FEEDS & FEED PROCESSING
MANAGEMENT
By
David R. Hawkins
Michigan State University
COMMON GOALS of FEED
PROCESSING
1. Increased feed intake and digestibility
2. Improved feed conversion or efficiency
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. Inactivating anti-nutritional factors or specific
growth inhibitors
10. Improved cattle health by reduction in digestive
disorders (founder, bloat & acidosis).
Feed Stuff
Inhibitor
Cottonseed Meal Gossypol: Cyclopropane
fatty acids; Phytate
Soybean Meal
Trypsin inhibitor
Linseed Meal
Crystalline water-soluble
substance
Raw Fish
Thiaminase
Alfalfa Meal
Saponins; pectin methyl
esterase
Rye
5-N-alkyl resorcinols
Sweet Clover
Dicoumarol
Wheat Germ
Unidentified
Rapeseed
Isothiocyanate; thyroactive
materials
Deactivation Process
Add iron salts; rupture
pigment gland
Heat, autoclaving
Water treatment
Heat
Limit amount fed
Limit amount fed
Heat
Heat
Heat
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.
Effects of Processing on the Nutritional Value of
Feeds
• HEAT TREATMENT
˗ to dry certain plant products and to improve the quality
of pelleted feeds
˗ employed in the extraction processes to remove oil from
some oilseeds.
˗ destroying the trypsin inhibitor which is naturally
present in soybean
˗ increases the nutritional value and improves digestibility
of cereal grains by gelatinizing starches
˗ steam pelleting results in improved pellet durability and
a reduced amount of fines in the finished product.
Effects of Processing on the Nutritional Value of
Feeds
• GRINDING
˗ Grinding may increase the nutritional value of feeds by
reducing the particle size
˗ Increasing intake
˗ Increasing the surface area of the ingested feed and
facilitating digestion
˗ Grinding process adds metals to feeds from the grinding
machinery and can prevent a micromineral Fe, Zn, Cu,
Mn, and Na.
Effects of Processing on the Nutritional Value of
Feeds
• PELLETING AND CRUMBLING
˗ compacts the mixed feed ingredients and increases
nutrient density and bulk density
˗ improves palatability or acceptability and digestibility
of feeds
˗ heat applied during compaction of the pellet may also
improve digestibility and destroy thermolabile toxic
factors
˗ improves the use of low density, bulky, unpalatable
feeds that might not otherwise be practical to use
Effects of Processing on the Nutritional Value of
Feeds
• EFFECT OF PROCESSING ON MOULDS,
SALMONELLA, AND OTHER HARMFUL
SUBSTANCES
˗ Aflatoxins, produced on some feeds by Aspergillus flavus,
are not inactivated by normal pelleting procedures
˗ Prevention of mould growth is the best means to avoid
contamination.
˗ Removal and disposal of mould-damaged material is
essential
˗ Feeds sometimes contaminated by aflatoxins, such as corn,
peanut meal, cottonseed meal, copra, and fish meal
Effects of Processing on the Nutritional Value of
Feeds
• EFFECT OF PROCESSING ON MOULDS,
SALMONELLA, AND OTHER HARMFUL
SUBSTANCES
˗ Salmonella is killed by pelleting.
˗ Meat meal is a feed ingredient that should be routinely
monitored for the presence of salmonella; proper sanitation
procedures will reduce the incidence of contamination
Effects of Processing on the Nutritional Value of
Feeds
• EFFECT OF PROCESSING ON THE AVAILABILITY
AND NUTRITIONAL VALUE OF VITAMINS
˗ Prolonged heat treatment can destroy the fat soluble and the
water soluble vitamins
˗ Such heat treatment can occur during the drying of protein
supplements of plant and animal origin.
˗ For example, meat and bone meal contains little or no
thiamine as a result of processing.
˗ The water soluble B vitamins are removed during the
processing of fish into fish meal.
˗ If insufficient anti-oxidants are present in the feed, pelleting
may destroy Vitamins A, E, and K
Effects of Processing on the Nutritional Value of
Feeds
˗ Certain trace minerals act as pro-oxidants in feeds and can
hasten the oxidative destruction of Vitamins A, D, and E.
Manganese and iron are examples of such minerals.
˗ Grinding , coarse wheat flour grinding lose less Vitamin E
than fine grinders
˗ Solvent extraction of soybean meal results in the removal of
some of the Vitamins E and K
˗ Germinated wheat may have a Vitamin E level as low as 30
percent of ungerminated wheat.
Effects of Processing on the Nutritional Value of
Feeds
• EFFECT OF PROCESSING ON THE AVAILABILITY
AND NUTRITIONAL VALUE OF TRACE MINERAL
ELEMENTS
˗ Generally, the availability of minerals is not affected by
processing.
˗ The availability of zinc is sometimes enhanced by addition
of the chelate EDTA.
˗ Pelleting and crumbling do not affect trace mineral levels in
feed