Abstract: | The relative effectiveness of implanting 300 mg trenbolone acetate alone or in combination with either 15, 30 or 45 mg hexoestrol was studied in three 90-day experiments using 64 Friesian steers. In experiment 1 hexoestrol was shown to improve live-weight gain and efficiency of feed conversion in steers implanted with trenbolone acetate. In experiments 2 and 3 trenbolone acetate in combination with 30 mg hexoestrol gave a better growth response than when combined with either 15 or 45 mg. However, in experiment 3 trenbolone acetate plus 15 mg hexoestrol was shown to improve live-weight gain by about 36 per cent compared with untreated controls. In experiment 2 small differences between treated groups in mean values for plasma urea, serum albumin, plasma glucose and free fatty acids were recorded. |