Abstract
This paper is a review of the non-nutritive, exogenous substances which improve animal growth and feed conversion. These agents are categorized according to the methods through which they improve livestock performance. Categories defined and discussed include antimicrobial production improvers, rumen additives, anabolic growth promotants and “other” production improvers. The exogenous substances covered include primarily drugs with an approved New Animal Drug Application (NADA) with the U.S. Food and Drug Administration. Two exceptions are thiopeptin, an antibiotic, and trenbolone acetate, a synthetic androgen. These compounds are discussed because they work through modes of action where approved drugs are not available. Agents for the control of parasitic diseases will not be covered. The modes of action through which these substances act are examined in detail. Some recent studies involving the effects of exogenous hormones on the growth, feed conversion and carcass composition of normal, growing lambs are presented. The hormones discussed include growth hormone, prolactin and thyrotrophin-releasing hormone. Also, a study on the effects of exogenous GH on milk production is included. Finally, the future of production improvers for livestock is discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
