Editing Belgian Blue (section)

== Characteristics ==

The Belgian Blue has a natural [[mutation]] in the [[myostatin]] gene which codes for the protein, [[myostatin]] ("myo" meaning muscle and "statin" meaning stop).<ref name="entrez">{{cite web | title = Entrez Gene: Double muscling in cattle due to mutations in the myostatin gene| url = https://pmc.ncbi.nlm.nih.gov/articles/PMC24998/}}</ref><ref name=Kambadur />  Myostatin is a protein that inhibits muscle development. This mutation also interferes with fat deposition, resulting in very lean meat.<ref name=Kambadur /> The truncated myostatin gene is unable to function in its normal capacity, resulting in accelerated lean muscle growth. Muscle growth is due primarily to physiological changes in the animal's muscle cells (fibres) from hypertrophy to a hyperplasia mode of growth. This particular type of growth is seen early in the fetus of a pregnant dam, which results in a calf that is born with two times the number of muscle fibres at birth than a calf with no myostatin gene mutation.<ref name=Kambadur /> In addition, a newborn double-muscled calf's birth weight is significantly greater than that of a normal calf.<ref name="De Smet"/>

Belgian Blue cattle have improved [[feed conversion ratio]] (FCR) due to lower feed intake compared to weight gain<ref name="De Smet" />  due to an altered composition of body weight gain which includes increased protein and decreased fat deposition.<ref name="De Smet" /> The Belgian Blue's bone structure is the same as normal cattle, albeit holding a greater amount of muscle, which causes them to have a greater meat to bone ratio. These cattle have a muscle yield around 20% more on average than cattle without the genetic [[myostatin]] mutation.<ref name=Kambadur /> Because of this breed's increased muscle yield, a diet containing higher protein is required to compensate for the altered mode of weight gain.<ref name="De Smet" /> During finishing, this breed requires high-energy (concentrated) feeds, and will not yield the same results if put on a high-fibre diet.<ref name="De Smet" />