Condition of sows during reproductive activity depending on lipid metabolism gene (DGAT1) polymorphism

Mutations at gene loci associated with body lipid metabolism may affect not only carcass and meat quality traits in young animals but also the production results of mother sows. The objective of the study was to determine the effect of mutations in the DGAT1 gene, found in Polish populations of maternal breeds, on condition of gilts and later on condition and reproductive performance of sows during three reproductive cycles. The study involved 118 gilts of maternal breeds (Polish Large White (PLW ) and Polish Landrace (PL)). Gilts and subsequently sows were monitored for body weight (BW) and P2 backfat thickness over three reproductive cycles and their litters were analysed for the number and body weight of the piglets. A total of 354 litters of pigs were evaluated. In the analysed pig populations, a single mutation (A/G) in the DGAT1 gene (rs45434075) had a significant effect on deposition of subcutaneous fat only in the PLW gilts (P2_G, AA,AG<GG P≤0.05 and P2_F r=214 P≤0.01). As regards the G/A 3’UTR polymorphism of the DGAT1 gene (rs342152658), this mutation is negatively correlated only in the PL sows with fatness during their reproductive life and with BW of the piglets reared to 21 d of age. Sows of the DGAT1^GG 3’UTR genotype had significantly lower P2_F backfat thickness (P≤0.05) and, during a 21-d lactation, reared lighter piglets (P≤0.01) compared to sows of the same breed with the DGAT1^AG 3’UTR genotype. The analysed traits were also affected by the interaction between mutations in the DGAT1 gene of the sows of maternal breeds (DGAT1/DGAT1 3’UTR). Sows of the DGAT1^GG/GG genotype were characterised by the highest backfat thickness on selection day, and during three reproductive cycles they reared significantly more piglets compared to sows of the DGAT1^AA/AG genotype. Heterozygous sows (AG/AG) reared significantly heavier piglets than sows of the AA/GG and AG/GG genotypes (P≤0.05).