The effect of hexoestrol on nitrogen retention of lambs and on ration digestibility

Abstract

It is now widely accepted that the subcutaneous implantation of stilboestrol or hexoestrol increases the rate of live-weight gain in lambs and cattle. In sheep it is generally considered that for a feeding period of up to 12 weeks a single implantation of hormone produces an adequate growth response. Perry et al.(1951), Stephens & Thompson (1952) and Bell et al.(1954) reported no advantage from repeated implantations during the experimental period. In a series of experiments at this Institute (Preston & Gee, 1957a) it has been noticed that the major part of the increased weight gain takes place during the first six weeks after hexoestrol implantation.