Meat Tenderness Genetic and Genomic Variation Sources in Commercial Beef Cattle

To assess genetic group (GGR; Bos indicus [Bi], Bos taurus [Bt] and crosses [BtxBi]) and to confirm the calpain (CAPN316 and CAPN4751) and calpastatin (CAST-T1) single nucleotide polymorphism (SNP) effects on Warner-Bratzler shear force (WBSF), 196 animals under commercial conditions were analyzed. A model was fitted including the effect of GGR and considering residuals as adjusted WBSF (aWBSF). Another model was fitted to evaluate the SNP effect on aWBSF. Allele substitution effect () and combined favorable alleles in CAPN and CAST on aWBSF were evaluated. GGR showed a significant effect (P<0.0001) on WBSF; Bt and BtxBi had the lower WBSF. CAPN316 showed significant effect on aWBSF with an =-0.549kg. The combined effect of CAPN and CAST showed significant (P<0.0056) reduction on aWBSF of 0.239kg by favorable allele. The results remarked the importance of GGR and confirmed CAPN316 and combined effect of CAPN and CAST on prediction of meat tenderness. Practical ApplicationsKnowledge of main factors related to tenderness, as a key related factor to beef consumer satisfaction, would serve as a resource for commercial beef classification and management under slaughterhouse conditions. Confirmation on combined marker effects provides strong validation for marker-assisted management use of these technologies under industry conditions. Additionally, the presented results may be used as a reference for research in the beef industry aimed to provide improvement on beef tenderness to the final product.