Abstract
A recent development of much interest to the livestock farmer is the use of synthetic oestrogens in the production of beef and mutton. Numerous trials have proved that such hormones, implanted under the skin or fed in concentrates, not only increase the rate of liveweight gain in cattle and sheep but improve carcass quality and the efficiency of food conversion. The practice is already common in the U.S.A. and is spreading in the U.K.