ZIPATEROL  HYDROCHLORIDE

Zilpaterol (zilpaterol hydrochloride) is a beta-adrenergic agonist. Under its trade name, Zilmax, it is used to increase the size of cattle and the efficiency of feeding them.Zilmax is produced by Intervet, a subsidiary of Merck & Co., and marketed as a "beef improvement technology".Zilpaterol is typically fed in the last three to six weeks of cattle's lives, with a brief period (three days in the US) before death for withdrawal, which allows the drug to mostly leave the animal's tissues.

Concerns have been raised on the impact of zilpaterol on flavor;^[4] however, studies have confirmed that overall tenderness, juiciness, flavor intensity, and beef flavor remain within the normal variation observed in the beef industry and differences are smaller than what can be detected by the consumer However, several studies have shown the use of zilpaterol leads to increased size, feed efficiency, and value.

Merck reported Zilmax-fed cattle do not produce beef with a difference in taste or quality compared to cattle not fed the drug, but elsewhere, concerns have been raised about the beef's tenderness. Studies have variously found a slight reduction in tenderness, an increase in shear force and a lower percentage of intramuscular fat (marbling).

Processor adoption and bans

Tyson Foods was the first among the largest U.S. meatpackers to adopt Zilmax. Because of concerns about tenderness and loss of marbling, Cargill and other meatpackers resisted the practice. The next adopters were JBS and National Beef, with Cargill finally joining them in mid-2012

On August 6, 2013 Tyson Foods banned Zilmax-fed cattle from its processing plants after cattle began arriving with missing hooves in large numbers during hot weather

References

1.                        1     Jump up^ Verhoeckx KC, 1 Doornbos RP, Witkamp RF, van der Greef J, Rodenburg RJ (January 2006). "Beta-adrenergic receptor agonists induce the release of granulocyte chemotactic protein-2, oncostatin M, and vascular endothelial growth factor from macrophages.". Int Immunopharmacol. 6 (1): 1–7. doi:10.1016/j.intimp.2005.05.013. PMID 16332507.

2.                             ^ Jump up to:^a b c Petersen, Melody. "As Beef Cattle Become Behemoths, Who Are Animal Scientists Serving?". The Chronicle Review - The Chronicle of Higher Education. Chronicle.com. Retrieved 2012-04-16.

3.                             ^ Jump up to:^a b "Zilmax - Overview". Merck-animal-health-usa.com. Retrieved 2012-04-16.

4.                             Jump up^ "Why Beef Is Becoming More Like Chicken". Slate.com. Feb 14, 2013.

5.                             Jump up^ "ZILMAX (Zilpaterol Hydrochloride): Type A Medicated Article for Cattle Fed in Confinement for Slaughter".Freedom of Information Summary, Original New Animal Drug Application, NADA 141-258 (Food and Drug Administration).

6.                             Jump up^ A. Plascencia , N. Torrentera , and R.A. Zinn (1999)."Influence of the β-Agonist, Zilpaterol, on Growth Performance and Carcass Characteristics of Feedlot Steers". Proceedings, Western Section, American Society of Animal Science 50: 331–334.

7.                             . PMID 1909824

8 Delmore, R. J.; Hodgen, J. M.; Johnson, B. J. (2010). "Perspectives on the application of zilpaterol hydrochloride in the United States beef industry". Journal of Animal Science88 (8): 2825–8. doi:10.2527/jas.2009-2473.PMID 20382871.

9Jump up^ Lawrence, T. E.; Gasch, C. A.; Hutcheson, J. P.; Hodgen, J. M. (2011). "Zilpaterol improves feeding performance and fabrication yield of concentrate-finished cull cows". Journal of Animal Science 89 (7): 2170–5. doi:10.2527/jas.2010-3422. PMID 21278106.

10^ Jump up to:^a b Holmer, S. F.; Fernández-Dueñas, D. M.; Scramlin, S. M.; Souza, C. M.; Boler, D. D.; McKeith, F. K.; Killefer, J.; Delmore, R. J.; Beckett, J. L.; Lawrence, T. E.; Vanoverbeke, D. L.; Hilton, G. G.; Dikeman, M. E.; Brooks, J. C.; Zinn, R. A.; Streeter, M. N.; Hutcheson, J. P.; Nichols, W. T.; Allen, D. M.; Yates, D. A. (2009). "The effect of zilpaterol hydrochloride on meat quality of calf-fed Holstein steers". Journal of Animal Science 87 (11): 3730–8. doi:10.2527/jas.2009-1838.PMID 19648490.

11Jump up^ Leonard, Christopher (2014). The meat racket : the secret takeover of America's food business. New York: Simon & Schuster. ISBN 9781451645811.

12Jump up^ http://www.businessinsider.com/why-merck-halted-sales-of-zilmax-2013-12

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