Feed Additives AnSci 320 2-27-12 Lance Baumgard baumgard@iastate

1. Feed Additives AnSci 320 2-27-12 Lance Baumgard baumgard@iastate.edu

2. Feed Additives • Antibiotics: disease prevention • Coccidiostats: control parasites • Xanthophyll: makes egg yolks yellow • 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

3. FEED ADDITIVES • Feed additives used in livestock supplements and rations to improve performance & animal health. • 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 marketingof animal products has led to more uniformity in regulations among countries. • Animal products must comply with the laws ofthe countries to which they are being sold.

4. FEED ADDITIVES • AFCO (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 ofsafe and effective animal feeds. • AFCO defines a feed additive as… • "an ingredient or combination of ingredients addedto the basic feed mix …to fulfill a specific need." • " …usually used in micro quantities and requirescareful handling and mixing"

5. 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 ormetabolism of the animal.

6. 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.

7. 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.

8. USE OF FEED 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 usedin feed until adequate research submitted to the FDA proves the drug is both safeandeffective. • In developing a new drug for use with animals, manufacturers must go through extensive testing.

9. USE OF FEED 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 sourcesare subject to less demanding regulation.

10. USE OF FEED ADDITIVES CLASSED AS DRUGS Antibiotics • Antibiotics are compounds produced by microorganisms. • With properties of inhibiting 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.

11. USE OF FEED ADDITIVES CLASSED AS DRUGS Antibiotics • Antibiotics have been effective, in general, as production improvers when fed at low levels to young, growing animals.

12. USE OF FEED ADDITIVES CLASSED AS DRUGS Antibiotics • Use tends to result in an increased feed intake. • Growth is nearly always increased, particularly with animals exposed to adverse environmental conditions. • Feed intake usually decreases in ruminants • Response in growth & feed efficiency varies by animal species, time of year and location. • Antibiotic-fed animals are less apt to go off feed. • Antibiotics may be useful for other purposes, such as the prevention and control of a wide variety of animal and poultry diseases. • As a rule, reduce the incidence or severity of several types of diarrhea

13. USE OF FEED 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. • Antibiotics are often used at therapeutic levels in treatment or control of many common diseases.

14. USE OF FEED ADDITIVES CLASSED AS DRUGS Antibiotics • At higher levels for therapeutic treatments, antibiotics have been very useful for… • Cattle for 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 usage.

15. USE OF FEED 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.

16. Dietary Polysaccharides Bacterial enzymes Monosacharides (glucose: 6 Carbons) CH4 Glycolysis H CO2 Pyruvate (3 C) Propionate (3C) Acetate (2 C) Butryate (4C)

17. USE OF FEED 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 additives are approved for horses, rabbits, sheep, goats, ducks, pheasants & quail. • No approvals are given for geese or pets suchas cats and dogs. • The primary reason is the cost of obtaining approval in relation to potential sales volumes.

18. USE OF FEED ADDITIVES CLASSED AS DRUGS Antibiotics • Many antibiotics approved for cattle are tested with sheep, but few are ever approved for sheep. • Even fewer for species other than cattle, swine, chickens, and turkeys, because of the costs.

19. USE OF FEED 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 levelsof chlortetracycline and erythromycin. • Manufacturer approval must be obtained forusing 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. USE OF FEED ADDITIVES 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. USE OF FEED 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. USE OF FEED ADDITIVES CLASSED AS DRUGS Coccidiostats • Coccidia are microscopic parasites. • Coccidiostats include a wide variety of compounds, ranging from a number of synthetic drugs to severalof 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. USE OF FEED 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 yetdeveloped bacterial resistance, as is thecase for some antibiotics. • Nitrofurans are often used in combination with other drugs, especially with swine and poultry.

24. USE OF FEED ADDITIVES CLASSED AS DRUGS Sulfas • The first sulfa drug was synthesized in the 1930s, and early ones were used extensively against some human diseases very difficult to treat at the time. • Most sulfas present problems with tissue residues, and some of the injectables resultin tissue residues in edible cuts of meat. • There has been a gradual withdrawal of sulfadrugs as feed additives. • Most of problems alleviated by sulfas can be treated successfully with other drugs.

25. USE OF FEED ADDITIVES CLASSED AS DRUGS Hormone-like Production Improvers • Melengestrol acetate 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. USE OF FEED ADDITIVES CLASSED AS DRUGS Hormone-like Production Improvers • Although not feed additives, several productsare 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. Implants • Implants for Growth Stimulation • Designed for slow release • Growth promotion, feed efficiency • Products • Ralgro • Use in calves, growing cattle, feedlots animals • 70-110d response • Cattle should be reimplanted every 65-100d for maximum • Magnum • Double dose of Ralgro • Best in initial 70-90d on feed

28. Implants • Synovex or Implus • Different forms for different cattle • Stimulates muscle deposition • Increases growth hormone secretion • Revalor • Claims to improve gain 15-20% • Improves feed efficiency 15% • Duration of response 100d • May reduce marbling

29. Feed Additives and Implants • Hormone Implants • Most are pelleted • Synthetic or natural • Improves rate of gain and feed efficiency

30. Hormone Implantation

31. USE OF FEED 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.

32. Steroids (Estrogens and Androgens) • Classification • Estrogenic • Androgenic • Predominate illegal steroid in humans • Progestin • Non-steroidal

33. Steroids (Estrogens and Androgens) • Animal agriculture • Approved for beef • Not as effective in pigs • Effects • Increased protein accretion • Decreased fat accretion • Increased average daily gain • Increased feed efficiency

34. Negative side effects (humans) • Both Genders • Increased heart disease, liver cancer, acne, male pattern baldness • Females: • Decreased breast size, deepening of voice, increase in body hair • Males: • reduced sperm production, shrinking of the testicles, impotence, difficulty or pain in urinating, baldness, and irreversible breast enlargement, testicular shrinking

35. Steroid summary • Improves animal performance • Approved for beef cattle • Taken illegally by body builders • Used legally for many health reasons

36. -agonists • Reasons for interest: • Human medicine • Branchodialators • Agriculture • Increase growth • Enhanced muscle • Decreased fat • Approved for pigs and cattle • Feed supplement • Orally active

37. -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

39. control 50 d/150.5 kg feed 100 kg of bw 46 d/132 kg feed -agonist 75 kg Ham 14.3 kg 13.3 kg Loin 11.2 10.7 Shoulders 11.9 11.2 Belly 10.2 10.3 Carcass lean 43.9 39.4 Moody et al., 2000

40.  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

41. Buffers and Neutralizers • Buffers & Neutralizers • Compounds that minimize pH decreases • Sodium bicarbonate • Potassium bicarbonate • Calcium carbonate • Mag oxide • Mag carbonate

42. DFMs and 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

43. 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.