Cutting yields and tissue composition of the cows are shown in Tables 8 and 9. Testosterone treatment did not influence proxi- mate composition. However, time on feed did influence proximate composition (P < .05). The initial soft tissue fat content of 9.0% is indicative of the nutritional state of the cows at the start of the experiment. Soft tissue weight increased (P < .05) with each feeding period, as would be expected based on live and hot carcass weights. Total carcass weight (trimmed) increased by 66.7 kg after 84 d; 35.3 kg (53%) of that increase was fat. Swingle et al. (1979) noted that 51.7% of the weight gain of cows fed 63 d was lipid and 13 and 35.3% of the gain was protein and moisture, respectively. Matulis et al. (1987) found that 56% of the 43.4-kg increase in soft tissue weight was lipid in cows fed for 84 d.