EFFECTS OF BREED AND SEX ON THE RELATIVE GROWTH AND DISTRIBUTION OF BONE IN PIGS

Abstract

The growth and distribution of bone from 179 pig carcasses were compared among five breeds (Duroc × Yorkshire (D × Y), Hampshire × Yorkshire (H × Y), Yorkshire (Y × Y), Yorkshire × Lacombe-Yorkshire (Y × L-Y) and Lacombe × Yorkshire (L × Y)) and two sex-types (barrows and gilts) over a wide range in carcass weight. The growth pattern for each bone relative to total side bone was estimated from the growth coefficient, b, in the allometric equation (Y = aXb). Growth coefficients were homogeneous in this study among breeds and between sexes for each bone, indicating that the different breeds and sexes followed similar patterns of relative bone growth as they increased in size. The lowest growth coefficients (b < 1.0) were found among the limb bones (tarsus, femur, and radius/ulna). The thoracic vertebrae, carpus, tibia, humerus, sternum, pelvic and pectoral girdles had growth coefficients not significantly different from 1.0, while the ribs, lumbar and cervical vertebrae, patella and atlas had growth coefficients significantly greater than 1.0. Significant breed and sex differences were found in the weights of individual bones when adjusted to equal side bone weights. However, these were small and may reflect differences in stage of skeletal maturity.