Implanting Young Bulls With Zeranol for Meat Production

Abstract

Summary The benefits from implanting young bulls with zeranol (Ralgro®) for meat production appear to depend on the initial implanting age and the subsequent implanting schedule. Bulls implanted initially at weaning have shown few production advantages except for possible increases in average daily gain. In contrast, implanting bulls initially soon after birth and sequentially through slaughter enhances the feasibility of using bulls for meat production. Studies in which young bulls were implanted from near birth to slaughter reported reduced masculinity, scrotal development and behavioral interactions, and varied responses for average daily gain compared with non implanted bulls. These studies have also indicated decreased carcass masculinity, increased carcass fatness and marbling, improved tenderness, and reduced connective tissue (collagen) amount and maturation. By both a trained sensory panel and take-home consumer evaluation, bulls implanted from near birth to slaughter were similar to steers in flavor, tenderness and overall acceptability. Therefore, implanting young bulls with zeranol from near birth to slaughter may maintain performance traits similar to the nonimplanted bull, and improve palatability to a level comparable with the steer. For maximum benefit, implanting young bulls must be coupled with management techniques recommended for feeding young bulls for meat production.