Feed Additives & Hormone Implants

Animal Science II Unit 7

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.

Feed Additives

 Used to   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

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

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

Types

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

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

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

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)

Common chemoantibacterial Compounds

    Carbadox Furazolidone Nitrofurazone Sulfamethazine

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

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

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

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

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

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

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

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

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

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.

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