Four groups of calves (10 bulls, 10 steers, 10 heifers and 10 ovariectomized heifers) of Simmental- Hereford breeding were individually given a high-energy diet from 10 to 16 months of age. At the end of the experiment, the 9-10-11th rib section was dissected into fat, lean and bone and chemical analysis was performed on the dissected soft tissue. For each group, the relationship between food intake and change in body weight was examined by a method designed to separate intake into its simultaneous maintenance and gain components: least-squares estimates for the maintenance coefficient (βm, kg/day per kg body weight) and the gain coefficient (βg, kg food per kg gain) were obtained for each animal. Conventional measures of food conversion ratio (kg food per kg gain) were examined on both common age and common weight-gain bases. Bulls, followed by steers, accumulated the most lean and least fat while heifers and ovariectomized heifers accumulated the least lean and most fat. Maintenance coefficients (βm) were lower in males than in females but did not differ within gender. Gain coefficients (βg) did not differ among the groups, although the coefficients appeared to be similar within gender. Food conversion ratio computed over a common age interval did not differ among groups. Food conversion ratio computed over common weight intervals was lowest in bulls followed in increasing order by steers then the two female groups. It is concluded that males grow more efficiently than females while accumulating more lean and less adipose tisue and that this greater efficiency is achieved by consuming less food per unit of body weight for maintenance, leaving proportionately more of the total intake available for gain.