Document Detail

Perspectives on the application of zilpaterol hydrochloride in the United States beef industry.
MedLine Citation:
PMID:  20382871     Owner:  NLM     Status:  MEDLINE    
Zilpaterol hydrochloride (ZH) is a beta-adrenergic agonist approved to be fed at a rate of 8.3 mg/kg (100% DM basis) during the final 20 to 40 d of the finishing period in beef cattle followed by a minimum 3-d withdrawal period antemortem. The Federal Drug Administration (FDA) approved label claims of increased rate of BW gain, improved feed efficiency, and increased carcass leanness. Before the release of ZH for commercial use in 2007, approximately 10 independent research trials at various universities and commercial feedlots were initiated. Articles in recent issues of the Journal of Animal Science are a result of the large comprehensive body of research designed to increase the understanding of the effect of ZH on beef cattle growth, carcass traits, and beef quality. The feeding of ZH for 20 to 40 d with a 3-d withdrawal resulted in significantly increased ADG. The increases equate to an average of 9 kg heavier BW in ZH-fed steers. Hot carcass weight has been shown to increase to a larger degree compared with BW, with an average improvement of 15 kg. Dressing percent is increased by 1.5 to 2.0% with the feeding of ZH. Increases in carcass leanness were reported for cattle fed ZH mainly through a reduction in yield grades. The LM area was increased, along with yield of subprimal cuts from the round, flank, and loin. Warner-Bratzler shear force studies have shown LM steaks from ZH-treated cattle to have increased shear force values of 1.1 to 1.7 kg for 7-d-aged steaks, 0.4 to 1.3 kg for 14-d-aged steaks, and 0.27 to 1.4 kg for 21-d-aged steaks compared with controls. Recent research has suggested that the aging response is normal in ZH steaks. Consumers were able to identify tenderness differences in 14-d-aged Choice steaks from cattle fed ZH for 20 d compared with 14-d-aged steaks from control cattle; this difference was mitigated with 21 d of postmortem aging. Zilpaterol hydrochloride has been shown to increase cattle growth and efficiency as well as lean tissue deposition in the carcass, with some impact on carcass traits such as Warner-Bratzler shear force.
R J Delmore; J M Hodgen; B J Johnson
Publication Detail:
Type:  Journal Article; Review     Date:  2010-04-09
Journal Detail:
Title:  Journal of animal science     Volume:  88     ISSN:  1525-3163     ISO Abbreviation:  J. Anim. Sci.     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-07-13     Completed Date:  2010-10-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8003002     Medline TA:  J Anim Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2825-8     Citation Subset:  IM    
Animal Science Department, California Polytechnic State University, San Luis Obispo 93407, USA.
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MeSH Terms
Animal Husbandry / methods
Cattle / growth & development*
Food Additives / pharmacology*
Meat / standards*
Trimethylsilyl Compounds / pharmacology*
United States
Weight Gain / drug effects
Reg. No./Substance:
0/Food Additives; 0/Trimethylsilyl Compounds; 0/Zilpaterol

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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