Acta Vet. Brno 2011, 80: 65-71
An analysis of CYP19, CYP21 and ER genotypes in Polish Holstein-Friesian cows with regard to the selected reproductive traits
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/SnaBIAA homozygotes were not identified. In the first and third lactation, an average calving-to-conception interval (CLVC) in cows of ER1/SnaBIGG genotype was significantly shorter (P ≤ 0.05) than in heterozygous cows. In the cows of ER1/BglIGG 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 CYP19AA 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 CYP19AA 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.
Keywords
Gene polymorphism, calving interval, calving-to-conception interval, pregnancy length, inseminations.