Effects of severe food restriction on bone growth and distribution in pigs

Abstract

SummaryThe effects of food restriction on the growth and distribution of bone and on the relation between changes in long bone lengths and changes in limb muscle proportions were studied in 32 Duroc Jersey barrows. Sixteen pigs were fed ad libitum (H group) whilst the other 16 received the same diet on a restricted scale related to live weight.Animals in each group were slaughtered at times such that the weights of bone in their half carcasses were spread evenly over the range 1·5–4·O kg. The right half carcasses were completely dissected using strictly anatomical criteria.The results on the relative growth of bone were examined by covariance analysis using the allometric equation.After adjusting for equal weight of total bone in the side L pigs had heavier femur, tibia-fibula, humerus and radius-ulna and lighter scapula and ribs than H pigs.Relative to their weights all appendicular long bones were longer in L pigs than in H ones, while there was no such effect on spinal column length.The effects of the treatment on fore limb muscle proportions relative to total muscle were significantly correlated (P < 0·01) with the changes observed in the lengths of the long bones forming their osseus bases. However, in the case of the hind limb the regression and correlation coefficients were not significantly different from zero.