Development of climate resilient dairy cattle: Need of the hour

Climate change poses a major threat to livestock production systems worldwide, and its effects are expected to intensify in the coming decades. Rising temperatures and relative humidity, increasing atmospheric carbon dioxide concentrations, changing precipitation patterns, and more frequent extreme weather events affect dairy production. Dairy cattle are particularly vulnerable to heat stress because milk synthesis generates substantial metabolic heat. Climatic stress can reduce production and reproductive performance, restrict feed and grazing resources, increase disease incidence and mortality, and contribute to the erosion of animal genetic diversity. Physiological measures such as rectal temperature, respiration rate, and heart rate have traditionally been used to assess heat tolerance, but their routine use may be limited by recording costs, labour requirements, technical capacity, and incomplete consideration of environmental factors such as wind speed and solar radiation. Because thermotolerance has a genetic component, genomic selection offers a potential route to developing climate-resilient dairy populations. Important challenges include limited phenotypic and genomic data, antagonistic genetic relationships between heat tolerance and milk yield, and resource constraints in developing countries. This paper outlines a genomic-selection framework integrating phenotypic screening, climate-resilience indicator traits derived from milk-yield perturbations, genome-wide association studies, and genomic estimated breeding value estimation using PBLUP, GBLUP, ssGBLUP, and Bayesian methods. The framework concludes with validation of selected animals under controlled climatic-chamber conditions. This integrated approach may help identify and breed indigenous dairy cattle with improved climatic resilience and support sustainable dairy production under a changing climate.