FEEDS & FEED PROCESSING MANAGEMENT

By

David R. Hawkins

Michigan State University

DRY MATTER INTAKE

• Many feedlot managers anticipate animal performance by monitoring dry matter intake (DMI).

• As cattle get older and heavier, daily DMI expressed as a % of body weight declines.

• A 400 lb. animal will eat about 2.8% of its body weight as DMI daily, while DMI for a 1200 lb. animal may be only 2.0% or less.

FACTORS REDUCING DMI

• Stale or moldy feeds will reduce daily DMI.

• Wide variation in ration dry matter will reduce DMI.

• Foreign substances such as manure, snow, large stems, etc.

• High salt content will reduce DMI.

SELF FEEDING BEEF CATTLE

• Cattle are not as well adapted to self feeding as swine or poultry.

• Self feeding usually results in slightly lower DMI than a fence line feed-bunk system.

• Requires ration that is dry (<14% moisture).• Ration must stay uniformly mixed.• Can result in lower labor costs, if well

managed.

COMMON GOALS of FEED PROCESSING

1. Improved feed conversion or efficiency.

2. Increased feed intake and faster ADG.

3. Improved carcass quality and/or yield grade

4. Reduction in feed waste.

5. Lower transportation and storage costs.

6. Reduced labor costs due to increased mechanization.

COMMON GOALS OF FEED PROCESSING

7. Reduced energy costs of processing (drying versus ensiling).

8. Reduced harvest costs (i.e. high moisture corn).

9. Improved cattle health by reduction in digestive disorders (founder, bloat & acidosis).

PRIMARY ENERGY FEEDS IN U.S. CATTLE FEEDING

• Corn - Midwest and High Plains• Milo - High Plains• Barley - Northwest• Corn silage - Adequate energy to finish cattle

but low CP• Alfalfa hay or haylage - High CP but too low

in energy to generate acceptable gains unless grain is added to ration

DRY PROCESSING of GRAINS

• Grinding - increases surface area for bacterial digestion.

• Dry rolling, crimping or cracking - cattle prefer a coarse grind.

• Popping - Hot air for 30 sec. + rolling.

• Micronizing - Infrared heat for 3 min. + rolling

DRY PROCESSING of GRAINS

• Roasting - Heat for a short period of time.

• Pelleting - grind & force through a die.

• Extruding - Pressure screw forces grain through a die.

WET PROCESSING of GRAIN

• Steam rolling - grain exposed to steam for 3 to 5 min. and then rolled.

• Steam flaking - steam for 15 to 30 minutes. Water content increases to 20%, + rolling.

• High moisture grain - harvested at 20% to 35% moisture & ensiled.

• Acid preservation of high moisture grain. Acetic or proprionic acid retards spoilage.

HEAT PROCESSING of GRAIN

• 10% to 50% of starch in kernal changes to a gelatin.

• Rumen VFA profile changes so that ADG improves.

• Feed consumption may decrease slightly.

• Net result is a small improvement in ADG and a larger improvement in feed efficiency.

• Greater effect on milo than on corn.

SUMMARY of CORN SILAGE RESEARCH

• Corn varieties that produce maximum grain yields result in maximum dry matter intake.

• Corn silage is typically 50% grain and 50% roughage on a dry matter basis.

• Cattle performance improves as grain content of ration increases up to 80% added grain. (This is a 90% concentrate ration).

• Cattle need a minimal level of roughage to maintain rumen function.

CORN SILAGE RESEARCH (continued)

• Maximum DM yields and DMI occur when plant is harvested just prior to dough dent stage (27% to 34% plant dry matter).

• NPN addition also works best at this plant dry matter level.

• Fine chopping (1/4 to 3/8 in. cut) allows greater compaction and promotes a more desirable fermentation.

CORN SILAGE FEEDING SYSTEMS

• Corn silage is more valuable for calves than for yearlings.

• When corn silage is fed, it appears to be best in a two phase system (high roughage grower phase followed by a high grain finishing phase).

• Silage rations are more effectively used for smaller framed British type cattle than for larger framed dairy or continental types.

CARCASS RESULTS FROM CORN SILAGE RATIONS

• Cattle fed high corn silage rations need to be fed to heavier weights (50 to 100 lbs.) to achieve the same marbling levels as high grain fed cattle of similar genetics.

• Cattle fed high corn silage rations tend to have less total fat (desirable yield grades).

• Cattle fed high corn silage rations gain slower & have more days on feed (higher non feed costs or yardage).

NPN ADDITION TO CORN SILAGE

• Do not use high levels of NPN for calves under 600 lbs.

• Adding NPN at ensiling time gives superior cattle performance as compared to adding the same level of NPN at feeding time.

• NPN combines with VFAs produced during fermentation to form stable compounds like ammonium acetate, ammonium lactate, etc.

UREA ADDITION TO CORN SILAGE

• Urea is 45% N (45 x 6.25 = 281% CPE).

• When added at ensiling time, ADG is similar to SBM supplemented ration but feed efficiency is about 3% better than SBM supplemented rations.

• When added at feeding time, both ADG and FE are 3% lower than with SBM rations.

UREA ADDITION TO CORN SILAGE

1. Assume we have 35% dm corn plant that analyzes 8% CP on a dry matter basis.

2. We desire a 13% CP silage after fermentation.

3. How much urea must we add at ensiling time per ton of chopped corn plant?

UREA ADDITION TO CORN SILAGE (continued)

2000# of corn plant x .35 = 700# of dm

700# x .08 = 56# of CP

We need 700# x .13 = 91# of CP to meet goal

91# - 56# = 35# of CP needed

1# of urea contains 2.81# of CPE nitrogen

35#/2.81 = 12.45# of urea to be added to each ton of chopped corn plant

OTHER NPN SOURCES FOR CORN SILAGE ADDITION

1. Ammonia-mineral (13.6%N, 85%CPE, 10% loss due to volatilization).

2. Aqueous ammonia (22%N, 137%CPE, 10% loss due to volatilization).

3. Anhydrous Ammonia (82%N, 512%CPE, 25% loss due to volatilization).

ADG is 4% less and 3% more feed is required than with SBM supplemented rations, but still may be very cost effective.

ROUGHAGE SOURCES FOR FEEDLOT CATTLE

• Cattle require minimal levels of roughage to maintain rumen function.

• Low levels of roughage will improve DMI and consequently ADG.

• Per unit of energy, roughages are more expensive than grain.

• Roughages tend to be difficult to mechanize and more expensive to transport than grain.

ROUGHAGE GUIDELINES FOR FINISHING RATIONS

• Dry whole corn ration - at least 5% roughage (10% of dm, if corn silage)

• Dry rolled corn ration - 10 to 15% roughage (20 to 30% of dm, if corn silage)

• High moisture corn ration - 10 to 15% roughage (20 to 30% of dm, if corn silage)

• Ionophores have permitted us to feed higher concentrate rations with fewer digestive problems.

BYPRODUCT OR COPRODUCT FEEDS

• Michigan has a very diverse agriculture with many crops that yield byproducts during processing.

• Examples include: cull potatoes, cannery products, brewery byproducts, cull cookies, cull beans, fruit pulp, animal tallow, etc.

• Many of these can be utilized in feedlot rations if they are cost effective per unit of energy.

GUIDELINES FOR FEEDING UNUSUAL FEEDS

• In general, keep these unusual feeds at less than 25% of total ration dry matter.

• Fat levels above 8% of ration dry matter will interfere with normal metabolism of rumen bacteria and protozoa.

• Monitor cattle closely for digestive disturbances including diarrhea, bloat, acidosis and/or founder.