Myostatin-related muscle hypertrophy (”double muscle”) is a condition that is still somewhat new to scientific scrutiny, and as mentioned until 2000, was not adequately documented as occurring in humans. Before this time, the best known example was that from ridiculously buff Belgian Blue cattle
Belgian Blue Cattle....when scientist get a hold of an animal, I just can't favor this kind of thing. I love science, but let the animal be normal. Crossbreeding is fine, unless you are messing with gene implantation, artificially, or adding or removing something. In my opinion, that behavior comes from greed at the animals' expense.
Belgian Blueis a breed of beef cattle from Belgium. The Belgian Blue's sculpted, heavily muscled appearance is known as "double-muscling". The double-muscling phenotype is a heritable condition which results in the increased ability to convert feed into lean muscle, which causes these particular breeds' meat to have a reduced fat content.