The increase in skeletal muscle mass in male and female mice

The total mass of skeletal muscle in male and female mice of strain 129/Re was found by removing the muscle from the bones using papain. The total muscle mass of male and female mice of under three weeks of age was not significantly different. After this time the muscle mass of male mice increased more rapidly and plateaued at a higher value than that of females. However, if the total muscle mass was plotted as a function of body weight then there was no significant difference between males and females. The percentage of body weight taken up by skeletal muscle was the same for males and females at all stages of development.