kailas Ramasamy carefully leads his cows to a hangar-sized barn, ties them to their stakes, puts down their feed and clears the floor. Then, when he steps outside, he flips a switch: ceiling fans start blowing air on the cattle.
Ramasamy’s dairy farm is located an hour outside the city of Bengaluru in southern India. The region is usually known for its temperate weather and has witnessed a sharp rise in temperature compared to previous decades. Elsewhere in India, temperatures have reached 50C (122F) this year.
That’s bad news for the Indian dairy industry, with heat stress leading to decreased appetite, less weight gain and reduced fertility in cattle. Rising temperatures could reduce milk production in India’s warmer regions by 25% by 2085, according to recent research published in the Lancet.
Heat stress is a global problem, with thousands of cattle dying last week in the US state of Kansas as temperatures over 37C were exacerbated by high humidity.
But for India, a significant drop in milk production could be devastating to food security if it ends dairy self-sufficiency in the world’s second most populous country.
The consequences would also be devastating for 80 million Indians who work in the dairy industry.
These are issues Ranganatha Reddy knows well. Temperatures at his dairy farm in Anantapur, 120 miles (200 km) from Bengaluru, reached 43C in May.
“My cows usually have an internal alarm clock and start howling at mealtime because they are always hungry,” he says. “But during the heat wave, I almost had to force-feed them.”
His farm’s milk production fell by 30% month-on-month. “It felt like I was wringing out a dry sponge.”
Although climate change is a global phenomenon, India’s large number of small dairy farms and a growing reliance on breeds vulnerable to heat stress could affect the country more than other major dairy producers such as the US or Brazil.
In the 1970s, India began crossing high-yielding imported cattle breeds with local varieties, turning the country from a dairy shortage to producing 22% of the world’s milk.
The most recent cattle census in India showed that the population of crossbred cattle had increased by 26% since 2012, while the native varieties decreased by 6%.
It makes financial sense to switch to crossbred cows because they produce “a lot more milk,” says Ramendra Das, a veterinary scientist who has studied the impact of warming temperatures on different breeds — but they are more vulnerable to heat stress than native breeds.
Ramasamy, who buys and sells milk from local farmers through the company Vrindavan Dairy, is trying to promote the use of native cows by paying more for milk from Indian cows (42p per litre) than crossbred (32p).
Solutions to combat heat stress include specially designed barns with fans and sprinklers to keep livestock cool, but that comes at a high cost. “Only large, intensive dairy farms can afford such an infrastructure,” said Girdhari Ramdas Patil, former co-director of the National Dairy Research Institute. Nearly two-thirds of India’s milk is produced by small-scale farmers.
Philip Thornton, a scientist with the Consortium of International Agricultural Research Centers and lead author of the Lancet study on milk yield losses due to heat stress, says crossing climate-resistant breeds of cattle and higher yielding cows could help in the long run.
For Ramasamy, the answer was to look for better native breeds. He started breeding Gyr cows from Northern India that give more milk than other breeds while also consuming less food and water than crossbred breeds.
Does he think the lower maintenance costs and the risks of heat stress will convince more farmers to switch to Indian varieties? “It will be difficult, but I am convinced that this is the future,” he says.
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