Growth, development and chemical composition of the pig. III. Bone, ash and moisture.

Growth and development of bone and the ash and moisture contents in the body of the growing pig were studied in a group of 90 animals, representing 12 weight groups and a live weight range of 10-132 kg. The average daily increase in body moisture was more rapid in the 10-34 kg animals than in subsequent weight groups. Beyond 34 kg the increase in moisture was more gradual and linear. The average daily gain of ash was almost linear over the weight range of 10 to 90 kg, but showed a decline from 90 to 132 kg. Length and width of the femur showed a similar growth pattern. From cross-sectional areas it appears that bone tissue develops somewhat faster in the shoulder and back than in the ham and loin. It is apparent from comparisons with growth curves reported in the literature that the animals used in the present study were much later maturing than those reported on during the thirties and forties. This could be the result of continued selection for leaner animals.