1. Feed Additives
Pages 319 – 325 (Chapter 6)

2. Why use them? Cause a desired response/benefit Alter metabolism
affect growth
change pH
manipulate microflora
improve digestion
increase yield
Reduce acidosis
Improve immune response
Increase palatability
Reduce fecal odor
Reduce joint pain

3. Major Classes Growth Promotion and Feed Efficiency Medicinal Uses
Antibiotics
Medicinal Uses
Coccidiostats, worming agents
Others
Buffers and Neutralizers
Antioxidants
Preservatives
Binders
Direct Fed Microbials
Coloring Agents
Flavorings
Hormonelike products
Feed Additives
Implants

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. -agonists 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)

29.  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

34. Microorganisms found to be appropriate for use n animal feeds
*Enterococcus cremoris
*Enterococcus diacetylactis
*Enterococcus faecium
*Enterococcus intermedius
*Enterococcus lactis
*Enterococcus thermophilus
Yeast
Aspergillus niger
Leuconostoc mesenteroides
Pediococcus acidilacticii
Pediococcus cerevisiae (damnosus)
Pediococcus pentosaceus
Propionibacterium acidpropionici (cattle only)
Propionibacterium freudenreichii
Propionibacterium shermanii
Saccharomyces cerevisiae
Aspergillus niger
Aspergillus oryzae
Bacillus coagulans
Bacillus lentus
Bacillus licheniformis
Bacillus pumilus
Bacillus subtilis
Bacteroides amylophilus
Bacteroides capillosus
Bacteroides ruminocola
Bacteroides suis
Bifidobacterium adolescentis
Bifidobacterium animalis
Bifidobacterium bifidum
Bifidobacterium infantis
Bifidobacterium longum
Bifidobacterium thermophilum
Lactobacillus acidophilus
Lactobacillus brevis
Lactobacillus buchneri (cattle only)
Lactobacillus bulgaricus
Lactobacillus casei
Lactobacillus cellobiosus
Lactobacillus curvatus
Lactobacillus delbruekii
Lactobacillus farciminis (swine only)
Lactobacillus fermentum
Lactobacillus helveticus
Lactobacillus lactis
Lactobacillus plantarum
Lactobacillus reuterii
Leuconostoc mesenteroides
Pediococcus acidilacticii
Pediococcus cerevisiae (damnosus)
Pediococcus pentosaceus
Propionibacterium acidpropionici (cattle only)
Propionibacterium freudenreichii
Propionibacterium shermanii
Saccharomyces cerevisiae

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