The effect of dose and method of administration of recombinant bovine somatotropin on fleece growth and body composition in young, fattening lambs

Abstract

Daily injections of bovine pituitary somatotropin (growth hormone) can markedly increase growth and muscle deposition in fattening lambs, although the optimal dose range for these effects is not known.This experiment was designed to assess the anabolic and lipolytic activities of biosynthetic somatotropin (produced by genetically-modified bacteria) in fattening lambs, and to determine the effects of dose and method of administration.Dorset Down x Finn-Dorset lambs were individually penned, fed a barley/soyabean meal diet ad libitum (C.P.=155g/kg DM) and allocated to one of six treatment groups, each containing 5 ewe and 5 wether lambs, such that each group had the same initial mean live weight (18 kg). Between 10 and 21 weeks of age, the lambs of each group received one of the treatments shown in Table 1, comparing 3 doses of somatotropin (0.025, 0.1 or 0.25 mg/kg live weight), dissolved in bicarbonate buffer and injected subcutaneously once each day, with the intermediate dose (0.1 mq/kg/day) given by continuous subcutaneous infusion or by daily subcutaneous injection as a suspension in olive oil.

The effects of short-term recombinant bovine somatotropin treatment on fattening performance, carcass composition and visceral organ weights in karayaka lambs in Turkey

“…Pelvic and internal fat tissue did not change in bST group. This finding is in agreement with previous studies (McLaughlin et al 1994;Godfredson et al 1990;Johnsson et al 1986;Muir et al 1983). Analysis of the carcasses showed some carcass components were affected by bST treatment.…”

“…Previous studies have reported that somatotropin treatment had little effect on growth, feed intake and feed conversion of lambs (Johnsson et al 1986). Similarly, ovine growth hormone (oGH) and recombinant bovine somatotropin did not alter average daily live weight gain and feed intake (Muir et al 1983;Bird et al 1996).…”

The effects of dose and method of administration of biosynthetic bovine somatotropin on live-weight gain, carcass composition and wool growth in young lambs

“…Preliminary results have been published previously in abstract form (Johnsson, Butler-Hogg, Hathorn and Wilde, 1986). Preliminary results have been published previously in abstract form (Johnsson, Butler-Hogg, Hathorn and Wilde, 1986).…”