The effect of hexoestrol implantation on the fattening of lambs.

The subcutaneous implantation of stilboestrol pellets in ewe and wether feeder lambs has been shown to result in a faster rate of gain in weight (Andrews, Beeson & Harper, 1949; Jordan, 1950; O’Mary, Pope, Wilson, Bray & Casida, 1952; Means, Andrews & Beeson, 1953 ; Andrews & Beeson, 1953 ; Bell, Smith & Erhart, 1954; Clegg, Albaugh, Lucas & Weir, 1955). With from 12 to 36 mg stilboestrol the increase in the daily gain in weight ranged from 0.024 to 0.255 lb. Stilboestrol was usually given by one implantation; when a second implantation was made there was no significant additional increase in the rate of gain in weight. The object of the present trial was to find the effect on the gain in weight of fattening lambs of a single subcutaneous implantation of 15 mg hexoestrol, another synthetic oestrogen closely related to stilboestrol.