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Dairy Cattle Nutrition – The Basics
Dr. L. E. ChaseDepartment of Animal Science
Cornell University
Today’s Dairy CowThe dairy cow is a marvel as a
biological manufacturing plantThe “average” New York dairy
cow produced 20,071 lbs. of milk per lactation in 2009
The “average” New York dairy cow produced 10,885 lbs. of milk per lactation in 1970
This is an 84% increase!
Today’s Dairy Cow - 2We have a number of herds in NY
with herd average milk production > 30,000 lbs/cow
What is the biological limit to milk production?
How can an individual cow in a herd produce > 200 lbs of milk per day when housed in a group fed a ration balanced for 85 lbs. of milk?
Current World Record - HolsteinEver-Green-View My 1326-ET3x, 365 days = 72,170 lbs milkAverage = 198 lbs/day!
What About Jersey’s?World record – 2007Mainstream Barkly Jubilee2x, 365 days = 49,250 lbs. milk4.6% fat, 3.3% milk true proteinAverage of 135 lbs. milk/day!Was on supplemented rotational
grazing for part of the record
World Lifetime Milk Production Record Cow
8/2004 = 442,690 lbs milk
> 52,000 Gallons!!!!
Milk -- 100 lbs (13 lbs of dry matter)- 4.9 lbs. of lactose (sugar)- 3.6 lbs of milk fat- 3.1 lbs. of milk true protein
Manure - - 190 lbs of total manure
- 60 – 70 lbs of urine- 120 -130 lbs fecal material
What Does a Cow Producing 100 lbs. of Milk Excrete/Day?
What Does a Cow producing 100 lbs. of Milk Need to Make Each Day? - 7 – 8 lbs of glucose (sugar)- 3 – 4 lbs. of microbial protein- 2 – 2.5 lbs of absorbed amino
acids
How Much Does This Cow Eat & Drink?55 – 60 lbs. of feed dry matter
intake - 120 – 130 lbs of wet feed - Assumes ration is 45% dry matter
Drinks 30 – 35 gallons of water
Why is DMI Important?Must be a package size that the
cow can be expected to consumeRelated directly to potential milk
production, feed cost and PROFITEssential if rations are formulated
on a nutrient density basisCan’t do problem solving without
DMI
What Controls DMI?
Ration Energy Content
LowHigh
Intake
Energy
DM
Factors Affecting Dry Matter IntakeCow FactorsMilk Milk Solids SizeMaturityDays in MilkGeneticsTransition InsultsMastitis Status
Forage FactorsMaturityTexture/Particle DistributionCondition - moldCondition - pHCondition - fermentation
Environmental FactorsAir Quality - ventilation Ambient TemperatureRelative HumidityHaircoat ConditionAccess to FeedSocial OverheadAccess to StallManger/Bunk SurfaceStall ComfortLightingbSTRation Intended vs. Utilized*
Concentrate FactorsComplement with ForageTextureCondition - moldCondition - freshness
People FactorsWho is responsible for every other factor listed above?!
Factors Which Influence DMI
45%
22%
6%
17%
10%
MilkFeedBCSBWEnv.
High Producing Dairy HerdsDo they attain high levels of milk
production by increasing ration nutrient density or do they have higher levels of DMI?
Monitoring DMIUse scales that work + moisture
testerKnow what is fed, refused,
consumedHow many cows are in the
group?Graph intake & milk productionCalculate “actual” versus
“predicted” grain disappearance rate
What Nutrients Does A Cow Need?WaterProteinCarbohydratesLipids/fatsMineralsVitaminsEnergy???
WaterNutrient required in the largest
quantity per dayMilk is about 87% waterThe cow’s body is about 56 to
81% water (784 to 1134 lbs. for a 1400 lb. cow)
Predicted Daily Water Intake for Lactating Cows
05
1015202530354045
Gallons
40 60 80 100 120 140
Milk, lbs/day
45 F
85 F
Murphy et. al., 1983
Intakes of Other Animal Groups
Group Gallons/ day
Dry cows 5 – 10
Heifers (>5 months) 5 – 10
Calves (< 5 months) 1 - 5
Is This Clean Water?
Would You Drink this Water?
Would You Drink this Water?
Nutrient
Definition:◦ A dietary essential for one or more species of
animalAll animals do not require the same
nutrientsLaboratory analyses determines the
nutrients we feed◦ Fiber vs ADF
Ruminants have simpler dietary nutrient requirements because many are supplied by the rumen bugs
Nutrient Use and EfficiencyThe first use of any nutrient is
meet the maintenance requirement of the animal
This is a fixed cost related to body weight and
EnergyNot a nutrientObtained from several sources
◦Carbohydrates - CHO◦Fats - 2.25 times the energy◦Proteins – Via deamination
Net Energy MeasuresEnergy level in a feed or ration
can be expressed in a variety of ways.
TDN – Total digestible nutrientsNFE – Nitrogen free extractNet Energy Basis
◦NEM ◦NEL ◦NEG
Expressed as Megacalories of Energy - Mcals
Nutrient CategoriesProteinCarbohydratesLipids/FatsMineralsVitaminsWater
Chemical Analysis Scheme
Protein is Required to:1. Principle component of body tissues2. Enhance feed intake and energy use
Enzymes
3. Supply N to the rumen microbes ◦ Ammonia, Amino acids, Peptides
4. Supply amino acids for synthesis of:◦ Milk protein ◦ Tissue protein ◦ Enzymes, hormones etc.
Protein Terminology
Intake Protein◦IP - What the cow eats
Crude Protein◦Calculated from Nitrogen content of
feed◦Proteins are 16% N◦Multiply N content of feed by 6.25
(100/16)◦Measure of the total protein in a feed
Both true and NPN◦Measured as a % of the dry matter
Protein Terminology
Rumen Degradable Protein ◦ Broken down in rumen and used by the
rumen bugs( RDP)
◦ Soluble Protein (SIP) is the portion of the RDP that is rapidly broken down in the rumen
Rumen Undegradable Protein◦ Not broken down in rumen◦ Also referred to as bypass protein
( RUP)
Protein Terminology
Microbial Protein◦ Refers to protein produced by the bugs in
the rumen ◦ Microbial protein is important because it
supplies ~50% of cow’s total protein requirement
◦ Microbial protein is much higher quality protein than the feed components from which it was produced
◦ As a result you don't have to worry too much about the amino acid (AA) content of the diet or providing the essential AA in diet.
◦ Rumen microbes use protein and degradable energy sources for the production of microbial protein
Amino Acids
Essential and Nonessential◦ Nonessential - synthesized by body◦ Essential - 10 Essential AA’s
Necessary for the animal Must come from diet
Not a concern in most ruminant diets because essential AA’s are synthesized by rumen bugs as microbial protein is produced
However in higher producing animals we see a response to adding certain essential AA’s such as lysine or methionine
Carbohydrates
Major source of energy for cattleMakes up more than 65% of DM in feedsBroken down in rumen to VFA’s, methane,
carbon dioxide and waterTwo types
◦ Structural and NonstructuralTremendous differences in the speed with
which structural and nonstructural breakdown in the rumen. ◦ Structural Slow; Nonstructural - Rapid
Compatible combination important for good rumen digestion
Plant Carbohydrate Fractions(Hall, 2003)
Carbohydrates
NFC Sugars, starch, pectin
Highly RuminallyAvailable
Effective NDF
Physical NDFDigestible NDF
Microbial Digestion
StimulatesChewing
Saliva secretion: 80 gal/d 7 lb Na bicarb 3 lb phosphate buffers
Buffering agents:NH3, forage, protein
Acid Productionfrom VFAs
NDFiber
Carbohydrate Digestion Dynamics
, starch
(sugars)
Physical & Chemical Fiber Recommendations
Chemical NDF◦ 28-32% of ration DM◦ Minimum ~25% (NRC,
2001)◦ 1.2% of body weight
as total NDF intake 1350-lb BW x 0.012 =
16.2 lb NDF intake/d Realistic upper limit on
NDF intake/day Fermentability of NDF
Physical NDF ◦ 550-600 min of
rumination/day◦ ~60% of resting
cows should be ruminating
◦ Rumen pH >5.8◦ ~5-8% >19 mm
Penn State PS◦ peNDF >21% of DM
Fats
Also known as Ether ExtractHighest energy per lbChemical structure
◦ Fatty acids - Hydrocarbon chains ◦ Glycerol
Majority absorbed in small intestines ◦ Few converted to VFA’s
Too much fat in the diet inhibits rumen digestion of cellulose ◦ Fatty Acids inhibit bacteria ◦ Coats fiber to prevent breakdown
Feeding Fat
Fat is 225% the energy of CHO or protein ◦ Good way to boost the NEL of a diet ◦ When physically can’t get anymore energy
into the diet with grains and by products Low heat increment so it is good to add in
hot weather Inhibits fiber digestionFats provide energy for the dairy cow but
not the rumen bugs (rumen bugs need carbohydrate energy)
MineralsMineral required by dairy cattle
◦ Calcium for milk production◦ Mineral supplements usually nearly 100 %
DM◦ Minerals, vitamins and other additives take
up space or DM in the ration Provide little or none of the major nutrients.
◦ When balancing rations leave about 1 – 2 lb of space for these supplements. i.e. If DMI is estimated to be 50lb/day, balance
the ration to meet the NEL, CP, ADF, NDF, and NSC in 49 lb of DM leaving one pound for all the minerals and vitamins etc. that need to be added
Macro MineralsGrams/cow/dayCalciumPhosphorusPotassiumMagnesiumSulfurSodiumChloride
Micro (trace) mineralsMilligrams/cow/dayIronZincManganeseCopperCobaltIodineSelenium
VitaminsWater soluble - B's & C
Fat soluble - A,D,E & KBugs in the rumen
◦ No requirement for any of the water soluble vitamins.
◦ The bugs manufacture their own B vitamins.
◦ Only supplement the A, D, & E◦ However as milk production increases we
balance the ration for more feed to bypass digestion. We are finding that supplementation of niacin (B3) and others may have a positive affect on animal performance.
Summary