This presentation deals with various feed processing methods with their advantages and disadvantages for particular feedstuffs.

1. FEED PROCESSING
prepared by- Bijay Shrestha
M.Sc. (Animal Nutrition), AFU, Rampur

2. Introduction to FEED PROCESSING
• Feeds- important and most deciding factor in animal
production
– In ruminants, the feeds represent 50% or more of the total
production costs and
– in non-ruminants, the feed cost may be 80% or more of total
production costs
• Any sort of wastage of feed- affects the economical and
efficient animal production
• Modification in terms of physical, chemical properties of the
feed that leads to ease and efficient feeding behavior of
animal
• Feed processing- not only enhance the feed quality, it also
minimizes the loss during feeding

3. Introduction to FEED PROCESSING
• Feed preparatory methods that are used for swine and
poultry are relatively simple and few as compared to the
variety of methods available for ruminant feeds
• Our discussion deals with
– Grain processing methods
– Feed processing for Non ruminants
– Feed processing for Ruminants
– Feed mixing
– Dry forage and roughage processing for Ruminants

4. COMMON GOALS of FEED PROCESSING
• Improved feed conversion or efficiency.
• Increased feed intake and faster average daily gain.
• Improved carcass quality and/or yield grade
• Reduction in feed waste.
• Lower transportation and storage costs.
• Reduced labor costs due to increased mechanization.
• Reduced energy costs of processing (drying versus
ensiling).
• Reduced harvest costs (i.e. high moisture corn).
• Improved cattle health by reduction in digestive disorders
(founder, bloat & acidosis).

5. GRAIN PROCESSING METHODS
• Grain processing methods- divided into DRY and WET
processes or into COLD and HOT processing.
• Heat- essential part of some methods, but not utilized at all
in others.
• Likewise, added moisture- essential in some methods but
may be detrimental in others.
Examples of milo (grain, sorghum) processed in different ways as shown in Fig.

6. 1. HOT PROCESSING METHODS
• Process that require the heat to develop final feed product
• Include- Stem Rolling, Steam Flaking, Popping, Micronizing,
Roasting, Pelleting, and Extruding.
• Excess destroys nutrients – Protein, vitamins
• When done properly – increases nutrient availability.
– Destroys trypsin inhibitor in Soybeans
– Improves rate and efficiency of gains through partial
gelatinization of protein.
– Improves availability of fats and AA. Increases ME

7. A. STEM ROLLING, STEAM FLAKING
STEM ROLLING
• Kills weed seeds in feed grains
• Expose grain to steam for 3-5 minutes before rolling
• Does not improve feed efficiency over grinding
• Increases palatability and animal acceptance
• Allow production of larger particles and fewer fines
• May add up to 6 % moisture to grain
STEAM FLAKING
• Modification of steam rolling by increasing the amount of
time steam is applied or by the amount of pressure.
• Milo responds the best along with maize and barley

8. • Grain is subjected to high-moisture steam for a sufficient
time to raise the water content to 18-20%,
• Preferred method for horses. – Fluffy - produces fewer
digestive problems
• Flaking influences the density of the feed
• Results depend on: Steaming time, temperature, grain
moisture, roller size and tolerance, processing rate, type
and variety of grain.

9. B. PELLETING
• Accomplished by grinding the feed ingredients and then
forcing them through a die
• Compacting and forcing through dies
– Facilitates mechanization
– Eliminates fines. Increases palatability
– Alleviates separation of ingredients and sorting (protein
concentrates- reduces loss even when fed on ground or
windy areas)
– Increases feed density
• Reduce storage space, Transportation costs
• Different shapes, diameters, lengths, and degree of
hardness

10. C. POPPING AND MICRONIZING
• Popping- By the action of dry heat, causing a sudden
expansion that ruptures the endosperm of the seed
• Popping- Hot air for 30 seconds + Rolling
• Which increase rumen and intestinal starch utilization but
results in a low density feed
• Consequently, feeds usually rolled before feeding to
reduce bulk.
• Micronizing- essentially the same as popping, except that
is provided in the form of infrared energy.
• Micronizing = Infrared heat for 3minutes + Rolling

11. D. EXTRUDING
• Feeds for pets- extruded
• Prepared by passing the grain or mixtures through a
machine with a spiral screw that forces the grain through a
tapered head
• Grain- ground and heated, and mixed with other
ingredients, producing a ribbon-like product
• Gelatinization during extruding, starch becomes soluble
and absorbs large quantities of water.

12. E. SPRAYING FEEDS WITH MOLASSES, FAT, etc
• Spraying of molasses and fats onto the surface of feeds
– to improve palatability and reduce dustiness.
– increases the energy density of the feed
– and improves the ease of mechanical handling and
– serves as a lubricant in augar, pipes, and storage bins.
• Other liquids that can be added to feeds during mixing
– as a means of providing micronutrients, amino acids, flavor
compounds, and mold inhibitors

13. 2. COLD PROCESSING METHODS
• Process where the heat is not involved for the processing
of the feed.
• Methods (or machinery) used for cold processing include
– Roller mills(rolling), Hammer mills (Grinding), Soaking,
Reconstitution, Ensiling at High Moisture Content, and
Preservation with Added Chemicals.
A. Roller mills (Rolling)
• Act on grain by compressing it between two smooth or
corrugated rollers that can be screwed together to produce
smaller and smaller particles.
• With grains such as corn, wheat, or milo, the product can
range in size from cracked grain to a rather fine powder.

14. A. Roller mills (Rolling)
• With the coarse grains- barley and oats- usually corrugated
rollers are used and the product may range in size from a
flattened seed to a finely ground product, but not the hulls
• Corrugated rollers- create a product called crimped grain
e.g., crimped oats.
• Produce a less dusty feed than that produced by hammer
mills.
• Physical texture- very acceptable- if the feed is not ground
too finely
• Roller mills- not used with roughages

15. B. HAMMER MILLS (GRINDING)
• With the aid of rotating metal bars (hammers) that blow the
ground product through a metal screen
• Size of the product- controlled by changing the screen size
• Grind anything from a coarse roughage to any type of
grain,
• Product size will vary
from particles of a size
similar to cracked grain
to that of a fine powder.
• Sig. amount of dust lost in the process and the finished
product- usually dustier than that with a roller mill.

16. C. SOAKED GRAIN
• Long history of feeding- grain soaked for 12-24 hour in
water
• The soaking sometimes with heat, softens the grain, which
swells during the process, making a palatable product that
should be rolled before using in finishing rations.
• Space requirements, problems in handling, and potential
sourcing have discouraged large-scale use.
D. RECONSTITUTION
• Like soaking- adding water to mature dry grain to raise
moisture content to 25-30% & storage of the wet grain in
an oxygen-limiting silo for 14-21 days prior to feeding
• works well with sorghum in particular

17. E. HIGH-MOISTURE GRAIN
• High moisture grain- harvested at a high moisture content
(25-30%) and stored in a silo to preserve the grain
• The grain- ground before ensiling or ground or rolled
before feeding
• Useful procedure- when the weather condition do not allow
normal drying in the field
• No need to dry the grain artificially
• Storage costs- relatively high, but high-moisture grains-
good feedlot results
• Improvement of feed conversion
• Ensiled wet grains- not easily sold or transported as grains
not preserved for that purpose

18. F. ACID PRESERVATION OF HIGH-MOISTURE GRAIN
• Higher fuel costs- increased interest in eliminating artificial
drying of freshly harvested cereal grains
• Use of acids to preserve high-moisture grains found
effective because of research
– With barley or corn for pigs and
– With corn or sorghum for beef cattle
• Thorough mixing of 1 to 1.5% propionic acid, mixtures of
acetic-propionic acid or formic-propionic acid into high
moisture (20-30%)
– whole corn or other cereal grains- retards molding and
spoilage without affecting animal performance appreciably,
compared with that obtained with dried grains

19. FEED PROCESSING FOR NONRUMINANTS
I. Swine and Poultry
• Grinding and pelleting- most common for swine and poultry
• Grinding (medium to moderately fine texture)- better
performance than when grains are finely ground.
• Feed particles of different ingredients- similar size
– animals do not sort out the coarse particles and leave the
fines.
• Digestibility of grains by swine- improved by grinding, and
finely ground (0.16cm screen size)- better compared with
coarse grinding (1.27cm screen or larger) in a hammer
mill.
• Finely ground feed- increased incidence of stomach ulcers

20. I. Swine and Poultry
• Pelleting- (3-5%) improvement in rate of weight gain
• Efficiency- improved (5-10%) sometimes because of less
feed wastage with pellets
• A common practice for poultry-
– to pellet meal diets,
– then roll them, and
– screen out fines, producing a product called crumbles
• Texture of crumbles- well liked, compared with that of
pellets particularly if the pellets are quite hard
• Birds fed pellets- exhibit more cannibalism than those
given feed in mash form

21. II. OTHER ANIMALS
HORSES
• Processing of horse feed- to avoid dust and mold
• Horse feeds- rolled or coarsely cracked grains with liberal
amounts of molasses to avoid problems with dust.
• Some pelleted or cubed hays are fed- small percentage of
the total forage fed to horses
• Cubed hays- problems with choking.
RABBITS
• Fed pelleted, mixed feeds and/or long roughages.
• Commercial growers- pelleted feeds because of
convenience and to reduce waste.

22. II. OTHER ANIMALS
• A substantial amount of pet food- either pelleted or
processed through extruders
• Such processing methods- alter the physical form as well
as the nutritive value the feed by the heat generated in the
process

23. GRAIN PROCESSING FOR RUMINANTS
• Grain processing- to improve digestibility and efficiency of
utilization
• Improvement in grain feeds- obtained by various means
that break up the hull or waxy seed coat and improve
digestibility of starch in the endosperm.
• For a method to be effective, it must (a) reduce wastage,
(b) increase consumption and rate of gain or (c) be utilized
more efficiently.
• Grain (or roughage) is expected to give greater returns per
unit of cost when feed intake is high.
• Animals on a maintenance diet normally would not be fed
much grain and any improvement in efficiency normally
would not return the added cost of processing.

24. I. FEED PROCESSING FOR DAIRY COWS
• Feed processing- different responses in dairy cows than for
growing or finishing cattle or lambs
• Generally, feeding lactating cows’ high-grain rations,
(pelleted form)- results in reduced rumen acetate to
propionate ratios and lower milkfat percentages
• Total milkfat production may not be decreased because
feedstuffs that are capable of causing low milkfat may also
stimulate increased total milk production.
• Lactating cows- fed concentrates (coarsely ground or
steam rolled grains)
• Pelleted feeds- in milking parlors in many operations
Cows- eat more pellets in short period of time while being
milked

25. I. FEED PROCESSING FOR DAIRY COWS
• Pelleting- avoids some of the dust
• Some dairy farmers- utilize ground and ensiled high-
moisture grains, particularly maize

26. II. GRAIN PROCESSING FOR SHEEP
• Processed grains fed to sheep- fewer advantages
• Diet sorting and wastage- reduced due to pelleting
• Sheep chew grains (with the possible exception of
sorghum) well enough- no requirement of feed processing
• Not a common practice to feed as much grain to sheep as
to cattle, so any possible benefits of processing- limited
• Common practice to pellet finishing rations- allows greater
use of forages or roughages

27. DRY FORAGE AND ROUGHAGE PROCESSING FOR RUMINANT
A. Baled Dry Forage and Roughage
• Baling- a large bundle or package of feeds prepared from
dry forage and roughage (sold or transported some
distance)
• Baling- considerable advantage over loose hay stacked in
the field or roughage in other less dense forms
• Considerable waste may occur in feeding- depending on
how it is fed (feed bunks, on the ground) and on the level
of feeding.
• High loss of nutrients occurs in feeding baled hay- feeding
dairy animals
• Dehydrated bagged alfalfa, feeding horses and ruminants

28. B. CHOPPED AND GROUND FORAGES AND ROUGHAGE
• Chopping or grinding of forages and roughage
– allows easier handling by some mechanical equipment,
– tends to provide a more uniform product for consumption
– usually reduces feed refusals and waste
• Additional expense- by grinding- loss of part of the feed in
the process of grinding in hammer mills
• Can be reduced by spraying fat before grinding
• Ground hays- dusty and may not be consumed readily.
Adding molasses, fat, or water- improves intake.
• Chopping- more desirable than grinding, but chopped hay
does not blend in feeds as ground hay.

29. C. PELLETING
• Pelleted forages- readily consumed by ruminants
• Forages such as long hay- ground before pelleting;
– Slow and costly process compared to similar treatment of
grains
• Pelleting- increase in performance for low-quality forages
and roughages
• Pelleted forages and roughages- metabolized somewhat
differently;
– more rapid passage out of the rumen- less cellulose is
digested- relatively greater digestion in the intestines.

30. D. CUBED ROUGHAGES
• Cubing- process in which dry hay is forced through dies
that produce a square product (ca. 3cm in diameter) of
varying lengths.
• Grinding before cubing- not required, but usually water is
sprayed on the dry hay as it is cubed.
• Alfalfa hay produces the best cubes.
• Although cubes have some advantages particularly that
they can be handled with mechanized feeding equipment,
they have never been as popular as expected.
• A partial answer may be that it is difficult to detect
(visually) low-quality hay after it has been cubed,
especially if green dyes have been added.

31. Thank you