Genomic Regions Associated with Fertility Traits in Mexican Holstein Cattle

Genome Wide Association Studies (GWAS) are tools that allow the detection of genes or quantitative traits loci (QTL) related to economically important and functional traits in livestock production. The aim of this study was to identify significant SNP associated with fertility traits (days at first service (D1S) and calving interval (CI)) in Mexican Holstein cattle, and to search if these markers are referenced in the UMD_3.1 database.

Phenotypes were genetic breeding values for D1S and CI. After the quality control analysis, a total of 978 individuals and 15,724 SNP were included. GWAS were performed with a mixed model and regression analysis (GRAMMAR) accounting for the genomic kinship matrix, using the GenABEL package of R. Regions with more than two SNP with a p<0.0001, were assumed significant.

Two regions were related with D1S and were located in chromosomes 3 (Positions 11129475, 11563040 and 11740431) and 25 (Positions 1184038, 1205232, 2691937 and 4157331), but these regions were not previously associated with fertility traits. For CI, also two regions were significant and these were located in chromosomes 3 (Positions 70120751 and 84094824) and 10 (Positions 26852413, 31364551 and 44733798). The significant region in chromosome 3, has been previously related with the fertility index of Danish and Swedish Holstein cattle and the SNP with position 31364551 in chromosome 10, has been located inside a reported QTL which is related to No-return rate in German Holstein cattle.

Work funded by Project INIFAP-SIGI-MEXICO No. 11402733072.