Belgian Blue

Belgian Blue is a beef cattle breed developed in central and northern Belgium from the nineteenth century onward, known for an extreme degree of muscle development called double muscling, caused by a mutation in the myostatin gene that suppresses a natural limit on muscle growth. The result is an unusually lean, heavily muscled carcass with a high proportion of saleable meat relative to bone and fat, a trait that made the breed valuable for crossbreeding onto other cattle to improve beef yield. Because double-muscled calves are often too large to be born without assistance, Belgian Blue cows frequently require caesarean delivery, a management cost that has drawn criticism on animal welfare grounds. The breed is farmed both as a purebred beef animal in Belgium and as a terminal sire crossed onto other breeds in many cattle-producing countries.