Polymorphism of PIT-1 Genes and its Relationship with Traits in the Limousine Cattle Breed

The aim of the study was to analyse the polymorphism of the PIT-1 gene withe introns 4 and 5 and exon 6 in the Limousine cattle breed and its relation to selected rearing traits. Relationships were determined between the genetic variants of the three polymorphic sites of the PIT-1 gene and the following rearing parameters: body weight at birth, body weight at weaning on day 270, daily weight gain from birth to weaning, age at first calving and body weight after first calving. The frequency of alleles of the analysed loci was: T =0.2887 and G =0.7913 (IVS4-39G>T), A =0.1087 and G =0.8913 (IVS5+438G>A) and A = 0.2913 and G =0.7087 (c.1178G>A). For each of the studied polymorphic sites, homozygotes (-,-) were found least frequently. The results showed relationship between polymorphism in loci IVS5+438G> A and c.1178G>A, and rearing traits. The analysis confirmed significant statistical differences (P ≤ 0.05) between homozygotes (+,+) and heterozygotes (+,-) for the following traits: age at first calving (IVS5+438G>A), weights at weaning (c.1178G> A) and daily weight gain from birth to weaning (c.1178G>A). The most preferable results were found for homozygous (+,+) animals. The mutation in 6 exons 6 proved particularly interesting (c.1178G>A), and the GG genotype was the most advantageous genetic variant.