Analysis of longissimus dorsi muscles from cattle implanted with hexoestrol.

It is now well established that the effect of synthetic oestrogens (administered orally or implanted as pellets) in enhancing the rate of weight gain in cattle and sheep is associated with a decrease in the percentages of subcutaneous, perinephritic and intermuscular fat. There is a concomitant increase in the percentages of bone and edible meat, the latter having an apparently higher moisture content (Burris, Bogart, Oliver, Mackey & Oldfield, 1954; Lamming, 1956; Bindloss, 1958). Despite certain reports that the muscles from implanted animals are ‘dark-cutting’, little attention has been given to the more detailed composition of the lean meat from implanted animals. The available analytical data refer almost exclusively to joints (Burris et al. 1954; Wierbicki, Kunkle, Cahill & Deatherage, 1956; Gee & Preston, 1957; Davey & Wellington, 1959). In the present paper a brief account is given of the effects of implantation in steers on the composition of the longissimus dorsi muscle.