Girish Mahajan (Editor)

Zilpaterol

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Trade names
  
Zilmax

ATC code
  
none

PubChem CID
  
9992825

Pubchem
  
9992825

Trade name
  
Zilmax

Routes of administration
  
Oral

CAS Number
  
117827-79-9

Molar mass
  
261.148 g/mol

ChemSpider ID
  
2343170

Zilpaterol httpsmediascbtcomproduct0970z97052jpg

Biological half-life
  
11.9–13.2 hours (first phase)

Excretions
  
Urine (88.2–84.3%), Feces (in cattle, 8.6–8.7%)

What does zilpaterol mean


Zilpaterol (zilpaterol hydrochloride; codenamed RU 42173) is a β2 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.

Contents

Concerns have been raised on the impact of zilpaterol on flavor; 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).

Zilmax zilpaterol hydrochloride crystal farmer capstone summer 2012


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.

This drug is banned in China, Taiwan, Russia, and many countries in the European Union.

Chemistry

Zilpaterol has two chiral carbons and consequently four optical enantiomers. These enantiomers are: (6R,7R)-, (6R,7S)-, (6S,7R)- and (6S,7S)-. RU 42173 corresponds to racemic trans-zilpaterol hydrochloride, a mixture of the (6R,7R)-(−)- and (6S,7S)-(+)-enantiomers.

References

Zilpaterol Wikipedia