BCRC 3 - Development of DNA markers for beef quality

Summary

​Meat and carcass quality are commercially important traits of beef cattle but meat quality in particular has proved to be hard to improve using genetic methods. One option is to identify DNA markers that could be used to predict breeding values or phenotypes. In this study, we used the genome wide association methodology to identify likely genes affecting meat and carcass quality.  The traits of most interest were marbling or intramuscular fat percent (IMF), meat tenderness (LLPF) and meat yield (RBY) and rump fat tickness (P8FAT). We have performed two genome wide association studies, the most recent using 54,000 DNA markers on 1,035 cattle with meat and carcass quality phenotypes associated with the Beef CRC DNA bank and database. So far, 279 highly significant (P < 0.001) associations for the four traits were identified, more than would be expected by chance. Several of these associations have now been confirmed in large independent studies. The largest confirmed effect accounts for 2.2% of the residual phenotypic variance in rump fat thickness, this was larger than the combined effect of the Calpain and Calpastatin genes for meat tenderness in the same type of cattle, and it was the largest gene effect reported so far for meat or carcass quality, after the myostatin double muscling mutation. Four genes have been confirmed that each explain as much variability for IMF as Calpain or Calpastatin explain for meat tenderness and should be made available for commercial release as genetic tests.