Department of Animal Science


Date of this Version

January 2000


Published in Nebraska Beef Cattle Report 2000, published by Agricultural Research Division, University of Nebraska Cooperative Extension, and Institute of Agriculture and Natural Resources, University of Nebraska–Lincoln.


In a 110-d experiment, feedlot heifers (mean initial weight = 820 lb) that received an estradiol benzoate (EB) + trenbolone acetate (TBA) implant, Synovex® Plus™, gained faster and more efficiently than sham-implanted (control) heifers. Heifers that received only TBA implants had lower intakes and lower quality grades than control heifers, but were more efficient in feed conversion than control and EB implanted heifers. On the basis of improved yield grade and larger ribeye areas, along with no increases in fatness, the combined use of EB and TBA provided for greater quantities of lean meat from higher priced cuts than did control or other implant groups.