Genetics of seam fat in cattle

Abstract

As far as most consumers are concerned, a good steak is a steak with visibly desirable colour (doneness), a large portion of muscle and a small amount of fat, especially the seam fat located between the muscles. During the intensive growth to commercial slaughter weights in feedlots, there is a distinct change in the composition of the body with the amount of fat increasing and the musculature remaining reasonably constant (Pitchford and Bottema, 2000). Cattle breeds deposit fat at different rates and in different locations (subcutaneous, intermuscular or intramuscular). For example, early maturing Jersey cattle deposit more fat intramuscularly than late maturing Limousin cattle (Pitchford and Bottema, 2000). These differences suggest that there is a genetic basis for fat distribution. The aim of this study was to investigate the genetic variation in seam fat distribution within loin muscles of Jersey and Limousin cross cattle, independent from carcass size and fatness.