Short communication Effect of polymorphism in the LIF gene on reproductive performance of hybrid Polish Large White and Polish Landrace sows

The aim of the study was to determine the potential relationships between variants of the leukaemia inhibitory factor (LIF) gene and litter size in Landrace x Polish White sows. To identify polymorphisms within the LIF gene, the polymerase chain reaction–restriction fragment length polymorphism (PCR‒RFLP) method was applied, using specific primers and the DraIII enzyme. The researchers identified the presence of two alleles, T and C, with frequencies 0.64 and 0.36, giving three genotypes with frequencies of 0.44, 0.41 and 0.15, respectively, for TT, CT and CC. Analysis of relationships among the various genotypes of the LIF gene and selected reproductive traits showed differences. Sows with genotypes TT and TC in the LIF locus gave birth and raised significantly more live piglets in the first litter compared with sows with the CC genotype.