The objectives of this study were to determine the efficacy of various doses of rbST on ADG and feed efficiency (FE) and to describe carcass composition changes in finishing beef steers. In Exp. 1, 96 crossbred beef steers (393 kg) received daily i.m. injections of buffer or 33, 100, or 300 micrograms/kg of BW of rbST (0ST, 33ST, 100ST, 300ST). In Exp. 2, 200 crossbred beef steers (417 kg) rece...

BACKGROUND Results regarding the use of bovine somatotropin for enhancing fertility in dairy cattle are variable. Here, the hypothesis was tested that a single injection of a sustained-release preparation of bovine somatotropin (bST) during the preovulatory period would improve pregnancy success of lactating dairy cows at first service. RESULTS The first experiment was conducted in a temperat...

The development of muscle in vitro from embryonic presumptive myoblasts is known to have complex nutritional requirements.' One of the necessary ingredients for myogenesis in vitro, and indeed for the growth of many cell types, is serum. During the course of studies aimed at understanding the mechanisms involved in the fusion of myoblasts, it became of interest to delete serum from the medium a...

The effects of dietary energy and recombinant bovine somatotropin (bST) on pattern of LH release, follicular development, and onset of puberty were studied in 40 Angus heifers. At 7 mo of age, heifers were assigned to a 2 x 2 factorial experiment; the main effects were dietary energy (high [HDE]: 14.15 Mcal of ME/d or moderate [MDE]: 10.84 Mcal of ME/d) and somatotropin (bST; 350 mg every 2 wk ...

This manuscript presents the results of a review of the effects of recombinant bovine somatotropin (rBST) on dairy cattle health, reproductive performance, and culling, that was carried out by an expert panel established by the Canadian Veterinary Medical Association (CVMA). The panel was established by the CVMA in response to a request from Health Canada in 1998 and their report was made publi...