A DdeI polymorphism in the growth hormone gene is associated with higher lean meat yield and pH 45 min in postmortem pigs
Marker-assisted selection has been widely used in breeding programs. The use of single nucleotide polymorphisms (SNPs) as genetic markers enables identification of genotypes that best contribute to quantitative characteristics. We evaluated a possible association between the DdeI growth hormone gene polymorphism and meat and carcass traits. A total of 476 halothane-free animals were genotyped. Animals originated from the crossing of an AGIPIC®415 male with Large White (LW) x Landrace (LD) females. Males were castrated when young and males and females were slaughtered between 150 and 180 days old. Hot carcass weight, carcass length, pH 45 min , and pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, and color by the CIELAB system were measured and the percentage of lean meat was calculated. Water holding capacity was determined by the filter paper method in the Semimembranosus muscle. A 605-base pair (bp) amplicon was obtained by PCR and a DdeI polymorphism was genotyped and two alleles identified, D1 with 335, 148, and 122 bp and D2 allele with 457 and 148 bp. Allele frequencies were 0.43 for D1 and 0.57 for D2. Genotypic frequencies were as follows: D1D1 (22.1%), D1D2 (49.8%), and D2D2 (28.1%). The Chi-Square test showed that the population was in Hardy-Weinberg equilibrium. The results of hot carcass weight, carcass length, pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, color and water holding capacity did not differ significantly among the genotypes. The DdeI SNP was associated with lean meat percentage and pH at 45 min posmortem in the Longissimus cervicis muscle; properties that are important for the commercialization of fresh meat as well as processed products.