Published online by Cambridge University Press: 06 May 2016
Subcutaneous implantation of the synthetic oestrogens, hexoestrol and stilboestrol is known to increase the daily rate of live-weight gain and to improve the efficiency of food utilisation in lambs (see review by Averill, 1955; Wilkinson et al., 1955; Gill et al.,1956; Jordan & Croom, 1956).
A critical review of these reports shows that despite the numerous experiments testifying to increased and more efficient weight gains as a result of implantation it is not known how much of this extra gain is represented by products saleable for human consumption. Further there is only limited information relating to the chemical composition of the increased live-weight and none concerning the precise nature of the increased efficiency of food conversion in units other than live-weight.