Sub-gastrocnemial ischemic myopathy in broiler breeders.

Five male broiler grandparent males developed lameness early in the breeding period. The lameness was shown to be due to a myopathy affecting muscles deep to the gastrocnemius. It is believed that the condition was precipitated by the vigorous activity associated with mating. Similarities to previously reported pectoral myopathy of chickens and other exercise-induced myopathies were noted.