1. Feed Additives & Hormone Implants
Animal Science II
Unit 7

2. Objectives
Discuss the general use and purpose of feed additives and hormone implants
Describe the proper method of hormone implantation
Discuss the proper use of feed additives for various species of animals
Discuss labeling and regulation of feed additives
Discuss the proper mixing of feed additives in complete rations
Discuss health issues and concerns relating to the use of feed additives.

3. Feed Additives Used to Not considered nutrients Used in small amounts
Improve feed efficiency
Promote faster gains
Improve health
Increase production of animal products
Not considered nutrients
Used in small amounts
Require careful handling and mixing
Came into use in the early 1950’s

4. Hormone Implants Pelleted, Synthetic compounds
Placed under the skin or in the muscle
Used to lower production costs by improving both rate and efficiency of gain
Mainly used in beef cattle

5. Hormone Implants and Feed Additives
Sometimes called performance stimulants
Wide variety have been developed, tested and approved for use
Some have been discontinued due to toxicity, cost, lack of proven benefit or excessive residues in meat

6. Types Antimicrobial compounds Hormones Hormone like substances
Antibiotics and chemoanticacterials
Hormones
Hormone like substances
Anthelmintics
Dewormers
Buffering agents
Feed flavors
Bloat preventatives

7. Antimicrobial Drugs
Kill or slow down the growth of some kinds of microorganisms
Often used as feed additives for livestock and poultry
Used at a subtherapeutic level of use to keep harmful microbes under control

8. Difference Between the Antibiotics and Chemoantibacterial Compounds
Major difference is in the way they are produced
Antibiotics are produced from living microorganisms
Chemoantibacterial compounds are made from chemicals
An antibiotic and antibacterial are combined into one compound called a chemobiotic
They are combined to combat a problem that is not susceptible to either one individually

9. Common Antibiotics Used in Livestock Production
Chlortetracycline (Aueromycin)
Neomycin
Oxytetracycline (Terramycin)
Penicillin
Streptomycin
Tylosin
Polyether antibiotics are called ionophores and are usually used in the production of ruminant animals
Monensin (Rumensin)
Lasalocid sodium (Bovatec)

10. Common chemoantibacterial Compounds
Carbadox
Furazolidone
Nitrofurazone
Sulfamethazine

11. Use of Antibiotics
Response varies among species and feeding conditions
Little or no benefit gained from the feeding of antibiotics in conditions that are free of harmful microorganisms
Research in livestock nutrition shows several factors that explain why antibiotics increase rate of gain, improve feed efficiency or improve the general health of the animal

12. Nutrient Sparing Substances
The substance allows animals to use available nutrients more effectively
Some antibiotics stimulate microbes in the digestive tract to produce more nutrients than they would without the antibiotic

13. Metabolic Rate in Young Growing Animals
When fed at low levels in the ration
Increase daily feed intake
Conversion of feed to meat is faster and more efficient
This is compared to animals that are not fed antibiotics in their ration

14. Subclinical Diseases
Disease that is present in the animal’s body at levels too low to cause visible effects
Antibiotics can control these disease continuously
Result is a more vigorous and healthy animal
Also results in a more uniform rate of gain

15. Broad and Narrow Spectrum Antibiotics
Broad Spectrum- control many different microorganisms
Preferred for use as feed additives
Generally give better results in terms of rate of gain, feed efficiency, improved animal health
Narrow spectrum- control only a few microorganisms
Used to control specific disease problems that may be present in the group

16. Hormones Produced in the animals body
Natural hormones are secreted into body fluids such as the bloodstream by various glands in the body
Regulate body functions such as growth, metabolism, reproductive cycle

17. Hormone like Compounds
Synthetic substances that act like hormones
Both hormones and hormone like compounds are produced commercially for use as feed additives, primarily in beef nutrition

18. Androgen, Progestogens, Estrogens
Produced by sex glands of the body
Increase rate of protein synthesis and muscle development
Used in rations to improve feed efficiency and rate of growth
Beef cattle have shown the greatest response to these as feed additives and implants

19. The Controversy Over Hormone Use
DES
Approved in 1954
Disapproved in 1972
Reapproved
Banned in 1979
European Union (EU)
Banned importation of meat for human consumption that has been treated with anabolic agents
1988 WTO ruled that the EU ban was in violation of trade laws
As of summer 1999 the issue was not resolved

20. Anthelmintics Dewormers May be provided in either feed or water
Worms reduce feed efficiency and rate of gain
Good management practices can also help keep worm infestations to a minimum.

21. Other Feed Additives Coccidiostats
Used in poultry rations to prevent coccidiosis
Iodinated casein (Thyropotein)
Used to increase the amount of hormone thyroxin
Poloxalene (Bloat Guard)
Bloat preventative
Breaks up the foam and slime layer and allows gases to escape the rumen
Others
Tranquilizers
Antioxidants
Copper compounds
Probiotics
Organic acids