An analysis of CYP19, CYP21 and ER genotypes in Polish Holstein-Friesian cows with regard to the selected reproductive traits

Abstract

The aim of this study was to relate polymorphic variants of CYP19 , CYP21 and ER1 genes to reproductive traits in 472 Polish Holstein-Friesian cows. High frequencies of one of the homozygous genotypes were found. The ER1 / Sna BI AA homozygotes were not identified. In the first and third lactation, an average calving-to-conception interval (CLVC) in cows of ER1 / Sna BI GG genotype was significantly shorter ( P ≤ 0.05) than in heterozygous cows. In the cows of ER1 / Bgl I GG genotype, significantly shorter CLVC ( P ≤ 0.05) was observed compared to heterozygotes in the first lactation, whereas in the third lactation, CLVC in homozygous cows was significantly longer ( P ≤ 0.05) than in heterozygous ones. It was also found that homozygous cows were characterized by significantly longer calving interval (CLVI; P ≤ 0.05) compared to heterozygotes in the third lactation. Longer CLVCs in CYP19 AA cows were found, compared to heterozygotes, and this difference was significant in the first and third lactation ( P ≤ 0.05). Similarly, the average CLVIs were longer in CYP19 AA homozygotes than in heterozygous cows; however, significance was proven only in the third lactation ( P ≤ 0.05). Description of the molecular mechanisms regulating reproduction, and thus identification of the individuals of genotypes with optimal potential may facilitate the employment of selected reproductive model by a breeder.