other amino acids areusually in excess of the pig’s requirement. Somecommercial companies are using the concept ofamino acid balance or ideal protein in their salespromotions. This refers to formulating a diet inwhich all amino acid levels are very similar to thepig’s requirement without excesses. However,there is no scientific information to indicate thatthe excesses of amino acids that naturally occurin milo- or corn-soybean meal-based diets willhave a detrimental effect on pig performance.However, the use of low protein, amino acid forti-fied diets may decrease nitrogen excretion inmanure and the environment.

Are amino acid requirements differentfor maximum gain, feed efficiency,and carcass leanness?

Suggested amino acid recommendations areusually based on the amount of an amino acidrequired to maximize rate of gain. However, slightlyhigher levels of amino acids will further improvefeed efficiency and carcass leanness. This isbecause the higher amino acid levels allow theanimal to deposit greater amounts of lean tissuerather than fat. Because it takes less energy todeposit lean than fat, feed efficiency is improved.Slightly higher levels of amino acids may be eco-nomical to producers who market their hogs on alean value system, where there is incentive forproducing lean pork. Suggested dietary lysine con-centrations based on a pig’s fat free lean index areincluded in the factsheet, Growing–Finishing PigRecommendations, MF2301.

Do barrows, gilts, and boars havethe same requirements for amino acids?

On an amount-per-day basis, barrows andgilts require similar amounts of amino acids. How-ever, because gilts typically consume 1⁄2 poundless feed per day than barrows, they may not eatenough to fully meet their requirements. Althoughsometimes difficult to accomplish on the farm,split-sex feeding may offer some feeding andmarketing alternatives. Split-sex feeding involvessorting gilts from barrows and feeding each sepa-rate diets. Because gilts consume less feed thanbarrows, their diets can be fortified with extraamino acids for growth rate and feed efficiencyas well as calcium and phosphorus for bonedevelopment, if they are going to be retained forthe breeding herd. Marketing programs takingadvantage of the better feed efficiency of gilts canalso be utilized with split-sex feeding. In general,we typically recommend feeding gilts a diet con-taining .05 to .10 percent more lysine than thediet for barrows. Additional information and sug-gested lysine levels for producers who split-sexfeed are listed in the factsheet, Growing–FinishingPig Recommendations, MF2301.

How does lean growth potentialaffect amino acid requirements?

Increased selection for lean pork productionhas opened opportunities for further refinement ofnutrient requirements based on genetic potentialfor protein deposition. It is intuitive that a lean,rapidly growing pig will have a higher amino acidrequirement than a fat, slow growing pig. There-fore, suggested dietary lysine levels for pigs ofdifferent growth potential are listed in the fact-sheet, Growing–Finishing Pig Recommendations,MF2301.

How will high ambient temperaturesaffect my pigs?

High ambient temperatures result in manyphysiological changes in the pig. High tempera-tures will decrease feed intake which will in turndecrease average daily gain. However, this willfrequently result in increased carcass leannessbecause of decreased energy intake. In the past,we have recommended to increase dietary lysineconcentrations and possibly add fat (if economi-cally justified) to offset the decreased nutrientintake. However, while research data has shownthat this practice will improve growth perfor-mance, it will not increase performance to thesame level as pigs housed in a thermoneutralenvironment. In theory, if a pig has decreaseddaily gain, its lysine requirement should decrease;however, if carcass leanness increases, therequirement should increase. Therefore, thesetwo opposing factors could potentially nullify anyneed to adjust diets for warm weather. Therefore,

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during the summer months, it is advisable to pro-vide drip cooling, or some other method to keeppigs cool. If diets are adjusted based on season,it is advised that they be increased no more than.05 percent in finishing diets. Further research isneeded to help solve this dilemma.

What are digestible amino acids?Although two protein sources may contain

the same amounts of a certain amino acid,because of some difference in the chemical struc-ture of the protein, processing method, or anti-nutritional factor, not all of that amino acid may bedigested or available to the pig. This is especiallytrue for certain by-product feed ingredients or feedingredients that have been over-processed. Moreand more information about amino acid digestibil-ity is being published for a variety of by-productfeed ingredients, such as cottonseed meal, meatand bone meal and blood meal. If you are usinga high percentage of these feed ingredients, youmay want to consider balancing the diet on adigestible amino acid basis. Because of the limitedinformation on digestible amino acid values iningredients and requirements, we highly recom-mend professional guidance when working on adigestible amino acid basis. However, if you areusing milo or corn and soybean meal, there isprobably no need to worry about formulating ona digestible amino acid basis.

What is the difference between total,apparent, and true digestibilities?

Generally, the gross concentration of anamino acid in a feed ingredient is considered its“total” value. Measuring the amino acid intakeversus difference from what is excreted at the endof the small intestine is generally referred to as an“apparent digestible” amino acid concentration.This procedure requires that the pigs be surgi-cally cannulated at the end of the small intestineto collect the digesta samples. Finally, “true”digestibility values are calculated from apparentdigestibility values by further determining theamount of endogenous amino acid loss viasloughed intestinal cells and digestive enzymes.Because of differences in the digestibility coeffi-cients and potential confusion between express-ing requirements as either total, apparent, or truedigestibilities, again, it is highly recommendedthat you get professional guidance when workingon a digestible amino acid basis.

Is calorie:protein ratio important?A pig will adjust its feed intake to a certain

extent to meet its energy requirement. Therefore,when the energy density of the diet increases, apig will tend to eat less feed. Thus, in diets withadded fat, it is important to increase the concen-tration of amino acids. By increasing the concen-tration of amino acids in the diet, the pig will

consume approximately the same amount per dayeven though feed intake is less. Currently there islimited information on the optimum calorie:proteinratios for pigs. Factors such as feed intake, genet-ics, environment, and rate and composition ofgain may affect the calorie:lysine ratio. Generalguidelines for amino acid fortifications as well asproposed calorie:lysine ratios are presented inthe factsheet, Growing–Finishing Pig Recommen-dations, MF2301.

MineralsMinerals constitute a small percentage of the

swine diet, but their importance to the health andwell-being of the pig cannot be over-emphasized.Minerals have been classified into two types;macrominerals and microminerals. Macrominerals(major minerals) that are commonly added toswine diets are calcium, phosphorus, sodium,and chlorine (magnesium and potassium are alsorequired but are adequately supplied by grains).Microminerals (minor or trace minerals) of primaryconcern are zinc, copper, iron, manganese,iodine, selenium and chromium.

Functions of minerals are extremely diverse,ranging from structural functions in some tissues toa wide variety of regulatory functions. The increas-ing trend toward confinement rearing of pigs,without access to soil or forage, increases the im-portance of meeting dietary mineral requirements.

What other trace minerals may be important?Other trace minerals have been shown to be

essential for chicks or laboratory animals andmay be required by swine. These include molyb-denum, cobalt, fluorine, nickel, silicon, vanadium,tin and arsenic. Whether these elements will be ofpractical significance awaits further research.Most of them are believed to be present inadequate quantities in natural feed ingredients.However, the use of simpler swine diets withfewer ingredients may necessitate considerationof their importance in the future.

What occurs if high levels of minerals are fed?Minerals should not be added haphazardly.

The old adage, “if a little is good, more is better,” isnot true when adding minerals to swine diets.If minerals are added without reason, more harmthan good can occur. All minerals have a toxic level.

Some minerals, particularly calcium, ifadded in excess will interfere with absorption ofother nutrients. As an example, calcium interfereswith zinc absorption and results in a skin disordercalled parakeratosis. A combination of a high levelof calcium (over 0.9 percent) and marginal zinclevel can result in this condition. Never mix addi-tional minerals with a commercial supplement,unless the need is specified on the tag.

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Why are calcium and phosphorus important?These two elements are important in skel-

etal structure development, but their presence insoft tissues is also vitally important. They both aidin blood clotting, muscle contraction, and energymetabolism. About 99 percent of the calcium and80 percent of the phosphorus in the body arefound in the skeleton and teeth. Therefore, defi-ciency of calcium and phosphorus will result inimpaired bone mineralization, reduced bonestrength, and poor growth. Young pigs with a defi-ciency of calcium and phosphorus will have clinicalsigns of rickets. Mature pigs eating a deficient dietwill remove calcium and phosphorus from the bone(osteoporosis), decreasing bone strength. This canresult in a condition called “Downer Sows” and canbe prevented by proper diet formulation.

What are the major sources ofcalcium and phosphorus?

The ingredients used in swine diets varywidely in mineral content. Most cereal grains areparticularly low in calcium. Phosphorus content ofcereal grains is largely phytate phosphorus, whichis poorly utilized by swine. Several researchersare currently evaluating the availability of phos-phorus in cereal grains. A range of 8 to 60 per-cent of phosphorus availability has been reportedin cereal grains, but for practical purposes, anavailability of 30 percent is a reasonable estimate.

Feeds of animal origin, such as meat andbone meal, tankage, or fish meal, are quite highin calcium and available phosphorus. Thus, thelevel of supplemental calcium and phosphorusmust be recalculated as feeds of animal originreplace soybean meal in the swine diet.

The standard ingredients for supplyingsupplemental calcium are limestone or oystershell. Phosphorus is primarily supplied bydicalcium phosphate or monocalcium phosphate.Table 8 lists a number of feed ingredients thatmay be used to supply calcium and phosphorus.

It should be noted that many of the sources sup-ply both calcium and phosphorus, so the quantityof limestone in the diet must also be adjusted. It isextremely important to check the nutrient specifi-cations of these mineral sources, because thelevel of calcium and phosphorus may be differentfrom the above values.

What is phytate phosphorus?Approximately 50 to 70 percent of the phos-

phorus contained in plant products is in a form thatis unavailable to the pig. The unavailable form ofphosphorus is called phytate phosphorus. As aresult, swine diets generally contain large amountsof phytate phosphorus which is not digested andexcreted in manure. Many swine diets are formu-lated on a “total” phosphorus basis, i.e., taking intoaccount all of the phosphorus contained in thegrain, protein source and mineral supplements.Total phosphorus requirements generally corre-spond to an available or digestible phosphorusrequirement with simple milo- or corn-soybeanmeal based diets. However, because of the grow-ing concern about phosphorus excretion into theenvironment, formulating on an available phos-phorus basis would assist in minimizing excessphosphorus excretion, especially when using alter-native or by-product ingredients. Because of thevariation in phosphorus availability estimates iningredients and the potential for use of phytase, anenzyme which helps breakdown phytate phospho-rus, we encourage professional assistance withevaluating available phosphorus requirements.

What is phytase and should Iadd it to my swine diets?

Phytase is an enzyme that when added toswine diets increases the digestibility of phytatephosphorus. Increased digestibility of phytatephosphorus will reduce the need for expensiveinorganic phosphorus supplementation andreduce phosphorus excretions by the pig. Currentrecommendations suggest that if phytase is

Table 8. Sources of Calcium and Phosphorus.

Source Mineral % Remarks

Ca P

Ground limestone 38 0 Good availability, usually the cheapestsource of Ca. May contain 35% Ca.

Dicalcium phosphate 21 18.5 Good availability, levels may vary.Monocalcium phosphate 18 21 Good availability, levels may varyTricalcium phosphate 38 18Sodium tripolyphosphate 0 25 Usually a more expensive source of P.Disodium phosphate 0 21Defluorinated rock phosphate 32 18 Availability varies.Steamed bone meal 28 14Meat and bone meal 9.4 4.58Tankage 4.6 2.5Fish meal 5.2 2.88

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added to the diet, the total phosphorus concentra-tion can be reduced by .10 percent withoutdetermintal effects on pig performance. Therefore,without an allowance for decreased phosphorusexcretion in swine waste, the cost of the addedphytase needs to be evaluated versus the cost ofthe phosphorus supplement.

How can I determine which is thecheapest source of phosphorus?

Phosphorus is the second most expensivenutrient and most expensive mineral added toswine diets. It is possible to reduce the total costof a diet by evaluating the cost of the supplemen-tal phosphorus. For example, if the cost of dical-cium phosphate (21 percent calcium, 18 percentphosphorus) is $20 per 100 pounds and mono-calcium phosphate (18 percent calcium, 21 per-cent phosphorus) is $25 per 100 pounds, which isthe cheapest source of phosphorus? The cost ofphosphorus per pound is divided by the percent-age of phosphorus to determine the cost perpound of actual phosphorus.

For example:Dicalcium Phosphate20¢/lb = $1.11/lb18% phosphorus of actual phosphorus

Monocalcium Phosphate25¢/lb = $1.19/lb21% phosphorus of actual phosphorus

Therefore, the dical would be a cheapersource of phosphorus.

How should I adjust differentphosphorus sources?

The amounts of calcium and phosphoruscan vary in products commonly called “dical.”Therefore, producers need to know how to adjustthe amount of dical and limestone in their swinediets. In the suggested diets in following chaptersof this publication, 21 percent phosphorus“monocal” was used for formulation. In adjustingthe amounts of monocal or dical and limestone toachieve the desired levels of calcium and phos-phorus, the following example may be helpful:1. The diet has 30 lb of monocal (21% P; 18%

Ca) and 10 lb of limestone (38% Ca).2. You can purchase 18% phosphorus and

21% Ca dical at a lower price per unit ofphosphorus.

3. Determine phosphorus levels:a. 30 pounds of monocal × 21% = 6.3 pounds

of phosphorus supplied by monocal.b. 6.3 lb ÷ 18% = 35 lb of dical (18% P)

needed to replace 30 lb of monocal (21% P).4. Determine calcium levels:

a. 30 pounds of monocal × 18% = 5.4 poundsof calcium supplied by monocal.

b. 35 pounds of dical × 21% = 7.35 pounds ofcalcium supplied by dical.

c. Needed amount of limestone:7.35 pounds of Ca - 5.4 lb of Ca =1.95 pounds of extra Ca.1.95 ÷ 38% Ca = 5.15 fewer pounds oflimestone needed.

5. Results:30 pounds of monocal (21% P; 18% Ca) and10 pounds of limestone can be substitutedfor 35 pounds of dical (18% P; 21% Ca) and4.85 pounds of limestone.

What is the ideal calcium-phosphorus ratio?The optimum levels of calcium and phos-

phorus for various ages of pigs are provided inthe nutrient recommendations in the followingchapters. For maximum performance, minimumdietary levels of each are necessary, as wellas the correct ratio of one to the other. Thedesired ratio of 1.0 to 1.3 calcium to 1.0 totalphosphorus in a grain soybean meal diet is pre-ferred, although if the phosphorus level isadequate, a calcium:phosphorus ratio of 2:1 willnot affect performance. However, recent researchhas shown that when using phytase, maintaininga narrow Ca:P ratio is important.

Do breeding stock need greateramounts of calcium and phosphorus?

Levels of calcium and phosphorus that areadequate for maximum gain in body weight arenot necessarily sufficient for maximum bonedevelopment. Borderline deficiency may go unno-ticed in the growing–finishing pig, but causeserious consequences in those pigs saved forbreeding purposes. With split-sex feeding,replacement gilts can be fed higher levels ofcalcium and phosphorus for maximizing bonedevelopment than market hogs.

Swine producers have reported leg weak-nesses and abnormalities that impair the breed-ing effectiveness of young replacement animals.Many of the leg problems can be attributed tostructural unsoundness. However, inadequatedietary calcium and/or phosphorus can impairbone mineralization and result in weaker bones.Limit feeding replacement gilts the finishing diet,which may reduce calcium and phosphorusintakes, is not advisable.

What is the level of calcium in soybean meal?Calcium carbonate, commonly called ground

limestone, is routinely used to aid in improving theflowability of soybean meal during processing. Inthe past, a value of .20 to .25 percent calcium hasbeen observed in soybean meal, however, thislevel has fluctuated from .20 to over .50 percent.Therefore, as part of a standard quality controlprogram, calcium levels in soybean meal shouldbe periodically checked to minimize potential

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problems. The suggested diets contained in thispublication have been formulated with a .26 per-cent calcium value for soybean meal.

How much salt is needed?Salt, a combination of sodium and chloride,

must be adequate in all swine diets. Grains andplant protein supplements are low in sodium andchloride, but the needs of the growing–finishingpig can be met by adding .25 to .35 percent saltto the diet. When a diet deficient in salt is fed togrowing pigs, depressed performance will be evi-dent within a few weeks. Research has suggested.5 percent added salt is adequate for breedingstock. Even though dried whey and spray-driedblood products contain relatively high levels ofsalt and (or) sodium, recent research has demon-strated improved growth rates when salt is addedin addition to these ingredients.

High levels of salt can be tolerated, if ade-quate drinking water is available. However, ifwater is restricted, as little as .2 percent dietarysalt has resulted in toxicity symptoms.

Why is it necessary to givebaby pigs supplemental iron?

The baby pig is born with a limited supplyof iron, and because the sow’s milk is also low iniron, supplemental iron is a must. The most com-monly used sources of iron to prevent anemia innewborn pigs are injectable and oral products.Injectable iron is the preferred method of anemiaprevention. An intramuscular injection of 200 mgof iron dextran given at 1 to 3 days of age willprevent the anemia problem. Because the concen-tration of iron sources may vary, it is important toevaluate products based on a cost/mg iron basis.

Is a second iron injection necessary?Most producers will give an iron injection

within the first 3 days of life. Need for a secondinjection depends on the amount of iron availableto the baby pigs during the lactation period andhow much was given in the first injection. Thebaby pigs can receive iron orally from consumingcreep feed or sow feed or from the sow’s feces.Over 90 percent of the injected iron from the initialtreatment is utilized over the first 3 weeks. If lessthan 200 mg of iron is given in the first injection,a second iron shot may be needed. Need for asecond injection also depends primarily on bloodhemoglobin concentration, a rapid and reliableindicator of the iron status of the pig. Blood hemo-globin levels of 10 mg/100 ml or above indicateadequate iron status. Hemoglobin levels of 8 to9 mg/100 ml indicate a borderline anemia condi-tion, whereas a value of 7 or below indicates ananemic condition. If blood hemoglobin levels fallbelow the 10 mg/100 ml level, a second iron shotis advisable.

When giving iron injections to baby pigs,what is the best injection site?

For many years, swine producers have beengiving iron injections in the ham. When iron injec-tions are given in the ham, permanent staining ofthe meat may occur. Because ham is one of thehigher value cuts of pork, it is highly recommendedthat iron injections be given in the neck. Additionalinformation regarding iron and medication injectionsites is contained in the National Pork Producer’sCouncil Pork Quality Assurance Program.

Are chelated or complexed mineralproducts beneficial to pig performance?

A chelated or complexed mineral is boundto a compound that helps to stabilize the mineral.Many claims have been made for the benefit ofchelated and complexed minerals. One is thegreater physical stability, which reduces thetendency for trace minerals to segregate in thefeed. Another advantage is for less oxidation ofvitamins and minerals and greater availability.Recent research has shown that chelated miner-als will be 0 to 15 percent more available whichwill decrease the potential concern for excessmineral excretion into the environment. However,their cost may be two to three times greater thanthose of nonchelated minerals. Therefore, thecosts of chelated and complexed minerals mustbe examined before adding them to swine diets.

Should selenium be supplementedin Kansas swine diets?

The need for supplemental selenium isrelated to vitamin E intake. With decreased use ofpasture as a source of vitamin E, artificial dryingof grains that causes partial destruction of vitaminE and increase in the incidence of mulberry heartdisease in Kansas swine herds, supplementalselenium has become more important. Theamount that may be added to swine diets is regu-lated by the U.S. Food and Drug Administrationand is limited to 0.3 ppm (.27 g/ton) for all pigs.

Do I need to add chromium to my swine diets?Recently, the FDA has allowed the use of

chromium in swine diets. Currently, chromiumtripicolinate is the only form approved; however,other forms, such as chromium nicotinate andchromium-yeasts, are currently being evaluated.Some studies have observed increased percent-age lean and reduced backfat thickness in finishingpigs fed added chromium while others have not. Inaddition, some studies have observed increasedfarrowing rate or number of pigs born to sows fedchromium in finishing and gestation and lactation.Because of the variation in response observed toadded chromium, careful evaluation of the cost andpotential benefit (possibly involving on-farm evalua-tion) need to be considered.

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What are the major sources of trace minerals?Iron, copper, manganese, zinc, iodine, and

selenium are the trace minerals that should beadded in a mineral premix. In Table 9, a list ofthe various chemical forms in which the traceminerals are available is shown. Most traceminerals are not generally supplied as purechemicals, but as either ores or industrial by-products. Sulfate trace mineral forms are usuallymore reactive in the premix and possibly reducethe potency of the more susceptible vitamins andreduce the shelf life of the entire premix. However,sulfate forms often have the greatestbioavailability of any of the inorganic sources.

A suggested trace mineral premix withspecified amounts and mineral sources is givenin the factsheet, Premix, Base Mix and StarterDiet Recommendations for Swine, MF2299. Thissingle premix can be used in diets for all ages ofswine by adjusting the inclusion rate for sow,starter, and growing–finishing diets.

VitaminsWhy are vitamins necessary?

Vitamins are required for normal metabolicfunction; development of normal tissues; andhealth, growth and maintenance. Some vitaminscan be produced within the pig’s body in sufficientquantities to meet its needs. Others are present inadequate amounts in feed ingredients commonlyused in swine diets. However, several vitaminsneed to be added to swine diets to obtain optimalperformance. Vitamin needs are more criticaltoday than in previous years because of the useof simple diets containing fewer ingredients andconfinement facilities.

What vitamins should be added?Vitamins that should be added to swine diets

can be divided into two groups—fat-soluble andwater-soluble. The fat-soluble vitamins that aregenerally added are A, D, E and K. The water-soluble or B-complex vitamins which may be defi-cient in a corn- or milo-based diet are: pantothenicacid, riboflavin, niacin and vitamin B12. The

Table 9. Sources of Trace Minerals a.

Mineral Source Mineral, % Remarks

Iron Ferrous sulfate 20.8–32.9 Excellent bioavailabilityFerric ammonium citrate 16.5–18.5 Good bioavailabilityFerrous fumarate 32.9 Good bioavailabilityFerric chloride 20.7 Mediocre bioavailabilityFerrous carbonate 40–43 Bioavailability variesFerric oxide 57–61 Limited bioavailability

Copper Cupric carbonate 57.5Cupric chloride 37.3Cupric hydroxide 65.1Cupric oxide 75–80 Good to excellent bioavailabilityCupric sulfate 25.2 Excellent bioavailability

Manganese Manganese carbonate 47.8Manganese chloride 27.8Manganese oxide 60.0–60.6 All are good sourcesManganese sulfate 27.0–28.4Manganous sulfate 32.5

Zinc Zinc carbonate 56.0Zinc carbonate 48.0 Good bioavailabilityZinc oxide 72–73 Excellent bioavailabilityZinc sulfate 22.7–36.4 Excellent bioavailability

Iodine Calcium iodate 62.0–65.1 Excellent bioavailabilityPotassium iodide 68.7–68.9 Not as stable as other formsCuprous iodide 66.6Pentacalcium orthoperiodate 39.3Ethylenediamine dihydriodide (EDDI) 80.1

Selenium Sodium selenite 45.6 Both have good availability, but bothSodium selenate 41.8 contain 24–27% sodium

a Adapted from AFMA Feed Ingredient Guide.

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recommended levels of addition are shown in thefollowing chapters. In addition, research hasshown that additions of folic acid, pyridoxine,choline, and biotin may improve sow and litterperformance when added to gestation and lacta-tion diets. There is no need to supplement corn- ormilo-soybean meat based diets for growing–finishing swine with biotin, folic acid, pyridoxine,or choline.

What about natural sources of vitamins?Green leafy plants, grasses, and alfalfa are

excellent sources of vitamins for swine. However,with increased confinement rearing and continualusage of pastures and outside lots, very oftenlittle plant material is available. In addition, withfewer ingredients used in diet formulation, there isno longer the variety of feed ingredients to supplyadded vitamins. Finally, vitamin content of grainsand protein sources may be unavailable or lostduring storage. Therefore, when formulating swinediets, we recommend specifying all vitamin andtrace mineral levels as “added” levels. This helpsto eliminate some of the confusion and difficulty indetermining availability and concentrations in feedingredients.

Synthetic vitaminsBecause the natural sources of the vitamins

may not be present in swine diets, it is recom-mended that a vitamin supplement be added. Syn-thetic vitamins are produced by many companiesand are sold individually or in various combina-tions. Synthetic vitamins may be more accessiblethan some of the natural sources of vitamins.

A suggested vitamin premix is listed in thefactsheet, Premix, Base Mix and Starter Diet Rec-ommendations for Swine, MF2299. This premix is

designed to be fed to all ages of pigs by adjustingits inclusion rate. Therefore, it is necessary to usea sow add pack for gestation and lactation diets.Although this single premix is over-fortified oncertain vitamins for pigs, depending on age, thereis less potential for vitamin potency losses duringlong storage.

Base mix recommendationsBecause feed processing systems differ

from farm to farm, several base mix recommenda-tions have been included in the factsheet, Premix,Base Mix and Starter Diet Recommendations forSwine, MF2299, for producers who do not chooseor do not have the milling capabilities to handlethe small inclusion rates associated with a premixprogram. These base mixes contain approxi-mately the same calcium, phosphorus, vitamin,and trace mineral levels as diets formulated withpremixes. Furthermore, these base mixes can besubstituted for the individual ingredients (mono-calcium phosphate, limestone, salt, vitamin andtrace mineral premixes) in the suggested dietformulations and provide similar nutrient content.

Vitamin stabilityEven though the vitamin premix was cor-

rectly formulated before leaving the manufacturer,it does not necessarily mean that it will haveadequate levels of vitamins to meet the pig’s dailydietary requirements. Premix abuse can contrib-ute to borderline vitamin deficiencies. In Table 10,factors that affect vitamin stability are shown.Some vitamins are much less stable than others;therefore, care of the vitamin premix is extremelycritical for optimum performance. Vitamins, classi-fied by their stability are listed in Table 11. In addi-tion, because choline, trace minerals, and

Table 10. Factors that Affect Vitamin Stability a.

Vitamins Factor

Fat-soluble vitaminsVitamin A Heat, oxidation, and moistureVitamin D HeatVitamin E Heat and moistureVitamin K Minerals

Water-soluble vitaminsRiboflavin Natural and ultraviolet lightNiacin MoisturePantothenic acid pH and presence of electrolytesVitamin B

12Oxidation, minerals, and vitamin C

Choline MoistureFolic acid Temperature and moisturePyridoxine Light and heatThiamin Sulfate mineral forms, pH, and temperatureVitamin C Oxidation

a Adapted from Diamond–Shamrock Feed Supplement Products Manual.

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different processing methods can increase thepotential for vitamin oxidation, monthly vitaminlosses are also listed in Table 11. To maintainvitamin potency, it is highly recommended thatvitamins be stored in a dry, cool, dark place.Because vitamins are hygroscopic (absorb mois-ture) vapor barriers such as plastic-lined sackswill aid in reducing moisture levels, especiallywhen the humidity is high. If choline and traceminerals are present in combination with the vita-mins in the premix or base mix, storage timeshould not exceed 60 days.

Should choline be supplementedin swine diets?

Choline is important in nerve function, pro-tein synthesis, and structural development. Cho-line in the strict sense is not a vitamin, becausepigs can synthesize sufficient choline for theirneeds, provided that specific chemical sub-stances are available. Choline is one of the mostexpensive vitamins added to premixes. It mayrepresent 10 to 25 percent of the cost of vitaminsupplementation. The cost of choline in gestationdiets can be justified by the increase in the num-ber of live pigs born and weaned when it is addedat the rate of 500 grams per ton of complete feed.

In the past, the cause of spraddle legs inbaby pigs has been attributed to a deficiency ofcholine. Research indicates that choline defi-ciency is not a major factor in this condition. Thecause(s) of spraddle legs is not fully understood,

but it may involve several factors including: genet-ics, management, slick flooring, mycotoxins, anda virus or combination of viruses.

Although the requirement for choline has notbeen defined, 150 grams per ton of complete feedis recommended as a safety factor for pigs lessthan 15 pounds, but not for growing–finishing pigs.

How much vitamin E should beadded to swine diets?

There is much debate as to how muchvitamin E should be added to swine diets. Thisis a result of the many factors that influence vita-min E concentrations and requirements. Some ofthese include: artificial drying of grains, storagetime and conditions, unsaturated fatty acids, andselenium concentrations. Because of the highincidence of Mulberry Heart Syndrome in Kansasswine herds, we recommend that 40,000 IU/tonof vitamin E be added to sow and baby pig diets.

Why is vitamin K (menadione) added?Although vitamin K occurs in many natural

feedstuffs and is also synthesized by intestinalmicroflora of the pig, a deficiency can be causedby low stability and moldy feeds. Deficiency char-acteristics are hemorrhaging and prolonged bloodclotting time, but can also include blood-tingedurine, lameness and listlessness. When specify-ing vitamin K requirements, it is important to indi-cate menadione, which is the active form of thevitamin.

Table 11. Vitamin Stability in Premixes, Pelleting and Extrusion a.

Stability

Very high High Moderate Low Very low

Vitamin Choline Riboflavin Thiamine Thiamine HCl MenadioneChloride

B12

Niacin Folic Acid Ascorbic acid

Pantothenic Pyridoxineacid

E D3

Biotin A

Losses per month, %

Premixes without 0 <0.5% 0.5% 1% 2%choline and trace minerals

Premixes with choline <0.5% 0.5% 2% 4% 6%

Premixes with choline <0.5% 1% 8% 15% 30% and trace minerals

Pelleting 1% 2% 6% 10% 25%

Extrusion 1% 5% 11% 17% 50%a Source: BASF Technical Bulletin.

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Is it necessary to addvitamin C to swine diets?

Several experiments have been conducted todetermine the value of supplemental vitamin C orascorbic acid in swine diets. The majority of theresearch indicates that vitamin C supplementationwill not improve pig performance. However, someresearch has suggested that added vitamin Cincreased sperm production in heat stressed boars.

What is carnitine, and do Ineed to add it to my swine diets?

Carnitine is a vitamin-like compound prima-rily responsible for transporting fatty acids acrossthe mitochondrial membrane. Recent research hasobserved finishing pigs fed added carnitine to havereduced backfat thickness. Carnitine may alsoincrease birth and weaning weights when fed tosows. However, like chromium, careful evaluationof the cost and potential benefits (possibly involv-ing on-farm evaluation) need to be considered.

Is it necessary to addpyridoxine to swine diets?

Pyridoxine (vitamin B6) was generally thoughtto be adequate in a grain-soybean meal-based dietto meet the pig’s requirement. However, recentresearch has observed an improvement in growthperformance of weanling pigs fed 3 g/ton of addedpyridoxine. However, this improvement was onlyobserved the first two weeks after weaning. There-fore, because it appears for now that older pigsmay not need added pyridoxine, we suggest add-ing 3 g/ton in SEW and Transition diets.

Is it necessary to add biotin,pyridoxine, and folic acid to sow diets?

Biotin, pyridoxine, and folic acid are water-soluble vitamins that have been studied to evalu-ate their influence on overall reproductiveperformance. Biotin deficiency has been associ-ated with foot lesions and toe cracks in sows.However, research is contradictory, with someexperiments finding benefit from biotin additionsand others not. The availability of biotin in grainmay be a possible factor for these discrepancies.Therefore, 200 mg/ton biotin is recommended tobe added to sow gestation and lactation diets asan insurance factor.

Pyridoxine has typically not been recom-mended for use in sow diets because theamounts in grain and soybean meal were thoughtto be adequate to meet the sow’s requirement.However, research from Canada recently demon-strated increased number of pigs born to sowsfed added pyridoxine. Therefore, 13,750 mg/tonpyridoxine is recommended to be added to sowgestation and lactation diets.

Folic acid participates in many enzymaticreactions that appear to be essential in assuringembryo survival. Research has indicated that the

addition of 1,500 mg/ton of complete feed willincrease the number of pigs born alive byapproximately 1 pig per litter.

What management changes haveaffected vitamin and mineral nutrition?

In the last 10 to 15 years, vitamin and tracemineral additions have become increasinglyimportant because of changes in feeding, housingand management systems. Some of the moreimportant changes include:1. Increased confinement production has denied

swine access to soils and grazing crops,which provided vitamins and minerals.

2. Increased use of slotted floors has preventedrecycling of feces, which may be high inB-vitamins and vitamin K that are synthesizedby microorganisms in the large intestine.

3. Reduced use of multiple protein sources indiets. If multiple protein sources are used,they often complement each other in provid-ing the vitamin and mineral needs of swine.

4. Reduced daily feed intake during gestation.Dietary vitamin and mineral concentrationsmust be increased as daily feed intake isdecreased. With the trend towards movingsows from outside gestation lots into environ-mentally controlled buildings, maintenancerequirements and feeding levels will be low-ered. Therefore, to prevent shortages withdecreased feed intake, vitamin and mineralrequirements should be expressed on anamount/day basis rather than percentages.

5. Earlier weaning of pigs. There is increasingpressure to wean pigs at an earlier age. Two-and 3-week weaning is commonplace. Asweaning age decreases, the quality of the dietwith respect to all nutrients becomes morecritical.

6. Bioavailability of nutrients in heat-dried grainsand feed ingredients appears to vary widely.Inhibitors and molds in feed may result inreduced absorption, thereby increasingrequirements for certain vitamins.

Should I eliminate vitamin and trace mineralpremixes from late finishing pig diets?

As the pig approaches market weight, theneed for high levels of vitamins and minerals formaximum growth rate appear to decrease. In fact,recent research suggests that for the last 40 to50 pounds of gain, added vitamin and trace min-eral premix may not be necessary for maximumlean growth and carcass characteristics. Therefore,some producers may attempt to take advantageof the $.25 to .30 per pig savings by removing thevitamin and trace mineral premixes in late finishing(last 40 to 50 pounds of gain). However, producersshould be made aware of the potential disadvan-tages of this management practice.

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1. Removal of vitamin and trace mineralpremixes is not recommended for replace-ment gilts destined to enter the breeding herd.

2. Feeders must be emptied in between groupsof pigs so that leftover feed will not be fed thenext group of pigs. Starting growing pigs on adiet without vitamin and trace minerals evenfor a short time could negate any potentialsavings later in the finishing stage.

3. Barns need to be run strictly on an all-in-all-out basis. Pigs not marketed and transferredinto the next marketing group could endup being fed the late finisher diets for anextended period resulting in deficiencies.

4. Field reports have indicated an increase inthe incidence of fractured bones in pigs fedvery low Ca and P or diets without addedCa and P during processing. These fractureslead to increased trim loss that will offset thepotential savings. Therefore, the reduction inminerals should not be too severe, nor thelength of feeding more than the recom-mended last 40 to 50 pounds of gain.

5. Although current research data suggests nodetrimental impact of removing the vitaminand trace mineral premixes on pork qualitytraits, such as color or shelf-life, more indepthresearch on the effects on pork’s nutritionalvalue and its impact on consumer attitudestowards pork need to be determined.

WaterWhy is water important?

Water is so common we seldom think of it asa nutrient, but it is probably the most essential andthe cheapest of all nutrients. Depriving pigs ofwater reduces feed consumption, limits growth andfeed efficiency, and causes lactating sows to pro-duce less milk. Water affects many physiologicalfunctions necessary for maximum animal perfor-mance. Among these are temperature regulation,transport of nutrients and wastes, metabolic pro-cesses, lubrication and milk production.

How much water do pigs need?The water requirements of swine are variable

and governed by many factors. Water accounts foras much as 80 percent of body weight at birth anddeclines to approximately 50 percent in a finishedmarket animal. The need for water is increasedwhen a pig has diarrhea. High salt intake, highambient temperature, fever, and lactation alsomarkedly increase water requirement.

Water requirement has a relationship to feedintake and to body weight. Under normal condi-tions, swine will consume 2 to 5 quarts of waterper pound of dry feed or 7 to 20 quarts of waterper 100 pounds of body weight daily. A rule of

thumb is that self-fed hogs will consume one anda half to two times as much water as feed.

Temperature will affect water intake. Addi-tional energy is required to warm liquids con-sumed at temperatures below that of the body.Lactating sows must have unlimited access towater (about 5 gallons a day) if they are to milkadequately, and suckling pigs past 3 weeks ofage need water in addition to that in sows’ milkfor optimum performance. Free access to waterlocated near feeders is desirable.

Will water flow rate affect performance?Recent research has shown that water flow

rate will have little effect on growing-finishing pigperformance. However, pigs will take longer todrink when water flow rate is reduced. Suggestedwater flow rates based on phase of productionare listed below:

Recommended Water FlowsNursing pigs and hot nursery pigs:- 1 cup (250 cc) of water per minute.Pigs from 25 to 50 lb (nursery):- 2 cups (500 cc) of water per minute (1 pint).Pigs from 50 to 125 lb (grower):- 3 cups (750 cc) of water per minute.Finishing hogs, 125 lb to market:- 4 cups (1000 cc) of water per minute

(1 quart).Sows (gestation and lactation) and boars:- 4 cups (1,000 cc) of water per minute

(1 quart).

Is wet feeding beneficial to pig performance?There has been renewed interest in wet

feeding, and several “wet” feeders are availableon the market. Research with starter pigs hasindicated that wet feeding results in poorer feedefficiency. However, research with finishing pigshas shown a slight improvement in feed conver-sion and approximately 50 percent less waterwastage; thus, reducing manure storage require-ments. Probably the biggest concern with wetfeeding is the increase potential for spoilage andmold problems from wastage. Therefore, if usingwet feeders, feeder management and cleaningwill be increased.

Will high levels of minerals in thewater source affect performance?

Saline waters are found occasionallythroughout the United States and cause concernabout their use as drinking water for man andlivestock. Minerals most commonly found inground and surface waters are sulfates, chlorides,bicarbonates, and nitrates, which form salts withcalcium, magnesium, or sodium. The combinedconcentrations of these minerals are called totaldissolved solids. Heavy applications of fertilizers

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Feed processing systemsThere are basically four systems of prepar-

ing diets for a swine operation. The goal for anutrition program should be to provide each pigat the feeder with quality feed at a cost-effectiveprice. This is not the same as least cost per tonof feed produced. Outlined below is a briefdescription of each system of diet preparation.A. Complete Feed. Complete feeds are pre-

pared and delivered by a commercial mill as aready-to-feed product. Toll milling, where alocal feedmill will prepare customized dietsbased on a producer’s specifications, isquickly becoming an economical alternativeto on-farm feed manufacturing in some areas.

B. Grain and Supplement. Mixing producer-raised grain and supplement has been popularfor a long time. In most cases, a basic 40 per-cent protein supplement is added to grain toprovide the proper nutrients. This system maybe more expensive than the base mix system.

C. Base Mix Program. Base mixes contain allneeded ingredients except grain and proteinand usually account for 2.5 to 5 percent of thediet by weight. Base mixes are a cost-effec-tive way to make swine diets on the farm andfit well with many portable feed systems.Base mixes also work well with volumetricand stationary mills. The terminology “premix”is often used erroneously by some feed com-panies to describe their base mix products.

D. Premix Program. Premixes offer the greatestopportunity for specifically tailored diets at alower cost. Accuracy in preparation and ingre-dient care are critical in good premix dietformulation. When equipment and personnelallow, a premix program is suggested as themost precisely designed and cost-effectivediet preparation system. Premixes of vitaminsand trace minerals are added with macrominerals (dicalcium phosphate, limestone,and salt) to a protein and grain mixture.

As a producer assumes more responsibility formixing their own feed, diet costs may be decreased.However, often the producer is unaware of theincreased demands associated with on-farm feedpreparation. The producer must supply additionalfacilities, labor, and quality control over a wide rangeof feed ingredients as well as provide the purchas-ing functions for all inputs into the program. Thisincludes nutrient variability, vitamin and mineralstability, as well as adequate storage, processing,and mixing of diets. Therefore, before consideringchanging from one level of diet formulation to thenext, the producer must be aware of the advantagesand disadvantages of on-farm feed preparation.

In addition to increasing responsibility forquality control, management, labor, and diet for-mulation, there will be increased capital invest-

to fields, contamination of run-off water by animalwastes, and severe drought can increase thepotential for water quality problems.

Sulfates. Sulfate salts are of special concernbecause of their laxative effects. Some effectsof high levels of sulfates in drinking water forswine are: (1) diarrhea, (2) poor gains and feedefficiency, (3) nervousness, (4) stiffness ofjoints, (5) increased water consumption, and(6) decreased food intake. Researchers havereported an increase in scouring of growing pigsconsuming water containing 3,000 parts per mil-lion sulfates, but gain and feed efficiency were notaffected. This level of sulfates did not adverselyaffect reproductive performance of sows.

Nitrates/Nitrites. Nitrites impare the oxygen car-rying capacity of the blood by reducing hemoglo-bin to methemoglobin. The conversion of nitrate tonitrite in water is necessary for toxicity to occur.Research has indicated that approximately 100ppm nitrate nitrogen is generally safe. However,300 ppm nitrate nitrogen can result in toxicity.

Total Dissolved Solids. It appears that for swine,moderate contamination of water supplies by sul-fates or nitrates may be intensified by concentra-tions of other dissolved minerals. Total dissolvedsolids measures minerals that contribute to thesalinity of the water, such as sodium chloride, andcalcium and magnesium salts. High TDS maylower the toxicity levels for sulfates and nitrates.Approximately 5,000 parts per million appears tobe the maximum safe level of total dissolved sol-ids in drinking water for swine without adverseaffect on performance.

Feed ProcessingGrinding is the most common method of

feed processing for the swine producer and nearlyall feed ingredients will be subjected to some typeof particle size reduction. Particle size reductionincreases the surface area of the grain, allowingfor greater interaction with digestive enzymes,thereby improving feed efficiency. Grinding alsoimproves the ease of handling and mixing charac-teristics. However, fine grinding will increase theenergy costs of feed processing and may resultin the feed bridging in feeders and bulk bins,increased dustiness, and the potential for gastriculcers. Therefore, the increased costs of fine pro-cessing must be offset by the resulting improvedfeed conversion. For more details on specificareas of feed manufacturing, the Feed QualityAssurance Handbook offered through theDepartment of Grain Science and Industry is arecommended reference and the NPPC FeedPurchasing Manual.

24

ment (i.e. storage bins, mixing and weighingequipment, tractors, etc.) with on-farm mixing.Very often, these costs are underestimated, and itis important to emphasize that these services areprovided when complete feed is purchased.

However, as you move from complete feedto a premix program, you increase diet flexibility.Diets can be specifically formulated to fit youroperation, facilities, genetics and environment.Probably the biggest advantage with taking moreresponsibility in mixing your own feed is a pos-sible reduction in feed cost. This is accomplishedby not paying someone else to ensure quality dietformulation. The National Pork ProducersCouncil’s Feed Purchasing Manual provides addi-tional information on the pros and cons of feed oringredient purchasing.

What is the optimum particle size?There has been a lot of confusion concern-

ing the optimum particle size of swine diets. Thishas been a result of broad classifications like“fine, medium and coarse,” used to define particlesize. In addition, different grains, because of theirkernel size, hardness, shape, and moisture con-tent will produce a different particle size whenground through the same screen. The rate atwhich grain enters the hammermill or roller millcan also influence particle size. At present, con-sidering improvements in feed efficiency, pro-cessing costs, incidence of gastric ulcers, andpotential for bridging, we recommend an averagediet particle size of 700 microns. In addition, fine(600 to 700 microns) grinding of high-fiber feedingredients has been shown to improve their feed-ing value. As a rule of thumb, if there are wholekernels in your feed, it is probably not ground fineenough, and you may be losing 5 to 8 percent infeed efficiency. Results of over 6,500 samplesanalyzed at K-State since 1985 indicate that70 percent of the samples are over 800 micronsin particle size.

Should I process my feed with ahammermill or a roller mill?

This is one of the most frequently askedquestions concerning particle size reduction.Either mill, if properly designed, is capable ofproducing the desired particle size. However,there are advantages and disadvantages thatmust be considered to determine the best mill foryour operation. Hammermills can change fromgrinding one grain to another by changingscreens. However, a hammermill requires moreenergy than a roller mill and will produce a higherpercentage of fines and dust. A roller mill requiresabout 28 percent less energy to produce a700 micron particle size than a hammermill, butif grain types are to be changed frequently, theroller mill will need to be adjusted for each grain.

For processing grain with a hammermill, screensize will vary based on type of grain. Corn andwheat may be processed through a hammermillequipped with a 5⁄32- or 3⁄16-inch screen, whereasa 1⁄8-inch screen is recommended for processingmilo, barley, and oats. By using these screenswith the respective grain, approximately a700 micron diet particle size should be achieved.

Condition of screens and rollers will be criti-cal in grinding efficiency and maintaining optimumparticle size. Screens and hammers need to bechecked at least monthly for wear and replacedif screen damage occurs or if the holes becomefunnel shaped. Hammers can also be reversed orreplaced if they become worn. In roller mills, threecriteria are essential in producing a 700 micronparticle size: (1) the rolls should be moving with adifferential drive of one roll moving 50 to 75 per-cent faster than the other to produce a shearingaction that will help “cut” the kernel rather thancrush it; (2) The rolls should have corrugations tohelp slice the grain, with the desired corrugationsper inch of roll being 8 to 10 for corn, 10 to 12 forwheat, barley, and oats, and 12 to 14 for milo;(3) the corrugations should have a 1- to 2-inchspiral to increase the shearing potential and elimi-nate fines. In addition, it is generally easier toproduce feed with a 700 micron particle size witha double high roller mill compared with a singlepair roller mill. Magnets and scalpers are veryimportant to remove any metal objects from thegrain and increase the longevity of hammers,screens and rollers. Both hammermills and rollermills should be checked periodically for wear.

How beneficial are otherprocessing methods?

There are many different methods for pro-cessing feed for pigs. In addition to grinding, themost common forms of feed processing arepelleting, expanding, extruding and roasting.Pellets can be made of different lengths, diam-eter, and degree of hardness. The ingredients ofthe diet will influence the hardness of the pelletand pellet quality. Various studies suggest a 3 to10 percent improvement in growth rate and feedefficiency when pigs are fed pelleted diets com-pared to a meal. This appears to result from lessfeed wastage with pelleted feeds. Pelletingappears to improve the nutritional value of high-fiber feed ingredients to a greater extent than thatof low-fiber ingredients. This may be a result ofincreasing the bulk density of the feed. As withany feed processing method, the increased pro-cessing cost must be offset by the improved feedefficiency of pigs fed the pelleted diet.

Expanding. Expanding (high-shear condi-tioning) converts mechanical energy into frictionalenergy to modify (cook) certain components ofthe diet. This process is typically performed prior

25

to and in conjunction with pelleting. Current datawould suggest limited improvements in growthperformance of pigs fed expanded diets. However,the most consistent improvements associatedwith expanders are in the areas of pellet quality,pellet throughput, and improved microbiologicalcontrol of the complete feed.

Extrusion and Roasting. Extrusion process-ing involves the application of heat, pressure, and(or) steam to an ingredient or diet. Extruders aresometimes used for on-farm processing of soy-beans. If properly heated, this is an easy way toadd fat to swine diets and utilize home grown soy-beans. Research has shown that moist extrudedsoy protein concentrate or soybean meal as wellas dry extruded whole soybeans are excellentprotein sources for baby pigs. Because of volume,tonnage, and processing costs, extrusion of com-plete feeds is usually not economically justifiedbased on performance of pigs fed extruded com-plete feeds. Extrusion processing increases thebulkiness of the diet, making it more difficult for thepig to consume enough feed to meet its nutrientrequirements. Roasting can also be used to pro-cess home-grown soybeans. This can also be analternative method for adding fat to swine diets.However, roasting temperature and times must bechecked to ensure adequate processing. Theadded cost of the extruded, or roasted productsmust be the ultimate consideration in determiningthe feasibility of their use in swine diets.

Other Processing Methods. Several alter-native processing methods are available to swineproducers. Steam flaking, micronizing, and otherprocessing methods often do not improve pigperformance enough to justify the added expenseof processing. When evaluating the expense offeed processing methods, the following equationwill determine if it is justified:

Can I mix my own feed on the farm?As outlined in the introduction of this guide,

swine producers have several options for mixingfeed. In general, there is a trend towards takingmore of the responsibility for mixing feed. Thisgenerally lowers feed costs and increases theflexibility a producer has in mixing several differ-ent diets, but more time, labor and facilities willbe required. Probably the biggest concern is thatthe producer must now take on the added respon-sibility of quality control to ensure a properly for-mulated and mixed diet. It is difficult to determinethe size of operation for which it is profitable toassume mixing and formulation responsibilities.This will also vary with the preference and goals

of the producer. A commonly suggested tonnageat which one should consider replacing pur-chased complete feed or supplements with soy-bean meal and base mixes or premixes isbetween 500 to 750 tons per year. To calculatethe distribution of your feed costs, it is estimatedthat a sow and her pigs will require approximately7.3 tons of feed per year. More specific informa-tion on calculating feed budgets are included inthe factsheet, Growing–Finishing Pig Recommen-dations, MF2301.

By multiplying your present feed cost perphase by the projected tonnage, you can quicklysee where the bulk of your feed dollars go. This isoften a helpful analysis to determine the costcomparison between feeding programs. Compar-ing these values to your actual usage is also auseful diagnostic indicator to see if you are feed-ing the correct feed for the correct period of time,i.e., not over-feeding one phase and under-feeding another.

In addition to particle size reduction, theproducer must also be concerned about whetheror not the feed is being mixed properly, and ingre-dients must be accurately weighed. A preferredway to accomplish this is with a gravimetric scalerather than a volumetric meter. If a volumetricmeter is used, it must be recalibrated often,because bushel weights change frequently. Witha premixing system, only scaled, batch mixingoperations, not volumetric mills, should be used.

Mixers and mixing time vary considerably.Mixing times for horizontal mixers are approxi-mately 5 minutes. Worn ribbons or paddles willincrease the time necessary to adequately mix abatch of feed. Vertical mixers and on-farm grinder–mixers generally require approximately 15 minutesto mix a batch of feed. Tests have shown that over-filling mixers greatly increases the amount of timeneeded for mixing. Worn ribbons and screws willalso contribute to increased mixing times. Veryoften, manuals underestimate the amount of timenecessary for feed mixing. A mixing test is a sureway of knowing the correct mixing time for yourmixer. Mixing efficiency can be measured by tak-ing several samples of feed from one batch cycleand analyzing them for salt content. The variationbetween samples in salt content is used as anindicator of properly mixed feed (< 10%). If feed isunder-mixed, this will be more of a problem foryoung pigs because they eat only a little feed.Larger pigs, however, by virtue of their greaterfeed intake, may be less susceptible to marginallymixed feed. The sequence in which feed ingredi-ents are added to a mixer may influence mixingefficiency and feed uniformity. Ingredients shouldbe added in the following order: (1) half of thegrain; (2) protein sources, vitamins, minerals andfeed additives; (3) the remainder of the grain.

New Cost – Old Cost × 100 < % improvement inNew Cost efficiency needed to offset

added diet costs

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Can I over-mix feed?There is a common misconception that feed,

if mixed too long, can become “unmixed.” Testshave indicated that feed reaches a “steady state”of being mixed and remains at or near that pointfor an extended period of time.

How can I monitor quality control?As you assume more responsibility for mix-

ing your own feed, quality control will be vital toavoid use of inferior feed ingredients. A stringentand tough quality control program will help in thiseffort. Quality control programs will vary based onthe size of the operation and tons of feed used.However, the following is a suggested programindicating the items to check and how often.These are only suggestions, and you may checkthem more or less frequently as you see fit.

Particle size. Based on the tonnage pro-cessed per year, particle size should be checkedevery 400 to 600 tons of feed processed. If younotice whole kernels or even half kernels, thesecan be indicators of a hole in a screen or wornhammers or rollers.

Mixing Efficiency. Mixers should bechecked for proper mixing times when they arefirst installed, then updated periodically asscrews, augers and paddles become worn. Thiscan be once every year or two, depending ontonnage mixed.

Grains. Moisture content, protein, and testweight will be most critical as indicators for deter-mining grain quality. In addition, foreign materialsand presence of molds or other contaminants thatcan occur because of improper storage should benoted. A moisture tester and a blacklight (foraflotoxins) can be a practical means for on-farmtesting of grain quality. It is recommended tocheck protein content, test weight, moisture, bro-ken kernels, and foreign material twice per yearfor home raised grains and with every purchase ofoff-farm grain until consistent quality is assured.If suspect, grain should also be analyzed formolds and mycotoxins.

Soybean meal. Soybean meal is the mostcommon protein supplement used. Standards areestablished for protein, fiber and moisture. Thepurchaser is entitled to price adjustments shouldthese criteria not meet set standards. However,this price adjustment does not happen automati-cally. The producer must have the soybean mealanalyzed and request a price adjustment. Whenpurchasing a new load, request an official sampleand ask the company for a written description ofthe content. Then send the sample to a refereedanalytical laboratory for analysis. You may decideto take a duplicate sample for analysis when it isunloaded. Every load should be tested for proteinand dry matter content. In addition, calcium and

phosphorus should be tested periodically andwhenever changing suppliers. Generally, 46.5 per-cent soybean meal will have less fiber and be amore consistent protein source than 44 percentsoybean meal. Other protein sources are oftenvariable in nutrient content and should be ana-lyzed for protein content as an indicator of aminoacid content. This variation is often a hidden costof using alternative protein sources.

Dried whey, fish meal, and spray-driedblood coproducts. Because these ingredientsare often added to baby pig diets, quality isessential. We recommend specifying “ediblegrade” dried whey, “select menhaden” fish meal,and “spray-dried” blood products. These productsoften have excellent and predictable nutrient qual-ity. Research has indicated that spray-dried bloodmeal greatly improves growth performance ofearly weaned pigs compared with those fed flash-or ring-dried blood meal.

Dicalcium phosphate or monocalciumphosphate and limestone. A common problemfor producers is formulating their diet with dical-cium phosphate (21 percent Ca and 18 percentP) and buying monocalcium phosphate (18 per-cent Ca and 21 percent P). Always check feedtags and ingredient labels.

Complete supplements, base mixes, andvitamin and trace mineral premixes. Theseshould be checked periodically for certain nutrientcontent. Generally, this will include screening fortwo to four nutrients and rotating the nutrientschecked with each batch. Base mixes and pre-mixes should be checked with every change ofsupplier and then periodically, (every two to fourmonths). Base mixes should be tested for cal-cium, phosphorus, a vitamin (alternate), and tracemineral (alternate). In addition, once per year acomplete mineral analysis (Ca, P, Fe, Zn, Mn, Cu,and NaCl) is recommended. Premixes shouldalso be checked with every change of supplierand then periodically. One fat soluble (alternate)and one water soluble (alternate) vitamin shouldbe checked for vitamin premixes and one tracemineral (alternate) should be checked in tracemineral premixes. We recommend checking themore expensive nutrients, such as protein, phos-phorous, vitamin E, and riboflavin.

Fats and oils. Rancidity may be the biggestproblem with fat and oil sources. If questionable,check for free fatty acids, MIU, (moisture, impur-ities, and unsaponafiable material) and initial per-oxide value. A high quality fat source is essentialin formulating swine diets. When storing fats oroils for long periods of time, it is suggested thatthey be stabilized with an antioxidant, such asethoxyquin, BHT, or BHA.

Complete diets. If a stringent quality controlprogram is followed on all incoming ingredients

27

and processing, there should be little need tocheck the final product. However, periodicallychecking one or two of your diets on a rotationalbasis is a good way to double check your system.Check for moisture, protein, and possibly calciumand phosphorus.

The preceding items have been suggestedto monitor because they are typically the moreexpensive nutrients and are most likely not toexceed minimum requirements.

What steps should I follow toensure diet quality?1. Fill out a diet formulation sheet, including

prices and as much diet content informationas possible. Feed tags and a complete ingre-dient description should be included whenpossible. These records can provide impor-tant historical information about youroperation’s feeding program.

2. Check your calculated nutrient compositionand compare it to those suggested by KansasState University.

3. Check your diets frequently. Again, check thetonnage used by each phase of production tomake sure you are not over-feeding or under-feeding a diet. Also, continually check pricesof your diets and cost per cwt. of pork sold.

How do I take a good sample?Nutrient composition can vary within each

specific batch of feed to such a degree that chemi-cal composition can be significantly altered basedon a non-representative sample. Thus, a compos-ite sample that is representative of the completebatch mix is the key to successfully determiningnutrient concentrations. Sampling is a step-wiseprocedure that must be scrutinized heavily toensure that proper samples are obtained. First,identify the most practical method of samplingbased on the mixing system, feeding program,and the purpose of the sample. Samples taken todetermine mixing efficiency are not composite andmust be analyzed individually, whereas samplestaken to determine crude protein, calcium, aminoacids, etc., must be composite to determine aver-age composition. Thus, the first step is identifica-tion of sampling location. The following locationsare acceptable for obtaining samples.

Mixer. Samples can be taken using a graintrier/probe from separate locations within themixer; approximately 10, 1-pound samples shouldbe taken and combined into one compositesample for chemical analysis or kept separate formixing efficiency tests. The most common methodof sampling a mixer is to obtain 10 samples at thedischarge outlet while unloading the mixer. Caremust be taken to avoid sampling the initial outputas well as the final output, because these can beextremely variable.

Bulk feed. Samples should be taken duringthe loading or unloading process, and at timedintervals to ensure that a representative samplingis obtained. Samples are best obtained using anin-line, automatic sampler while moving the prod-uct to a bin or while loading a truck or car. How-ever, grab samples may be obtained whileunloading the product at the destination. Thesamples can be combined for chemical analysisor kept separate for mixing efficiency tests.

Sacked feed. Samples should be obtainedusing a bag trier/probe. Samples taken by hand,with a cup or with a dipper, are most common, butoften fail to provide the best possible sample. Ten,1⁄2-pound samples should be obtained, but devia-tion may be necessary depending upon the num-ber of sacks in the lot. The bag should be laidhorizontally and probed diagonally from end toend. From lots of 1 to 10 bags, sample all bags;and from lots greater than 11 bags, sample10 bags. Samples should be combined for chemi-cal analysis and are probably not best used formixing efficiency tests.

How do I go about bidding my feed business?Bids for the feed business of a swine opera-

tion can be conducted on complete feeds, supple-ments, base mixes, or premixes. The format forsetting up a bidding system is simple, with theproducer working with his or her nutritionist, vet-erinarian, or consultant to set up guidelines fornutrient specifications. These guidelines are thensubmitted to interested feed manufacturers whowill submit a bid for the producer to consider. It isessential that the producer follow these few stepsto ensure the fairness of the bidding procedure.Additional information can be found in the NPPCFeed Purchasing Manual.1. Write extremely clear and narrow nutrient

specifications so that products cannot bemisrepresented.

2. List all essential nutrients that must beincluded in the product to be bid on. Makesure you do not leave out any nutrients. Thisis a common mistake made by producers.Any additional nutrients or ingredients that afeed company includes in the product areextras with no nutritional or economic value.

3. List all nutrient levels per pound or ton thatmust be guaranteed in the product. Theseguaranteed levels (maximums or minimums)will be used in the quality control program. Acommon mistake is that producers will specify500 grams of choline chloride when they want500 grams of choline. In a bidding process,500 grams of choline chloride (50 percent cho-line) would leave the final diet 50 percent shorton meeting the pigs’ choline requirement.

28

4. List the desired ingredient sources for each ofthe nutrients. This is essential to provide uni-form product comparisons.

5. Include any desired mixing directions, nutrientcarriers, or information that will help the feedcompany meet the customer’s needs. This mayalso include medications and the desired levels.

6. Specify how much of a product is to be pro-vided and (or) the length of the agreement.Also include items, such as where materialsare to be delivered or picked up.

7. A quality control program must be specifiedincluding a sampling procedure and analysisprogram. In case specifications are not met,possible reimbursement schedules for thetermination of contracts should be defined.

What is an open formula?An open formula is a listing of ingredients

and nutrient concentrations supplied in a com-plete feed, protein supplement, base mix, orpremix. This information is listed on the feed tagand readily available to the producer. It can beused to compare prices based on nutrient specifi-cations to ensure that they meet the pig’s require-ments. Closed formulas do not provide nutrientspecifications, thus making it virtually impossibleto determine cost/unit nutrient or the nutrient lev-els provided in the diet.

In order to make sound economic and man-agement decisions concerning feeds and feedingredients, we strongly encourage the use ofopen formulas in swine diet formulation.

Will having feed chemically analyzedaid in diet formulation?

Yes, because individual feed ingredients willvary for the reasons explained above, testingresults will aid in diet formulation. An alphabeticallist of commercial analytical laboratories is shownin Table 12. This listing is for information only anddoes not constitute an endorsement of the labslisted nor a discredit to any lab inadvertently omit-ted from the list. It is suggested that you contactthe lab of your choice for a price list and forinstructions on size of sample, sample methods,and mailing.

What kind of variation can Iexpect in lab analyses?

It is extremely important to understand that ifa specific nutrient guarantee is not confirmed by ananalytical procedure, that this is not entirely a resultof an inferior product. Two of the largest and mostimportant sources of possible error are representa-tive sampling and analytical variation. To try tominimize possible error in analytical testing, a rep-resentative sample must be collected, subsampledand stored. Therefore, the steps and procedures forsampling outlined earlier in this section should befollowed. In addition, the Association of AmericanFeed Control Officials (AAFCO) establishes defini-tions of feed ingredients as well as minimum andmaximum nutrient levels for specific nutrients andingredients. They also establish guidelines forvariation of analysis of nutrient content within feedsor ingredients (Table 13). These can be used as areference point for determining acceptability ofingredients or finished products based on analyticaltesting. They are not intended to allow real deficien-cies or excesses of the guaranteed ingredient, norare they intended to cover sloppy work, poor sam-pling, or any deficiency in analytical or clerical pro-cedures. The acceptable variation is established byAAFCO by sending the same sample to severaldifferent labs to determine the variation betweenresults from each lab. There are several key nutri-ents that do not have established permitted analyti-cal variation allowances (such as amino acids). Forthese nutrients, the supplier and customer shouldmutually determine the acceptable allowances.Analytical variation allowances for feed medica-tions can be found in the AAFCO (1994) Officialpublication. Analytical variation is not reportedfor amino acid analysis, but variation from 20 to30 percent can be anticipated.

Composition of ingredientsIn formulating diets to meet recommended

nutrient requirements of swine, it is necessary toknow the nutrient composition of each ingredientused. Composition of ingredients commonly usedin swine diets are given in Table 14.

Individual ingredients can vary widely incomposition because of the variation in species orvariety, storage conditions, climate, soil moisture,and agronomic differences. Variations in chemicalanalytical procedure also affect values obtained.Therefore, the values given are an average andare subject to variation.

29

Table 12. Commercial Analytical Laboratories for Feed Analyses a.

Company Address Phone

Altecha LTD 731 McCall Road (Water Analysis only) Manhattan, KS 66502 785-537-9773

Colorado Analytical Laboratory P. O. Box Drawer 507Brighton, CO 80601 303-659-2313

Doty Labs 1435 Clay StreetNorth Kansas City, MO 64116 816-471-8580

Farmland Industries, Inc. Analytical Services 3705 North 139 StKansas City, KS 66109 913-721-1653

Iowa Testing Lab Highway 17 NorthP.O. Box 188Eagle Grove, IA 50533 515-448-4741

Livestock Nutrition Laboratory Services P.O. Box 1655Columbia, MO 65205 314-445-4476

Midwest Laboratories, Inc. 13611 B Street,Omaha, NE 68144-3693 402-334-7770

Peterson Lab 19 East 4th StreetBox 886Hutchinson, KS 67504-0886 316-665-5661

Scott-Pro Inc. P. O. Box 587Scott City, KS 67871 316-872-2189

Servi-Tech, Inc. Box 1415Dodge City KS 67801 316-227-7123

Servi-Tech, Inc. P.O. Box 169Hastings, NE 68901 402-463-3522

Veterinary Diagnostic Laboratory NDSU (Mycotoxins only) Box 5406

Fargo, ND 58105 701-231-8307

Woodson–Tenant Lab 3507 Delaware AvenueDes Moines, IA 50313 515-265-1461

30

Table 13. Permitted Analytical Variations (AV) Based on AAFCO Check Sample Programs.

Analysis Determination method AV%b,c Concentration range

Moisture 934.01, 930.15, 935.29 12 3–40%Protein 954.01, 976.05, 976.06, 984.13 (20/x + 2) 10–85%Fat 920.39, 954.02, 932.02 10 3–20%Fiber 962.09, 972.10 (30/x + 6) 2–30%Ash 942.05 (45/x + 3) 2–88%Pepsin digest, protein 971.09 13Total sugar as invert 925.05 12 24–37%NPN protein 941.04, 967.07 (80/x + 3) 7–60%

Calcium 927.02 (14/x + 6) .5–25%968.02 10 10–25%

12 < 10%Phosphorus 946.06, 965.17, Auto Anal. (3/x + 8) .5 –20%Salt 969.10 (7/x + 5) .5–14%Fluorine 975.08 40 ppmCobalt 968.08 40 ppmIodine 934.02, 935.14, 925.56 40 ppmCopper 968.08 25 .03–1%

30 < .03%Magnesium 968.08 20 .01–15%Iron 968.08 25 .01–5%Manganese 968.08 30 .01–17%Potassium 975.03, 925.01 15 .04–8%Zinc 968.08 20 .002–6%Selenium 969.06 25 ppmSodium a.a. 20 .2 - 4%

ICP 15 .2 - 4%

Vitamin A 974.29 30 1200–218,000 IU/lbVitamin B

12952.2 45

Riboflavin 970.65, 940.33 30 1–1500 mg/lbNiacin 961.14, 944.13 25 3–500 mg/lbPantothenic acid 945.74 25 4–190 mg/lba Method Reference from 15th Edition, AOAC Official Methods of Analysis.b x = % Guarantee (example: for a 10% Protein Guarantee AV% = (20/10 + 2) = 4% of Guarantee.

This means the low AV is 4% of 10 or .4.c Analytical Variances as derived from the AAFCO Check Sample Program. The ± signs have been

removed from the AV table. The table denotes a true analytical variation and not a tolerance. Theyapply both above and below the guarantee and are equally correct.

31

Tabl

e 14

.Fee

dstu

ff C

ompo

sitio

n Ta

ble

(As-

Fed

Bas

is)

a,b.

Cru

deC

rude

Ava

ilT

hreo

-Tr

ypto

-M

ethi

o-M

et &

M.E

.cP

rote

infa

tfib

erC

aP

hos.

phos

.Ly

sine

nine

phan

nine

cyst

ine

Fee

dstu

ffsK

cal/l

b%

%%

%%

%%

%%

%%

Alfa

lfa h

ay, s

undr

ied

800

142.

529

1.2

0.20

0.20

0.55

0.50

0.25

0.27

0.5

Alfa

lfa m

eal,

dehy

775

172.

824

1.4

0.23

0.23

0.85

0.71

0.34

0.27

0.56

Ani

mal

Pla

sma

1766

78.0

2.0

0.1

51.

71.

76.

54.

81.

4.7

03.

5B

aker

y W

aste

, deh

ydra

ted

1695

9.8

11.7

1.2

0.1

0.24

NA

d0.

310.

490.

100.

170.

34B

arle

y13

8011

.51.

75

0.1

0.34

0.10

0.40

0.36

0.15

0.16

0.37

Bee

t pul

p12

258.

80.

518

.20.

60.

09N

A0.

600.

400.

100.

010.

02B

lood

mea

l, sp

ray-

drie

d10

6086

1.2

10.

40.

300.

287.

443.

631.

051.

052.

08C

anol

a m

eal

1225

383.

811

.10.

71.

170.

192.

271.

710.

440.

681.

15C

hoic

e w

hite

gre

ase

3515

010

00

00

00

00

00

Cor

n gl

uten

mea

l17

6042

.12.

33.

80.

10.

400.

060.

781.

420.

211.

071.

73C

orn

high

lysi

ne15

758.

9N

A2.

50

0.24

0.03

0.38

0.41

0.14

NA

NA

Cor

n, y

ello

w15

508.

53.

62.

30

0.28

0.04

0.25

0.36

0.09

0.18

0.4

Cor

n oi

l33

350

100

00

00

00

00

0C

otto

nsee

d m

eal,

solv

ent

1160

41.7

1.8

10.8

0.2

1.17

0.01

1.70

1.23

0.48

0.49

1.06

Egg

pro

tein

, spr

ay-d

ried

NA

4840

0.1

0.2

0.68

NA

3.10

2.25

0.73

1.48

2.57

Fis

h m

eal,

men

hade

n15

0061

.29.

60.

95.

22.

882.

684.

742.

510.

651.

752.

33M

eat a

nd b

one

mea

l, 50

%10

3550

.99.

72.

49.

44.

583.

022.

891.

600.

280.

681.

14M

eat m

eal,

55%

1095

55.6

8.7

2.3

8.3

4.1

NA

3.09

1.78

0.38

0.73

1.41

Mill

et13

8511

.63.

56.

10

0.3

NA

0.26

0.40

0.17

0.29

NA

Mol

asse

s, c

ane

910

4.4

0.1

00.

80.

08N

AN

AN

AN

AN

AN

AO

at g

roat

s15

5015

.86.

12.

50.

10.

430.

060.

530.

440.

190.

210.

41O

ats

1240

11.8

4.7

10.7

0.1

0.34

0.07

0.40

0.38

0.15

0.18

0.37

Pea

nut m

eal,

solv

ent

1320

491.

39.

90.

30.

610.

071.

451.

370.

480.

441.

17P

oultr

y fa

t36

150

100

00

00

00

00

0R

ice

bran

1300

141.

512

.90.

11.

370.

340.

610.

530.

210.

260.

47R

ye13

6512

1.5

2.2

0.1

0.32

0.15

0.41

0.35

0.11

0.17

0.36

Ski

m m

ilk, d

ried

1620

33.3

1.1

0.2

1.3

1.02

0.93

2.54

1.57

0.43

0.90

1.35

Sor

ghum

gra

in (

milo

)14

808.

92.

82.

20

0.28

0.06

0.23

0.27

0.10

0.16

0.29

Soy

bean

mea

l, 44

%e

1460

441.

17.

30.

30.

650.

202.

851.

780.

600.

621.

32S

oybe

an m

eal,

46.5

%e

1535

46.5

0.9

3.4

0.3

0.64

0.15

3.01

1.89

0.64

0.65

1.40

Soy

bean

mea

l, 47

.5%

e15

3547

.50.

93.

40.

30.

640.

153.

081.

930.

650.

661.

43S

oybe

an m

eal,

48.0

%e

1535

48.0

0.9

3.4

0.3

0.64

0.15

3.11

1.95

0.66

0.67

1.44

Soy

bean

mea

l, 48

.5%

e15

3548

.50.

93.

40.

30.

640.

153.

141.

970.

660.

681.

45S

oybe

an o

il33

020

100

00

00

00

00

0S

unflo

wer

mea

l11

9545

.52.

911

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40.

940.

031.

681.

630.

600.

821.

55

32

Tabl

e 14

.Fee

dstu

ff C

ompo

sitio

n Ta

ble

(As-

Fed

Bas

is)

a,b (

cont

.).

Cru

deC

rude

Ava

ilT

hreo

-Tr

ypto

-M

ethi

o-M

et &

M.E

.cP

rote

infa

tfib

erC

aP

hos.

phos

.Ly

sine

nine

phan

nine

cyst

ine

Fee

dstu

ffsK

cal/l

b%

%%

%%

%%

%%

%%

Tallo

w35

800

100

00

00

00

00

0Ta

nkag

e, 6

0%98

060

NA

24.

62.

5N

A3

2.48

0.58

NA

NA

Triti

cale

1385

15.8

1.5

40.

10.

30.

140.

520.

570.

180.

210.

40W

heat

bra

n98

015

.54

100.

11.

160.

340.

560.

410.

250.

171.

43W

heat

, har

d w

inte

r14

7512

.61.

62.

60

0.37

0.19

0.4

0.37

0.17

0.22

0.52

Whe

at g

lute

n, s

pray

-drie

dN

A74

NA

NA

NA

NA

NA

1.3

2.73

0.61

2.50

NA

Whe

at m

iddl

ings

1345

16.5

4.3

7.8

0.1

0.89

0.36

0.68

0.57

0.19

0.19

0.41

Whe

at, s

oft w

inte

r14

9511

.41.

62.

30.

10.

360.

180.

360.

390.

270.

220.

58W

hey,

drie

d14

0013

.30.

80.

20.

90.

760.

730.

940.

890.

180.

190.

49Ye

ast,

brew

er’s

drie

d13

0043

.80.

93

0.1

1.36

0.91

3.23

2.06

0.51

0.66

1.18

aA

dapt

ed fr

om N

RC

(19

88),

NP

PC

Fee

d P

urch

asin

g M

anua

l, N

ebra

ska

and

Sou

th D

akot

a S

win

e N

utrit

ion

Gui

de, S

win

e N

utrit

ion

Gui

de fr

om th

e P

rairi

eS

win

e C

entr

e, a

nd N

CR

-42

Com

mitt

ee o

n S

win

e N

utrit

ion

(199

2).

bT

hese

val

ues

are

inte

nded

to b

e us

ed a

s gu

idel

ines

. Exa

ct n

utrie

nt c

onte

nt o

f an

ingr

edie

nt is

not

con

stan

t, un

less

the

ingr

edie

nt is

the

resu

lt of

a c

ontr

olle

din

dust

rial p

roce

ss (

e.g.

, vita

min

s, tr

ace

min

eral

s, c

ryst

allin

e am

ino

acid

s, e

tc.)

.c

Met

abol

izab

le e

nerg

y.d

NA

mea

ns th

ese

valu

es a

re n

ot a

vaila

ble

for

the

ingr

edie

nt.

eA

min

o ac

id le

vels

wer

e ad

apte

d fr

om N

CR

-42

Com

mitt

ee o

n S

win

e N

utrit

ion

(199

2).

33

Notes

34

Notes

35

Notes

36

Conversion Table% ppm g/ton mg/lb

0.0001 1.0 0.9 0.450.00011 1.1 1.0 0.50.001 10.0 9.1 4.550.0011 11.0 10.0 5.00.01 100.0 90.8 45.40.011 110.0 100.0 50.00.1 1000.0 908.0 454.00.11 1100.0 1000.0 500.0

Equivalents1 pound (lb) = 454 grams (g)1 mcg/lb = 2 mg/ton1 kilogram (kg) = 2.2 lb = 1000 g1 mg/lb = 2 g/ton1 g = 1000 milligrams (mg)1 mg/lb = 2.2 ppm1 mg/kg = 1 part/million (ppm)1 mg = 1,000 micrograms (mcg)

Metric System—Mass Conversion

To Convertmg/g to mg/lb — multiply by 454mcg/g to mg/g — divide by 1,000mg/lb to mcg/g — divide by 0.454mg/lb to ppm — multiply by 2.2g/lb to % — divide by 4.54% to g/lb — multiply by 4.54

Robert D. GoodbandExtension Specialist, Swine

Mike D. TokachExtension Specialist, Livestock Production and Management, NE

Steve S. DritzFood Animal Health and Management Center

Jim L. NelssenExtension Specialist, Swine

Kansas State University Agricultural Experiment Station and Cooperative Extension Service

MF2298 October 1997

It is the policy of Kansas State University Agricultural Experiment Station and Cooperative Extension Service that all persons shall haveequal opportunity and access to its educational programs, services, activities, and materials without regard to race, color, religion, nationalorigin, sex, age or disability. Kansas State University is an equal opportunity organization. Issued in furtherance of Cooperative ExtensionWork, Acts of May 8 and June 30, 1914, as amended. Kansas State University, County Extension Councils, Extension Districts, and UnitedStates Department of Agriculture Cooperating, Marc A. Johnson, Director. File code: Animals Sciences and Industry

Brand names appearing in this publication are for product identification purposes only. No endorsement is intended,nor is criticism implied of similar products not mentioned.

This publication is one of a series of six: (Premix, Base Mix and Starter Diet Recommendations for Swine, MF2299;Starter Pig Recommendations, MF2300; Growing–Finishing Pig Recommendations, MF2301; Breeding Herd Recommendations for Swine,

MF2302; Feed Additive Guidelines for Swine, MF2303).

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Contents of this publication may be freely reproduced for educational purposes. All other rights reserved. In each case, credit Steve S. Dritz,Robert D. Goodband, Jim L. Nelssen, Mike D. Tokach, Swine Nutrition Guide, Kansas State University, October 1997.