Genetic Markers Associated with Milk Production and Thermotolerance in Holstein Dairy Cows Managed in a Heat-Stressed Environment

325

Source: National Library of Medicine

Ricardo Zamorano-Algandar, Methodology, Software, Validation, Formal analysis, Investigation, Data curation, Visualization,1 Juan F. Medrano,2 Milton G. Thomas,3 R. Mark Enns,4 Scott E. Speidel,4 Miguel A. Sánchez-Castro,4Guillermo Luna-Nevárez, Software, Formal analysis,5 José C. Leyva-Corona,5 and Pablo Luna-Nevárez, Conceptualization, Formal analysis, Investigation, Resources, Writing – original draft, Visualization, Supervision, Project administration, Funding acquisition5,*
Mingxing Chu, Academic Editor, Ran Di, Academic Editor, and Yufang Liu, Academic Editor
1Departamento de Agricultura y Ganadería, Universidad de Sonora, Hermosillo 83000, Mexico
2Department of Animal Science, University of California, Davis, CA 95616, USA
3Texas A&M AgriLife Research, Beeville, TX 78102, USA
4Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA
5Departamento de Ciencias Agronómicas y Veterinarias, Instituto Tecnológico de Sonora, Ciudad Obregón 85000, Mexico
*Correspondence: xm.ude.nosti@anulp; Tel.: +52-644-4109000

Simple Summary

Holstein is the most popular dairy cattle breed worldwide due to its milk yield. When these cows are exposed to heat stress, they reduce feed intake and milk production in order to minimize body heat production. The large variability associated with this response appears to be genetically regulated. Therefore, we combined genomic and marker-assisted technologies with the objective to validate genetic markers associated with milk production and thermotolerance. A genome-wide association study detected six candidate single nucleotide polymorphisms (SNPs) as predictors for milk production in heat-stressed Holstein cows. Only three of these SNPs were further validated as markers for milk production and thermotolerance traits (i.e., rectal temperature and respiratory rate) in two independent Holstein cow populations. Such markers belong to genes that regulate metabolic functions needed to accomplish energy demands and minimal heat production. The results of this study revealed that heat-stressed Holstein cows with favorable markers were able to reduce rectal temperature and respiratory rate, which allowed them to maintain adequate milk production levels. In conclusion, we validated three genetic markers in heat-stressed Holstein dairy cows, which are useful to be included in selection programs to improve milk yield and tolerance to heat stress.

Please click to here to read full article.