MSD Zilmax (Zilpaterol) is a feed mix used in cattle to increase muscle mass, improve feed efficiency, and increase carcass weight in animals. Works by redirecting the animal’s energy to build more lean muscle and less fat. Fed to cattle during the last 20-40 days of their feeding period. Not for use in pigs, lambs, goats, or horses. 

• Increases muscle growth and weight: Zilmax helps cattle gain more weight, with an average increase of about 30 lbs in hot carcass weight.
• Improves feed efficiency: It makes the cattle more efficient at converting feed into muscle, leading to a slight improvement in feed efficiency.
• Enhances carcass quality: It can result in a larger ribeye area and a slight reduction in backfat thickness.
• Requires a withdrawal period: Zilmax-fed cattle need a minimum three-day withdrawal period before slaughter.
• Administered in late-stage feeding: It is used for market steers and heifers to maximize muscle deposition and reduce fat.