Genetic parameters and genomic insights for meat colour traits of Canadian crossbred beef cattle

Utilizing genomic tools in breeding programs accelerates genetic progress, particularly for difficult/expensive to measure traits such as meat colour. This study aimed to estimate genetic parameters and identify genomic regions and candidate genes associated with meat colour traits in Canadian crossbred beef cattle. Heritability estimates for lightness ( L * ), chroma ( c * ), and hue angle ( Hu) were 0.44, 0.20, and 0.57, respectively. L * and Hu were highly phenotypically (0.86) and genetically (0.98) correlated. The genome-wide association revealed a total of 30, 24, and 25 SNP windows explaining >0.5% additive genetic variance for L * , c * , and Hu, respectively. These SNP windows collectively explained >20% of the genetic variance for the three meat colour traits. The genes GNPDA2, CALCRL, CALM1, KIT, PRKN, and PRKAA2 are the most promising candidates associated with L * , TEX37, ADAMTS9, PRKACB, TTLL7, TFAM, AGT, ACAT2, and PPP1R3C with c * , and MMP2, AKR1B1, AKR1B10, and CYP7A1 with Hu. These candidate genes are mainly involved in energy metabolism pathways, among which the most important are glucose, fatty, and lipid metabolism.