if you get the test, they usually tell you which version.
All cattle breeders will be aware of double muscled cattle, particularly the Belgian Blue. This breed has been selectively bred for what is commonly known as double-muscling. This is the manifestation of a condition known as myostatin gene mutation.
www.beefshorthorn.org
There are nine known variants of the myostatin mutation:
C313Y common in the Piedmontese
E291X common in the Marchigiana
nt419 sometimes found in Shorthorns and occurs in the Maine Anjou
nt821 Belgian Blue, Blonde, Limousin and South Devon – the most common variant in the Angus
Q204X Charolais, Limousin
E226X – the most common variant found in the Shorthorn and the Maine Anjou
D182N
F94L found in Limousin and sometimes the Shorthorn
S105C
"At present there is little research into the variations of phenotype arising from any of these variants in the Shorthorn. In breeds like the Shorthorn where selection has historically been ‘balanced’, the effects of the mutation may be less pronounced than in other breeds. In addition, the mutations do not operate in isolation, but interact with other genes in ways that are, as yet, poorly understood. It is often observed that one copy of a variant does not necessarily give rise to a deleterious phenotype. There may, for example, be an increase in musculature without obvious signs of any disadvantageous side effects.
It is therefore inappropriate to take a simplistic approach and disqualify all cattle carrying a variant from the herd book. In addition, not all well-muscled Shorthorns will carry any of the mutations."
