Feed Additives

ANS 336Lecture 72/02/2001

Feed Additives - Defined

• As ingredients or combinations of ingredients added to the basic feed mix or parts thereof to fulfill a specific need.

• Usually used in micro quantities and requires careful handling and mixing.

Feed Additives- Cont’d

• Many classified as a drug.

• A substance, – Intended for use in the diagnosis, cure

mitigation and treatment or prevention of diseases in animals.

– Other than food intended to affect the structure or any function of the body of an animal.

Food and Drug Administration (FDA) Center for Veterinary Medicine

• Regulates use of Feed additives

• Clearance for testing of new feed additives requires obtaining an investigational new animal drug (INAD) to test a product.

• New animal drug Application( NADA) is required to market a product.

• Clearance IS required to use feed additives.

FDA

• Form 1900 required for human risk drugs.

• Category I – safest to use, no withdrawal period required.

• Category II – no residues allowed, withdrawal period required.

Delaney Clause - 1958

• Congress passed the Delaney Clause in 1958 – Zero Tolerance.

• No substance can be used as a feed additive, even in minute amounts, if it has been in any way implicated as an inducer of cancer in either human or beast.

Examples of Feed Additives

• Antibiotics– Compound produced by microorganisms that

inhibits the growth of microorganisms.– Examples of claims that can be listed on label.

• Improves performance (rate of gain).

• Improves feed efficiency or feed conversion.

• Increases growth rate.

• Increases milk production.

Examples of Feed Additives – cont’d

• Arsenicals– Controls parasites

• Nitrogurans– Antimicrobial compound that is produced more

by a microorganism.

• Sulfas– Antimicrobials– Residue problems, usage has been decreased.

AdditivesHormone like products

• Melengestrol acetate (MGA)– When fed to heifers to suppresses estrus– When fed to regulated estrus cycle.

• Implants– Ralgro– Synovex

• Somatotropin (rBST)– Increases milk production– Improves fertility ?

Growth Promotion and Feed Efficiency

• In general, Antibiotics are fed to reduce the incidence of Subclinical levels of bacterial infections of the digestive and respiratory tracts - thus credited with improved rate of gain and feed efficiency. Partial list…….– Chlortetracycline, Oxytetracycline,

Erythromycin– Lasalocid, Monensin, Penicillin

Growth Promoting

• Chemotherapeutic– An inorganic or organic compound that inhibits

the growth of organisms but is not produced by a living organism.

• Arsanilic acid – chicken and swine

• Carbadox - swine

• Ipronidazole - turkey

• Roxarsone – turkey and chicken

Medicinal Uses

• Coccidiostats– Prevent and treat Coccidiosis – Chickens and

Calves.– Monensin - cattle, chickens and turkey– Lasalocid – chickens, sheep turkeys– Amprolium cattle - chickens and turkeys

• Histostats– For protozoan disease affecting turkey – High

mortality less than 12 weeks of age.– Nitarsone

Medicinal Uses – cont’d

• Enteritis, Diarrhea, Dysentery– Carbadox – swine– Chlortetracycline – cattle, swine and chickens– Roxarsone – swine– Oxytetracycline – cattle, sheep, swine, chickens– Penicillin – chickens and turkeys– Arsanilic Acid - swine

Medicinal Uses – cont’d

• Antelmintic (worming) Agents– Fenbendazole (Safe-Guard) – swine and cattle– Invermectrin (Ivomec) – swine cattle– Levamisole hydrochloride(Tramisol) - cattle

and swine– Tumatel – cattle– Thiabendazole (TBZ) – cattle, sheep, swine

Misc. functions of Feed Additives

• Enterotoxemia (overeating) disease in Sheep– Tetracyclines.

• Fly control– Methoprene – cattle – Rabon – cattle, horse, sheep and swine

• Bloat– Poloxalene

Medicinal Uses cont’d

• Ketosis– Propylene glycol dairy cattle

• Foot rot– Chlortetracycline

• Stress– Tetracyclines – cattle, chicken, turkey– Erythromycin - chickens

Other Feed Additives

• Buffers– Chemical compounds that lessen the decrease

in pH caused by volatile fatty acid without causing any major increase in ruminal pH.

• pH = negative log10 of the hydrogen [ ], expressed in moles per liter.– Scale where 7 is neutral and anything below is

acid and anything above is alkaline.

Other Feed Additives cont’d

• Buffers cont’d– Sodium bicarbonate– Potassium bicarbonate– Calcium carbonate– Magnesium carbonate– Magnesium oxide– Sodium Bentonite– Lime – Feeding lime

Other Feed Additives• Antioxidants – compounds that prevent rancidity

of unsaturated fats.– Ethoxyquin

– Vitamin E

– Butylated hydroxytoluene (BHT)

– Butylated hydroxyanisole (BHA)

• Chemical Preservatives– Ascorbic acid

– Sodium nitrate

– Sorbic acid

– Citric Acid

– Sodium nitrate

Other Feed Additives

• Pellet binding Agents– Bentonite (calcium or sodium)– Ball clay– Lignin sulfonate– Hemicellulose extract– Molasses

Other Feed Additives

• Probiotics– Consist of specific microbial cultures or

ingredients or both that stimulate cultures capable of modifying the gastrointestinal environment to favor healthy tissue development.

– Lactobacillus– Streptococcus– Fungi (yeast and molds)– Aspergillus– Bacillus

Other Feed Additives

• Probiotics (reasons for use)– Increase or balance the beneficial intestinal bacteria– Reduce toxic by products of digestion– Reduce intestinal pH– Improve appetite– Alleviate symptoms of STRESS– Used in Foals, dairy calves/lactating dairy

cows,growing/adult horse, incoming feedlot cattle, sick pens newborn beef calves newborn pigs and various pets.

Other Feed Additives – Hormone like Products

• Melengestrol Acetate (MGA)– Synthesised steroid that is closely related

structurally to progesterone (P4)

– Not effective in pregnant or spayed heifers or in steers.

– Growth stimulation (6-8%) claimed– Improved feed efficiency (5-7%) claimed– Suppression of estrus and elevated estrogen –

stimulates release of growth hormone.

Other Feed Additives - Implants• Implant is a substance implanted into the

animal body and designed for slow but constant release for growth promotion, improved feed efficiency or control of a physiological function.– Ralgro – improve gain beef and sheep (8 –12

%) claimed. Effective 70 – 110 days.– Increases secretion of growth hormone

promotes skeletal growth without deposition of fat.

– Synovex (Implus-S,H,C) Estrodiol benzoate, progesterone, testosterone,

• Not for veal calves or animals raised for breeding purposes

Other Feed Additives

• Compudose – drug impregnated silicone rubber implant– Improves rate of gain 15-20 % claimed.

• Finaplix (S and H) - implanted pellet• Synthetic androgens

• 5-10 % improved gain

• Revelor - implant pellet

Other Feed Additives• Bovine Somatotropin (BST)

– POSILAC commercial recombinant rBST (FDA approved Feb 1994).

• 500 mg or 36mg/cow/day

– Cannot be administered orally– Subcutaneous injection of rBST every 14 days

starting day 63 postpartum.– Average increases of 8 to 10 lbs per day– Delayed dry matter intake– Require the same nutritional needs as

nonsupplemented cows.

Summary

• Feed additives must be used according to label.

• Stiff fines for non compliance.

• For best results use as directed.

• Protect your market and livelihood.