Abstract
Half carcasses of 18 Pietrain and 18 Large White female pigs were each dissected into 93 muscle units. An allometric analysis of the weight of these units relative to total muscle revealed increasing craniocaudal and distoproximal growth gradients, which were more pronounced in the Pietrain.The greater total weight of muscle, shown previously for the Pietrain at any given body weight over the range studied, was not due to higher muscle weights in any particular region at birth, but at 60 kg body weight was due to heavier high impetus muscles. Heart weight relative to total muscle weight was higher for the Large White over the entire range.It is concluded that for the animals studied the changes in muscle distribution are related to the functional demands of an increase in body size, and that the muscle distribution of pigs can differ between breeds.