Double-muscling historically has also been known as myofibre hyperplasia, doppellender, muscular hypertrophy, a groppa doppia, and culard.
[1] Some breeds of cattle do not possess the myostatin gene that helps regulate muscle growth.
During this research he noted the loss of white fat that occurred when hyper muscularity by myostatin would happen.
"Dr. Lee has shown that other molecules in the TGF-B pathways, notably the activins and follistatin, also regulate muscle mass.
"The research has produced several muscle-building drugs now being tested in people with medical problems, including muscular dystrophy, cancer and kidney disease.
[7] "There is a persisting trend to improve carcass quality in specialized beef breeds.
"[7] Scientific studies have found that calving ease and birth weight can in some cases be negatively impacted where both parents carry the double-muscling genes, leading to difficulty of calving and in some breeds a ~20% increased likelihood of birth by cesarean section being required.