Associations of QTL Region Genes of Chromosome 2 with Meat Quality Traits and Productivity of the Ukrainian Large White Pig Breed

In recent decades, selection in pig farming has been aimed at obtaining animals with a high growth rate and increased meat yield in the carcass, resulting in a tendency for deteriorated quality characteristics of pork. One way to solve this problem is to develop genetic markers of pig meat quality and to use them in breeding programs along with the markers of other productive traits. The article presents the results of the analysis of the association of genes IGF2 (SNP g.3072G > A), CTSD (SNP g.70G > A), and CTSF (SNP g.22G > C) localized in the QTL region of the distal end of the p-arm of chromosome 2, with the meat quality traits and carcass structure in pigs of the Ukrainian Large White breed (ULW). According to these SNPs, all genes were characterized by a high level of polymorphism (PIC = 0.343–0.371). The association of CTSD (SNP g.70G > A) with the content of intramuscular fat ( p = 0.02), moisture content in meat ( p = 0.03), and its moisture-holding capacity ( p = 0.03) was established. CTSD (SNP g.70G > A) also had an additive effect on an important selection trait: the backfat thickness ( p = 0.05); it was the highest in pigs of the g.70GG genotype. Associations of CTSF (SNP g.22G > C) with the moisture content in meat ( p = 0.01) and IGF2 (SNP g.3072G > A) with the moisture loss from meat during heat treatment ( p = 0.01) were revealed. The polymorphisms of the studied genes can be used as genetic markers in marker-associated selection of the Ukrainian Large White pig breed.