Feed Additives and Growth Promotants

1. Feed Additivesand Growth Promotants

2. Feed Additives • Compounds that are added to the diet – other than to supply nutrients to the animal • Example: Antibiotics…no “nutrient requirement” for antibiotics • Urea is not considered feed additive – provides a source of dietary protein (in the form of nitrogen) • Additives used to enhance production efficiency and improve health

3. Feed Additives • Feed additives used in small quantities eg Melengesterol Acetate (MGA) • Toxicity and end-product residue….mixing, delivery and consumption critical • Most feed additives are regulated for these reasons • No one…not even a vet…can authorize use off label • Feed industry developed premixes for effective and safe use

4. “ It is essential to abide by recommended feeding levels with any feed additive”

5. Regulation of Additives • US- Federal Food and Drug Administration (FDA) • Canada- Food Production and Inspection Branch of Agriculture Canada

6. Feed label requirements • “medicated” must appear under the name of the feed • Purpose of the drug • Name and amounts of all active drugs • Required withdrawal period • Cautions against misuse • Directions for the use of the feed

7. Mixing and residue avoidance • Important for safe use • May result in higher production costs • Undesirable side effects

8. Financial loss includes • Carcasses may be condemned • Additional regulations or restrictions • Animals are held until they are free of the illegal substance

9. Mixing recommendations • Know the labeled uses, mixing instructions, and withdrawal times • Clean the mixer before use • Premix the drugs in a large enough quantity • Follow the manufacturer’s instructions • Establish order of mixing

10. Keeping Records • Date the batch was mixed • Mixing order and the amount of medication • Mixing time for the batch • Location where the feed is stored • Number, age, and weight of the animal fed • Medication that was used, the amount, and the concentration • Date of cleaning equipment

11. Health concerns • Resistant strain of microorganisms • Ban would raise costs of animal product of the consumer • Increase the death loss among animals being raised • Possible carcinogenic effects

12. Effects of Feed Additives • Primary Effects: • Improve feed efficiency • Promote faster gains • Improve animal health • Increase production of animal products • Secondary Effects: • Reduce acidosis, coccidiosis, bloat, liver abscesses, suppress estrus and control foot rot.

13. Kinds of feed additives and Hormones • Antimocrobial Drugs • Hormones and Hormonelike Compounds • Anthelmintics • Other Feed Additives

14. Antimocrobial Drugs • Antibiotics • Produced by living microorganisms • Chlortetracycline, neomycin, oxytetracycline. Penicillin. Streptomycin, tylosin • Chemoantibacteral • Made from chemicals • Carbadox, furazolidone, nitrofurazone, sulfamethazine

15. Antibiotics • Classified as antibacterial agents • Limit growth of certain bacteria • Bacteria can cause clinical sickness or subclinical reductions in health (morbidity) that reduces performance • Generally approved for low-level use • Animal response to antibiotics depends on feeding conditions at the time they are used • Difficult to quantify actual response that can be expected

16. Antibiotics • Many antibiotics are normally produced in organisms found naturally in the soil & other places • People exposed for centuries • Generally, used correctly results in healthier animals • No risk to people or livestock?

17. Antibiotics • The primary reason to feed antibiotics to ruminants is to control liver abscesses, foot rot & secondary infections/diseases as a result of shipping stress • Control of liver abscesses is the primary reason to continuously feed antibiotics • Cattle on high grain diets: •  episodes of acidosis =  liver damage and infection

18. Chlortetracycline • Aureomycin, Aureo S700 • Numerous recommendations based on production level of animal • Receiving calf AS700 – 350mg of each • 48 hour withdrawal time • Aureomycin – 5 days only • AS700 – 28 days

19. Oxytetracyline • Terramycin • 75 mg/hd/d =  liver abscesses (cattle) • 0.5 - 2.0 g/hd/d =  shipping fever complex (cattle) • Feed 3 - 5 days before & after arrival • 7 day withdrawal time • Tylosin • Tylan • 8 - 10 g/t or 60 - 90 mg/hd/d (cattle) • Cleared for use with Rumensin and/or MGA

20. Hormones and Hormonelike Compounds • Naturally produced in the animal’s body • Regulate many body functions, such as growth, metabolism, and reproduction • Increase the rate of protein synthesis and muscle development • Improve feed efficiency and increase the rate of growth

21. Hormone Implants • Contain active ingredients that are hormone like • Side effects include: • Buller steers, high tailheads, and udder development • Kinds of implants: • Ralgro. Synnovex. Imlus-S. compodose. Ravalor-S

22. Implanting Procedure • Restrain thee animal • Don’t use an instrument with a dull needle • Clean needle and implantation site • Implant on the back surface of the ear • Point instrument toward the head • Withdraw the needle slightly before starting the implant.

23. Anthelmintics • Dewormers • Compounds used to control various species of worm infested in animals • Hygromycin, loxon, phenothiazine, piperzine, thiabendazole, and tramisol.

24. Other Feed Additives • Balance pH level/buffers • Bloat regulators • Prevent stress • Probiotics • Organic acids • Estrus suppressants • Coccidiostats • Ionophores • Xanthophyll: makes egg yolks yellow • Tranquilizers: calms nerves (cattle, turkeys) • Antioxidants: prevents feed from getting rancid • Pellet Binders: keeps feed in pellet form • Flavoring Agents: makes feed taste better

25. Use of feed additives for livestock

26. Beef Cattle • Antiboiotic • 3 to5% improvement in feed efficiency • Rumensin or Bovatec • Improve feed efficiency, rate of gain, affect fermentation • Hormones • Melengestrol acetate for heifers • Suppresses estrus • Increases rate of gain and feed efficiency • No effect to bulls or steers

27. Dairy • Most antibiotics are used for young dairy animals, lactating dairy animals are prohibited from the use • Forage preservatives • Buffers • Propylene glycol • BST

28. Sheep and Goats • Few feed additives produces due to the small industry • Feeder lambs respond well to antibiotics

29. Swine • Young swine have the greatest economic return with use of antibiotics • Anthelmintic treatment is profitable is young swine

30. Poultry • Lasalocid sodium and monensin sodium are the most common additives • Improve feed efficiency and growth

31. Ionophores • Ionophores selectively affect certain microorganisms by altering the passage of ions through pores on their outer cell membrane • Originally used as a coccidiostat in poultry industry…later shown to enhance feed efficiency in cattle by altering the microbial fermentation of feed in the rumen

32. Ionophores • Results in selection of certain microorganisms in the rumen • Inhibits or depresses certain MCO growth • Alters rumen fermentation • Usually  propionate production • Reduction in protein degradation in the rumen • Propionate tends to enhance energetic efficiency of growth • Reducing protein degradation increases amount of protein that bypasses rumen to lower digestive tract

33. Effects of ionophores: • Improve efficiency of energy metabolism by changing the VFA profile &  energy lost in fermentation •  energy retention • Reduce digestive upsets = reduced stress = improved animal performance

34. Too high of a level of ionophore can reduce cellulolytic bacteria •  fiber digestion •  rumen protein = ruminal protein shortage • Growing cattle: high-roughage diets • Improved daily gain (5 - 15%) & feed efficiency (8 - 12%) • Finishing cattle: high-concentrate diets • Improved feed efficiency (6 - 8%) and subtle improvement in daily gain (1 - 3%) • Prevention or control of bloat and acidosis

35. Common ionophores on the market: • Rumensin(Monensin Sodium) • 20 - 30 g/ton • Bovatec(Lasalocid Sodium) • 10 - 30 g/ton • 1 mg/2.2 lb. of BW = control of coccidiosis • Cattlyst(Laidlomycin Propionate Potassium) • 5 - 10 g/ton

36. Use of ionophores in levels higher than approved is not only illegal but can be toxic to cattle Horses are especially susceptible to ionophore toxicity

37. Coccidiostats • Protozoal organisms – can invade and destroy the intestinal mucosa • Present in most animals at subclinical numbers….generally do not affect performance or health • Numbers increase to a point where production is impaired

38. Coccidiostats • Cause irritation of the digestive tract….scours and bloody stools • Stress (due to shipping), abrupt diet changes, weather changes can all cause episodes of clinical coccidiosis • Interpretation of fecal coccidia is difficult, since a clinical problem can exist with low coccidia counts

39. Coccidiostats 4 additives are approved for prevention and treatment Amprolium (Corrid) Decoquinate (Deccox) Lasalocid (Bovatec) Monension (Rumensin)

40. Estrus Suppressants • Melengesterol Acetate (MGA) • Synthetic hormone similar in structure and activity to progesterone • Steroidal feed additive used to suppress estrus (cyclic sexual activity or heat) • Results in improvements in growth rate and feed efficiency • Breeding females: • Used to synchronize females for breeding

41. Estrus Suppressants • Feedlot heifers: • Suppress estrus =  growth performance • +3 - 7% for ADG & FE •  injury,  dark cutters,  energy expended by chasing heifers • 0.25 - 0.50 mg/hd/d (cattle) • Cleared for use with Rumensin, Bovatec & Tylan • 48 hour withdrawal period

42. Estrus Suppressants • Response of feedlot heifers to MGA depends on: • The age of the heifer • Number of sources of heifers being fed together • Amount of space per heifer • Implant effects • Adequate mixing

43. Buffers • Added to the diet to aid in resisting pH changes of the rumen when acids are present • Large quantities of organic acids produced in rumen by microbial fermentation • Reduces incidence of acidosis on high grain diets • SALIVA is principle source of rumen-buffering agents • Performance is variable • -2 - 5% improvement in ADG & FE

44. Buffers • Sources: • Sodium Bicarbonate: 0.75 - 1.5% diet DM • Limestone: 1.0% diet DM • Sodium Bentonite: 1 - 2% diet DM • Magnesium oxide: 0.5 - 0.75% diet DM

45. Growth Promotants in Ruminants • Redirection of nutrients from fat deposition to lean tissue deposition. •  Growth hormone secretion •  pituitary response to GHRH =  GH secretion •  steroidal effect on growth of skeletal muscles through  [IGF’s]

46. Growth Promotants in Ruminants • Given to cattle to improve: • Feed Efficiency: +15 - 25% in growing cattle +10 - 12% in finishing cattle • Daily Gain: +.33 lb./d in growing cattle +10 - 15% in finishing cattle • 4 - 16% improvement in DMI

47.  cost of gain,  % choice carcasses (25%),  % lean • Altered or aggressive pen behavior (bullers) • Estradiol implants reduce NEg requirement by 5% • 2 E2 implants = 18 - 20% NEg requirement reduction

48. Most implants are effective from 50 to 100 days • Selection for growing & finishing cattle • Most are cleared for use in confinement cattle and some are available for grazing cattle • There are 6 individual component implants & 10 combination implants currently on the market • Implant wars = changing companies and products

49. Estrogens • Estradiol 17 (Compudose) • Estradiol Benzoate (71% E17) - Synovex • Zeranol (produced from the production of mold) Ralgro • Androgens • Testosterone Propionate (Component) • Trenbolone Acetate(TBA) Finaplix

50. Progesterones • Progesterone (Component) • Melengesterol Acetate (MGA) Combination implants Estradiol & TBA RevS Estradiol benzoate & TBA Synovex