Climate Change Is Draining India's Milk Bowl: How Heat Stress Is Hitting Haryana's Buffaloes Hard

Researchers from the ICAR-National Dairy Research Institute and collaborating institutions studied bovine milk production across 1,148 villages in Haryana from 2004 to 2019, covering a livestock population that included 4.66 million cross-bred cattle, 2.86 million indigenous cattle, and 35.56 million buffaloes. The study, published in Scientific Reports, assessed the influence of minimum, maximum, and mean temperatures, heavy rainfall, temperature-humidity index, and evapotranspiration on yields across all three bovine categories.

The verdict is unambiguous: temperatures exceeding 38°C in combination with humidity above 70% — conditions that peak in July and August — significantly suppress milk production. Notably, winter temperatures had a negligible effect, underlining that it is the summer-monsoon overlap that poses the greatest threat to the high milk production tract of Haryana.

Buffaloes are disproportionately vulnerable due to their darker pigmentation, exposed skin, and notably fewer sweat glands compared to cattle. The study quantified this precisely: a unit increase in potential evapotranspiration (mm/day) reduces milk yield by approximately 1.4 litres per buffalo per day.

The mechanism is well understood. Rising temperature-humidity index triggers homeostatic responses — panting, sweating, and reduced activity. Animals divert energy away from milk production toward thermoregulation. Elevated cortisol and stress hormones impair milk ejection, and in severe cases, the paper warns of livestock mortality.

Cross-bred cattle also showed significant productivity declines during heatwaves. Indigenous breeds like Sahiwal and Hariana, however, demonstrated resilience — attributed to loose skin, efficient sweating, lower metabolic heat output, and stronger immunity against local parasites and pathogens, which matters because heat stress routinely compromises immune function.

The climate threat does not stop at the animal. Rising surface temperatures are disrupting the quantity, quality, and seasonal availability of feed and fodder — a cascading effect that further weakens livestock productivity even before heat stress sets in directly.

Abhinav Gaurav, lead advisor for sustainable dairy at Environmental Defense Fund India, told The Hindu that lactating animals are especially vulnerable during intense summer months, with energy being diverted from milk synthesis to body temperature regulation. He noted a 20–30% decline in milk yield during peak heat stress periods. Beyond the farm, increasing water scarcity, more frequent pest and disease outbreaks, and a compromised animal immune system are collectively straining the broader dairy production system — risks that fall hardest on the 80 million smallholder dairy farmers who contribute 85% of India's total milk output.

The study offers a note of cautious optimism: Haryana's farmers were found to be already aware of adaptive measures and implementing them during summer months. These include wallowing ponds for buffaloes, agroforestry, livestock sheds, sprinklers, foggers, mist systems, and adjusted feeding management — interventions that meaningfully blunted the worst seasonal impacts.

At the research and policy level, the authors recommend integrating potential evapotranspiration and temperature-humidity index into regional early warning systems for proactive herd management. For the longer term, the paper calls for breeding programmes that leverage Bos indicus traits — with the Sahiwal breed specifically identified as significantly more heat-tolerant than exotic breeds at comparable productivity levels. The National Bureau of Animal Genetic Resources has already identified heat-tolerance markers including heat shock proteins, coat colour, and hair characteristics.

Indigenous breeds should be conserved as 'reservoirs of climate-resilient traits', the study concludes, with policies backing in-situ conservation and farmer-led breed improvement.

Despite the on-ground ingenuity of Haryana's farmers, Dr. Gaurav identified a critical structural gap. "The larger challenge now lies in scaling these solutions for millions of smallholder farmers, who often face limited awareness, inadequate financial resources, and the absence of a coordinated national climate-smart dairy strategy," he said.

Citing a Lancet report, Dr. Gaurav flagged a potential 25% reduction in Indian milk production by 2085 due to climate-induced temperature rise — a figure that would place the livelihoods and nutritional security of millions at risk, given that India remains the world's largest milk producer and consumer. With losses already at ₹2,661 crore annually and a trajectory pointing toward 15 million tonnes of lost production by the 2050s, the window for a coordinated national response is narrowing.