Association of single nucleotide polymorphisms in CAPN1 and CAST genes with beef tenderness from Spanish commercial feedlots

Frequencies of two SNPs in the mu-calpain (CAPN1) and calpastatin (CAST) genes in local and foreign commercial cross-breeds used in south-western Spain (Charolais, Limousin, and Retinta) were evaluated and the association of these markers with texture analysis in animals fattened under different feedlot conditions was assessed. Marker frequencies were estimated in a 286 bull crossbred population and the longisimus dorsi muscles from subsequently selected 161 animals were used to measure Warner-Bratzler shear force in raw and cooked samples at three different ageing days (1, 7, and 21). Significant differences (P <= 0.05) were found for shear force in raw and cooked meat samples for the three ageing days for the three crossbreeds analyzed. Significant associations were observed for raw meat for the Charolais between shear force and the CAPN1 marker (P = 0.019), as well as between the CAST polymorphism and shear force (P = 0.027) in the Limousin. No associations were found between the markers and shear force in the Retinta (P> 0.05). In contrast, although these markers might be useful in particular selected populations due to their effect on objective texture parameters, no significant association (P > 0.05) was found for cooked meat in the sample of Spanish commercial crossbreeds used in this study. Further studies with a higher number of animals will be necessary to confirm these results.