Source: Rita Jane Gabbett, MEATINGPLACE, 6/16/16


A study published by University of Nebraska researchers on the animal welfare impacts of the growth promotant zilpaterol on finishing steers showed no discernable differences when steers were kept in the shade versus open pens.

Zilpaterol, formerly marketed by Merck Animal Health as Zilmax, was approved for use in beef cattle in the United States in 2006, but Merck pulled it off the market in 2013 after Tyson Foods, then other cattle processors, boycotted cattle fed the stimulant due to animal welfare concerns, particularly its impacts on heat stress.  

The research report, titled “Effects of Shade and Feeding Zilpaterol Hydrochloride to Finishing Steers on Performance, Carcass Quality, Heat Stress, Mobility, and Body Temperature,” showed no real differences among cattle fed the growth promotant between those raised in shade and those in open pens.  

The study evaluated the effects of shade and feeding zilpaterol hydrochloride on performance, carcass quality, mobility, and body temperature.

No effect on body temperature or performance was observed for shaded cattle versus cattle in open pens. Feeding zilpaterol increased carcass weight and lean mass, while decreasing yield grade, the study showed.  

“Zilpaterol hydrochloride increased respiration rate but did not significantly affect body temperature or mobility. Across all treatments mobility decreased with time, therefore, cattle were least mobile at the time of harvest,” the researchers wrote.

Researchers included: Bradley Boyd, Steven Shackelford, Kristin Hales, Tami Brown- Brandl, Meredith Bremer, Matthew Spangler, Tommy Wheeler, David King and Galen Erickson.

For more stories, go to www.meatingplace.com.