Effect of and gene polymorphisms on fertility traits and milk yield of cross-bred dairy cows in Sri Lanka.

Single nucleotide polymorphism (SNP) analysis of fertility genes will be useful in improving the genetic potential of dairy cows. A population of 142 cross-bred dairy cows was screened for SNPs in bovine luteinizing hormone choriogonadotropin receptor and bovine follicle stimulating hormone receptor genes. The effect of reported SNPs on selected fertility traits (average calving interval, average number of services per conception and age at first calving) and milk yield was determined. Altogether six SNPs were detected in animals screened under the present study. Among them, four SNPs (rs41256848, rs41256850, rs465790244, and rs45463781) were located in the exon 11 region of the gene and two SNPs (rs43676359 and G-278-A (GU253337) were located in the five upstream region of the gene. Minor alleles identified for SNPs in the gene in the studied small population of cows differed from those reported in other research. In this study, only rs45463781 SNP at exon 11 of the gene significantly affected the average milk yield in cross-bred cows. The nucleotide change from "G" to "A" negatively affected the average milk yield. Further investigations are needed to confirm the reported association with a larger sample size.