The Impact of Single Nucleotide Polymorphism Ss52050737 in Luteinizing Hormone/Choriogonadotropin Receptor Gene on Some Reproductive Traits in Friesian Cows.

The luteinizing hormone/choriogonadotropin receptor (LHCGR) gene is potentially a useful genetic marker for cattle reproductive status. This study aimed to investigate the impact of the LHCGR gene's ss52050737 polymorphism on age at first calving (AFC), calving interval (CI), and ovarian status using the TaqMan PCR assay. AFC was categorized into 25-34 and 35-45 months, while CI was grouped into 330-410 and 411-800 days. Ovarian status was classified as active or inactive ovaries. Blood samples were collected from cows using EDTA-containing vacutainer tubes and stored at -20°C until DNA extraction and analysis. Three genotypes (GG, GT, and TT) were identified for the LHCGR gene SNP (ss52050737). The homozygous GG genotype was more frequent in cows with a CI of 330-410 days, and the genotype distribution showed a statistically significant association (p = 0.018) in cows with CI 330-410 and 411-800 days. On the other hand, the GG genotype was not significantly different in relation to AFC and ovarian status (active or inactive). These findings suggest that the ss52050737 polymorphism of the LHCGR gene has an impact on calving interval, and the G allele is associated with the CI of 330-410 days.