Assessment of GH1, CAPN1 and CAST polymorphisms as markers of carcass and meat traits in Bos indicus and Bos taurus–Bos indicus cross beef cattle

The objective of this study was to investigate the effects of bovine GH1, CAPN1 and CAST gene polymorphisms on carcass and meat traits in Nellore and Nellore x Bos taurus beef cattle. Three hundred animals were genotyped for GH1/MspI (TC/G in intron 3), CAPN316 (AF_252504.2:g.5709C > G) and CAST/RsaI (AY_008267.1:g282C > G) and phenotyped for rib eye area, backfat thickness, intramuscular fat, shear force (SF), and myofibrillar fragmentation index (MFI). No significant associations were observed between the GH1/MspI and CAST/RsaI polymorphisms and phenotypes, although the relation between the CAST/RsaI genotypes and meat tenderness evaluated by MFI approached significant. The fact that the CAPN316 polymorphism did not show adequate segregation in Nellore cattle confirms the difficulty of using this marker in breeding programs of different Bos indicus breeds. However, the positive results of the association analysis obtained for Nellore x B. taurus crosses contributed to the validation of previous findings.