Association of two single nucleotide polymorphisms in the calpastatin gene with tenderness under varying lengths of meat ageing in two native Spanish cattle breeds

The objective of this study was to validate the effect of the SNPs rs210072660 and rs109221039 of the calpastatin (CAST) gene on meat toughness in Longissimus thorcicis muscle aged for 1 d (+/- 0; short-term ageing), 8 d (+/- 1; medium-term ageing) and 15 d (+/- 2; long-term ageing). The samples were obtained in experiments with different management strategies in Parda de Montana (grazing and concentrate-fed bulls, grazing steers, and steers finished on a total mixed ration) and Pirenaica (concentrate-fed bulls, steers and heifers, and steers on a total mixed ration) cattle. In the Parda de Montana breed, the Warner-Bratzler Shear Force (WBSF) was similar among management strategies under short-term aging, but it was lower for concentrate-fed bulls than for grazing bulls under medium-term and long-term aging (P < 0.05), presenting both groups of forage-fed steers intermediate values. Similarly, there were no differences in the short-term ageing, but there were differences observed thereafter in the Pirenaica breed. Regarding the effect of SNPs of CAST in the Parda de Montana breed, WBSF was only affected by the interaction between the SNP rs210072660 and ageing (P < 0.05). Shear force did not differ among genotypes (P > 0.05) under short-term ageing, but the GG genotype had 14-16% greater WBSF than the GA and AA genotypes under medium-term ageing (P < 0.001), and a trend was found under long-term ageing (P = 0.07). In Pirenaica, WBSF was only affected by SNP rs109221039 (P < 0.001). The GG genotype showed higher WBSF than the GA and AA genotypes under medium-term and long-term ageing (P < 0.01). Haplotype analyses confirmed the association results. In the Parda de Montana breed, animals carrying no copies of haplotype AA had a greater WBSF under medium-term ageing than animals with 1 or 2 copies of this haplotype (P < 0.05). In the AG haplotype, animals with 0 copies of this haplotype had greater toughness than animals with 1 copy (P < 0.05). In Pirenaica breed, animals with 2 copies of the GG haplotype had greater toughness than animals with 1 or 2 copies in both ageing periods (P < 0.001). These findings suggest that SNPs rs210072660 and rs109221039 could be useful markers for effective marker-assisted selection to increase meat tenderness in the Parda de Montana and Pirenaica breeds, respectively.