Dairy cattle

Genomic regions associated with reproductive traits and uterine health in dairy cows under smallholder production systems in Mexico.

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Abstract

Reproductive efficiency is a key determinant of profitability in cattle production systems due to its impact on productivity, longevity, and calving intervals. This efficiency is influenced by the interaction of environmental, management and genetic factors, particularly genes regulating fertility, uterine function, and postpartum health. The aim of this study was to find genomic variants associated with two reproductive traits and one uterine health indicator in dairy cows under smallholder systems, contributing to a better understanding of the molecular basis of reproductive efficiency.A total of 60 dairy cows were genotyped using the Axiom Bovine 100K Array®. Phenotypic variables included the natural logarithm of days open (DO), number of services per conception (NSC) and percentage of polymorphonuclear cells as an indicator of subclinical endometritis (SE). The statistical model included the fixed effect of year-herd-season and the random additive genetic effect. Quality controls were applied in PLINK v1.9, including SNPs and genotypes with a call rate > 0.95, MAF > 0.05 and Hardy-Weinberg equilibrium (p > 1e-4), keeping 77589 SNPs. QTL and gene searches were performed in Rstudio v4.5.1 using the Gallo package with ± 10 kb windows around significant SNPs.Using an exploratory threshold of P MRPL3 (chromosome 1), DKK2 (chromosome 6) and HERC1 (chromosome 10); TYW5 (chromosome 2) for NSC; and TBC1D5 (chromosome 1) for SE. SNPs associated with DO overlapped regions previously linked to calving ease, calf size, inhibin level, Interval from first to last insemination, milk components and tick resistance. For NSC, found regions corresponded to QTLs for weaning weight and milk lipid profile, while SE shared regions with QTLs for maintenance efficiency and muscle fatty acid composition.We also found SNPs in regions with no earlier QTL reports, for DO on chromosomes 9, 14, 24 and 29; and for NSC and SE on chromosome 24. These regions stand for potential new genomic regions associated with fertility and uterine function, calling for further functional validation.These results highlight multifunctional genomic regions of biological interest that link reproduction with health and production, providing a foundation for genomic selection strategies aimed at improving reproductive efficiency in dairy cows.

Keywords: 2026

How to Cite:

Vidals-Meza, M., Vera-Ávila, H., Ruiz-López, F., García-Ruiz, A., Villaseñor-González, F. & Durán-Aguilar, M., (2026) “Genomic regions associated with reproductive traits and uterine health in dairy cows under smallholder production systems in Mexico.”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2287202. doi: https://doi.org/10.31274/wcgalp.24611

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