The moderating effect of regular exercise on the development of nutritional muscular dystrophy in lambs

Abstract

Merino lambs have been weaned on to two types of dystrophogenic diet, one a synthetic-type dirt with selenium-low Torula yeast supplying most of the protein, and the other a natural diet consisting solely of selenium-low hay. Lambs not supplemented with selenium developed white muscle disease within two to three months on either regimen, some of the lambs dying within that period. Selenium, given at the rate of 2 X 3 mg per week as Na2 SeO3 as an oral drench prevented the onset of muscular dystrophy. When unsupplemented animals were subjected to daily exercise consisting of one-sixth to one-third of a mile canter in a treadmill each day from weaning, muscular dystrophy was either modified or delayed. In some cases it was entirely prevented over the experimental period. As judged by creatine phosphokinase levels in blood plasma, ECG records taken throughout the experiments, and histological examination of muscle post mortem, eight out of ten lambs in the non-exercised group developed white muscle lesions, compared with two out of ten in the exercised group.