The effect of a combination of trenbolone acetate and oestradiol-17β on growth performance and blood, carcass and body characteristics of wether lambs

Abstract

Nine Cheviot × Shetland castrated male lambs from a group of 24 of 28 kg initial live weight, were subcutaneously implanted with a combination of 60 mg trenbolone acetate and 12 mg oestradiol-17β at 105 days and again at 45 days before slaughter. Of the remaining lambs, nine were untreated and six were slaughtered at the start of the experiment as part of a comparative slaughter procedure. The lambs treated with the anabolic preparation grew significantly faster (P < 0·05), converted food to live weight and estimated carcass gain more efficiently, had heavier carcasses which were larger, and had greater estimated gains for protein, moisture and ash. Implanted animals also tended to have a smaller deposition of carcass and kidney fat, but significantly heavier kidneys and less wool when the latter three weights were related to empty body weight. The mean values for plasma urea and serum total protein as indicators of protein metabolism were significantly decreased and increased respectively in treated lambs, but no other significant differences in blood metabolites and hormones were recorded. A significant increase in teat length of implanted lambs indicated the oestrogenic nature of the anabolic preparation.