4. Examples
• Antibiotics: disease prevention
• Coccidiostats: control parasites
• Xanthophyll: makes egg yolks yellow
– Cantaxanthin
• Hormones (hormone like): increases growth
• Yeast, Fungi, Direct fed microbials:
• Buffers: HCO3 etc.. Prevent rumen acidosis
• Antioxidants: prevents feed from getting rancid
• Pellet Binders: keeps feed in pellet form
• Flavoring Agents: makes feed taste better
• Surfactants: lipid digestion, increase milk production, yield
• Anionic salts: acidify diet to increase Ca absorption
5. FEED ADDITIVES
• Use of feed additives is strictly regulated in the
developed countries, and many others, to ensure:
– Human food safety
– Animal safety
– Additive efficacy
– Minimal environmental impact
• Dramatic increase in globalization of marketing
of animal products has led to more uniformity in
regulations among countries.
– Animal products must comply with the laws of
the countries to which they are being sold.
6. FEED ADDITIVES
• AAFCO (Association of American Feed Control
Officials) provides the U.S. mechanism for
developing/implementing uniform & equitable
laws, regulations, standards, and enforcement
policies.
– Regulating manufacture, distribution, and sale of
safe and effective animal feeds.
• AAFCO defines a feed additive as…
– "an ingredient or combination of ingredients added
to the basic feed mix …to fulfill a specific need."
– " …usually used in micro quantities and requires
careful handling and mixing"
7. FEED ADDITIVES
• In practice, feed additives are defined as feed
ingredients of a nonnutritive nature that…
– Stimulate growth or other types of performance.
– Improve the efficiency of feed utilization.
– Are beneficial in some manner to health or
metabolism of the animal.
8. FEED ADDITIVES
• Of the groups of additives classed as drugs, the major
groups include many different compounds:
– Antibiotics, nitrofurans and sulfa compounds.
– Coccidiostats, wormers (antihelminthics & others),
and hormone-like compounds.
• Feed additives have been used extensively in the U.S.
and many other countries since the discovery &
commercial production of antibiotics and sulfa drugs in
the late 1940s.
– The European Union recently banned feeding of
antibiotics to animals meant for human consumption.
9. FEED ADDITIVES
• Animal products are routinely tested to ensure
that feed additives are being used correctly.
– Use of feed additives has been beneficial to livestock
producers under our modern methods of production.
• Development of intense systems of management
and concentration of animals has been made
possible only because additives could be used to
help control various diseases and/or parasites.
– Broilers, laying hens, growing-finishing pigs, and
fattening cattle and sheep.
10. ADDITIVES CLASSED AS DRUGS
• In the U.S., use & regulation of additives classed
as drugs is controlled by the Center for Veterinary
Medicine, within the FDA.
– To determine that drugs & medicated feed are
properly labeled for intended use and that animal
feeds and food derived from animals are safe to eat.
• Federal law states no animal drug can be used
in feed until adequate research submitted to the
FDA proves the drug is both safe and effective.
– In developing a new drug for use with animals,
manufacturers must go through extensive testing.
11. ADDITIVES CLASSED AS DRUGS
Requirements for Medicated Feed
• FDA requirements for medicated feed focus on
mixers who use human-risk drug sources.
– Mixers who do not use human-risk drug sources
are subject to less demanding regulation.
12. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Antibiotics are compounds produced by
microorganisms.
– inhibit growth/metabolism of some (not all) other
microorganisms.
– In some instances, they may be toxic to warm-
blooded animals.
– Most antibiotic names end in -cin or -mycin.
• All antibiotics used commercially for growth
promotion are produced by fermentation processes
using fungi or bacteria.
13. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Antibiotics are effective at improving production
when fed at low levels to young, growing
animals.
14. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Improve feed efficiency.
– Growth is nearly always increased, particularly with
animals exposed to adverse environmental conditions.
– Feed intake usually decreases in ruminants.
– Varies by animal species.
– Antibiotic-fed animals are less apt to go off feed.
– Can control a wide variety of diseases.
– As a rule, reduce the incidence or severity of several types
of diarrhea
15. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Some are approved at low levels of continuous use for
reducing the incidence of…
– Enterotoxemia (overeating disease) in lambs.
– Liver abscesses in fattening cattle.
– Diarrhea in young mammals deprived of colostrum.
• In poultry, some claims include…
– Reduction in respiratory disease.
– Nonspecific enteritis (blue comb) & infectious sinusitis.
– Improved egg production and hatchability.
16. ADDITIVES CLASSED AS DRUGS
Antibiotics
• At higher levels for therapeutic treatments, antibiotics
have been very useful for…
– Cattle - treating or preventing stresses associated with
transportation and adjustment to new conditions.
– Treatment of diseases such as anaplasmosis in cattle and
bacterial enteritis in swine.
– Respiratory diseases, diarrhea, fowl cholera, fowl typhoid,
and breast blisters in poultry.
• In most instances, the higher levels are not approved
for long-term additive feeding usage.
17. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Two antibiotics for use in cattle, monensin and
lasalocid, are unusual in that they give a good
response in both growing and mature animals.
– Approval was first received for use as
coccidiostats with poultry.
– Both of these antibiotics are quite toxic to horses.
18. ADDITIVES CLASSED AS DRUGS
Antibiotics
• Obtaining approval for new feed additive drugs has
become more difficult in recent years.
– More investigative effort & expense are involved.
– As a result, not many new additives have been approved in
recent years.
• Very few antibiotic additives are approved for horses,
rabbits, sheep, goats, ducks, pheasants & quail.
– No approvals are given for geese, dogs, cats, exotics.
• The primary reason is the cost of obtaining approval in
relation to potential sales volumes.
19. ADDITIVES CLASSED AS DRUGS
Antibiotics
• In poultry, the trend is to use one or more
antibiotics in nearly all broiler feeds.
– Most can be used for layers, except high levels
of chlortetracycline and erythromycin.
• Manufacturer approval must be obtained for
using different combinations of antibiotics.
– Or combinations of antibiotics & other controlled drugs.
• Far more drug combinations have been approved for chickens &
turkeys than all other animals combined.
– It is illegal to feed antibiotics at different levels or in
different combinations from those previously approved.
20. CLASSED AS DRUGS
Arsenicals
• Arsenicals are all synthetic compounds
(chemotherapeutic agent) & include a number of
drugs used in turkey, chicken, and swine rations.
– Developed as a means of controlling parasites.
– Some compounds stimulate growth in the same
manner as antibiotics.
– The effect can be additive to antibiotic stimulation.
• Several arsenicals have claims of improved growth
production as well as improved feed efficiency for
chickens, turkeys, or swine.
– And control of blackhead in poultry & diarrhea in
swine.
21. ADDITIVES CLASSED AS DRUGS
Arsenicals
• Arsenicals have the disadvantage that they may
accumulate in body tissues, particularly the liver.
– At the levels fed, they are not considered to be toxic.
– All have a minimum 5-day withdrawal period before
animals are to be slaughtered for human food.
22. ADDITIVES CLASSED AS DRUGS
Coccidiostats
• Coccidia are microscopic parasites.
– Coccidiostats include a wide variety of compounds,
ranging from a number of synthetic drugs to several
of the antibiotics.
• These drugs are of considerable importance to the
poultry producer because close confinement
methods used in modern facilities accentuate the
possibility of coccidiosis outbreaks.
– Evidence suggests coccidiosis is becoming a greater
problem with sheep & cattle in close confinement.
23. ADDITIVES CLASSED AS DRUGS
Nitrofurans
• The nitrofurans are antibacterial compounds
and are effective against a relatively large
number of microbial diseases.
– Continued use of nitrofurans has not as yet
developed bacterial resistance, as is the
case for some antibiotics.
24. ADDITIVES CLASSED AS DRUGS
Sulfas
• Reduction in use
– Problems with tissue residues
• Most of problems alleviated by sulfas can be
managed with other additives.
25. ADDITIVES CLASSED AS DRUGS
Hormone-like Production Improvers
• Melengestrol acetate (MGA) is the only
hormone-like production improver remaining
on the approved list.
– Extensively used with beef heifers; it acts to
suppress estrus, resulting in more efficient and
more rapid gain.
26. ADDITIVES CLASSED AS DRUGS
Hormone-like Production Improvers
• Although not feed additives, several products
are available for use as subcutaneous implants.
– Hexestrol, (outside the U.S.)
– Zeranol (Ralgro™), said to be an anabolic agent.
– Synovex™, a combination of estrogen & progesterone.
– Rapid Gain™, a combination of testosterone &
estrogen
– Steer-oid™, a combination of progesterone and
estradiol.
• A high percentage of growing- finishing cattle are
treated with one or another of these implants.
27. ADDITIVES CLASSED AS DRUGS
Hormone-like Production Improvers
• In ruminants, natural or synthetic hormones
produce a response that results from increased
nitrogen retention accompanied by an
increased intake of feed.
– Increased growth rate; Improvement in feed
efficiency.
– Reduced deposition of body fat, which may, at
times, result in a lower carcass grade for animals
fed to the same weight as nontreated animals.
28. • Molecules that structurally resemble epinephrine
– Caffeine, ephedrine, aspirin
• Easily made in the lab
• Muscle:
– Increase in muscle synthesis
– Decrease in muscle breakdown
• Fat
– Decrease in lipogenesis
– Increase in lipolysis
• Ractopamine (Paylean)
β-agonists
29. β Agonist summary
• Structurally resembles epinephrine
• Increases muscle synthesis
– Need to increase the protein % of diet
• Decreases fat content
• Orally active
• Desensitization
• Recently approved for pigs and beef cattle
30. Antioxidants
• Used to prevent rancidity of unsaturated fatty
acids
• Inclusion rates up to 0.25 Lb per ton
• BHA/BHT (Butylated hydroxyanisole or
toluene)
• Ethyoxiquin
• Vitamin E
• Rosemary
31. Preservatives
• Used to prevent feed deterioration
(mold/bacteria inhibitors)
– Vitamin C
– Calcium sorbate
– Citric acid
– Phosphoric acid
– Propylene glycol (toxic in cats)
– Sodium propionate
– Sodium metabisulfate
32. Buffers and Neutralizers
– Buffers & Neutralizers
• Lessen the decrease in pH caused by VFA production
• Valuable for use in high concentrate diets to ruminants
but not high forage diets
• Examples
– Sodium bicarbonate (most effective and most common)
– Potassium bicarbonate
– Calcium carbonate
– Mag oxide
– Mag carbonate
33. DFMs and Yeast
www.microbialcompendium.com
– Bacteria, Enzymes, Mold, Oligosaccharides, Yeast
– Lactobacillus, streptococcus, fungi, aspergillus, bacillus
– Probiotics
• Scientifically inconsistent
• Consist of microbial cultures
– Can stimulate cultural growth
• Reasons for use
– Increase/balance beneficial bacteria
– Reduce toxic byproducts of digestion
– Support rate of gain and feed efficiency
– Alleviate/minimize stress
• Various times for use
– When do you use them?
• Available forms
– Feed additives
– Water dispensing
– Bolus/gel form
35. Pet Food• Pet food, including dry and canned food and pet treats, is
considered to be animal feed. Like other animal feed, FDA
regulates pet food and establishes standards for labeling.
• Pet food labeling is regulated at two levels: federal and state.
The federal regulations, enforced by FDA’s Center for
Veterinary Medicine, establish standards that apply to all
animal feeds:
– proper identification of the product
– net quantity statement
– manufacturer’s address
– proper listing of ingredients
• FDA carries out its animal feed regulatory responsibilities in
cooperation with state and local partners, and works together
with AAFCO on uniform feed ingredient definitions and
proper labeling.
36. Lab Assignment
• Find a research article (journals only) –
additive
• Cite the study
• Indicate species, number animals used,
treatments (doses/inclusion rates)
• Intended benefit
• Outcome
