The effect of hexoestrol on growth, carcass quality, endocrines and reproductive organs of ram, wether and female lambs

Abstract

1. Two experiments were made. In Experiment 1, 124 ram, wether and ewe lambs were allocated to four equal groups as they reached a live-weight of 30 lb. Group A received no hexoestrol; group B were implanted with a 15 mg. pellet of hexoestrol and lambs of group C were given a second pellet of 15 mg. 35 days after the first. Group D were implanted with three 5 mg. pellets simultaneously in three different sites. The lambs were creep-fed while running with their dams on pasture and were killed as they reached a live-weight of 95 lb.In Experiment 2, 20 weaned ram lambs were allocated to a hexoestrol-implant group or a control group as they reached a live-weight of 40 lb. They were fed a pelleted ration indoors and were slaughtered at a live-weight of 110 1b.2. Length of teats and weight of the pituitary were significantly increased for all lambs treated with hexoestrol as compared with their controls. Excessive mammary development and one case of rectal prolapse were observed i n treated ewe lambs, while 3 of the treated rams in Experiment 2 had scrotal oedema.3. The rate of live-weight gain was greater for all hexoestrol-implanted lambs in Experiment 1 but less for the implanted lambs on Experiment 2 as compared with their respective controls. The differences just failed to attain significance at the 5% level.4. Dressing percentage was significantly reduced by hexoestrol treatment i n Experiment 1. On the other hand treated ram lambs in Experiment 2 had significantly higher dressing percentages and appeared to be fatter than the controls.5. Weights of testes and seminal vesicles in the ram and of the ovary in the ewe were decreased by hexoestrol treatment. Weights of seminal vesicles in the wether and of oviducts and uterus in the ewe were increased.