U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



Published in Beef Research Program Progress Report (1982) No. 1: 29-30


Bulls were shown to grow more rapidly (+18%) and convert feed to live weight gain more efficiently (22% less feed) when compared to steers. Whereas bulls had larger loin eye areas and yielded a higher percentage of major retail cuts, marbling scores and quality grades were similar for bulls and steers. Implants containing estradiol-17β dipropionate had no major effects on performance characteristics of steers but reduced the performance of bulls to approximately that of steers. Our research shows that estradiol can suppress performance of feedlot bulls by inhibiting testosterone secretion from the testes.