Additive and Dominance Effects of MC4R and PIT1 Polymorphisms on Production and Carcass Traits in Duroc Pigs

Abstract

This study aimed to estimate the allelic and genotypic frequencies of single nucleotide polymorphisms (SNPs) of MC4R (melanocortin-4-receptor gene) and PIT1 (pituitary specific transcription factor-1) genes, and their additive dominance genetic effects on production and carcass traits in Duroc pigs. A total of 2170 tail tissue samples (1728 gilts and 442 male pigs) were collected from Dabaco Nucleus Breeding Pig Company, Bac Ninh province, Vietnam from January 2017 to June 2020. Polymorphisms in the MC4R and PIT1 genes were detected using the PCR-RFLP method. For MC4R, the frequencies of alleles A and G were 0.430 and 0.570, respectively. For PIT1, the frequencies of alleles A and B were 0.460 and 0.540, respectively. The genotype frequency distribution of the MC4R gene was in Hardy-Weinberg equilibrium (P = 0.375), but the genotype frequency distribution of PIT1 (P <0.001) was not. The MC4R and PIT1 polymorphisms were significantly associated with final body weight and average daily gain (P <0.001). Significant additive effects were also found (P <0.05) for the two traits. The selection of individuals with the MC4R genotype AA and PIT1 genotype AA could improve final body weight and average daily gain in Duroc pigs.