Candidate genes for carcass traits in a tropical-adapted Brazilian composite beef breed.

Backfat thickness (BFT) and ribeye area (REA) are important production traits but, because they are measured late in the animal's life, they have not been efficiently included in breeding programs. The aim of this study was to evaluate whether single nucleotide polymorphisms (SNPs) mapped to the leptin, PPARGC1A, PSMC1, CRH, and FABP4 genes, which influence BFT and REA in Canchim cattle, a composite beef breed (5/8 Charolais + 3/8 Zebu). BFT and REA phenotypic records were obtained by ultrasound measurements from 18-month-old animals. All SNP markers were genotyped by restriction fragment length polymorphism-polymerase chain reaction. Restricted maximum likelihood analysis revealed that the non-synonymous SNP located in exon 2 of the FABP4 gene has an additive effect on BFT (P ≤ 0.05). Significant allele substitution effects showed that the substitution of G by A may lead to a decrease of 0.1055 mm in mean BFT. This information can be used for inclusion of this trait-associated marker in commercial SNP panels.