KARNAL, INDIA (NYTIMES) - Inside a shed in the northern Indian state of Haryana, the sound of flutes floated softly from loudspeakers. The audience, grazing silently, was dozens of cows, the unwitting subjects of an experiment in music therapy.
The orchestrators of this scene were a group of scientists studying a simple question: How much does withering heat affect milk production? For India's dairy-loving population, another season of rising temperatures has left an answer at their doorstep, as prices have increased for their morning milk deliveries once again.
The scientists of the National Dairy Research Institute are quietly working to preserve India's status as a dairy powerhouse in the face of the country's acute threat from climate change, conducting studies on everything from developing new breeds of buffalo to testing new crops of shrubs for protein content.
As part of this work, a team pored over daily data on yields from hundreds of animals after late-spring temperatures rose as much as 5 deg C above the average of previous years. While the warmer months normally see a drop in yield, the researchers found that heat stress in April had directly resulted in an additional decline of nearly 11 per cent in milk production among healthy crossbred cattle.
"The animal is fighting physiologically to adjust itself, and also give 2 or 3 litres of milk," said Ashutosh, the team's leader, who goes by one name.
India, the world's largest producer of milk, generates more than 200 million tonnes every year. The dairy industry, which relies on 80 million farmers across the country, most with small herds, has grown steadily and now accounts for nearly 5 per cent of India's economy.
In a sign of the country's craving for dairy products - from slow-cooked chai to curd and cheese to the butter and cream that go into seemingly every dish - only a small fraction of the massive production goes to exports.
Stress on animals is just one way that extreme heat is challenging this crucial industry. In announcing a 4 per cent rise in milk prices last week - the second increase this year - dairy producers cited a nearly 20 per cent jump in the cost of feed for cattle.
While rising prices for fuel and other necessities have not helped, scientists and farmers point to how extreme weather is exacerbating an already troubling fodder deficit that is holding India's dairy industry back from further growth.
The wilting heat came earlier this year than usual, with temperatures frequently reaching 45 deg C in April and soaring as high as 49 deg C in May. And it stayed hot for long stretches.
Rainfall, on the other hand, was erratic. The fields were flooded in earlier months when farmers expected less rain, while during the period that precipitation would help mitigate the heat, rainfall was below the norm. In the state of Punjab, farmers reported as much as a 15 per cent drop in the wheat harvest, which affected the availability and quality of cattle fodder.
"Production of wheat came down, so the price of cattle fodder, particularly wheat straw, went up," said Mr Sudhir Kumar Tyagi, who procures milk from farmers in the state of Uttar Pradesh and supplies it to parts of the area around New Delhi, the capital.
"From March to September, the milk production normally remains low, and it picks up again after that," he said. "But this year, because of intense and prolonged heat, the decline in summertime production of milk was 10 to 15 per cent more."
As extreme climate patterns squeeze every aspect of life, India has a major advantage in its robust tradition of scientific research. In institutes across the country, researchers have been seeking answers to questions long before they become topics of public alarm.
India has about 300 million bovines. Nearly half of the milk production comes from buffaloes, and a little over a quarter from crossbred cattle, which combine the resilience of indigenous cattle with the higher yields of European breeds.
In recent decades, as the country has increased the share of crossbreeds because of the better yields, scientists have been closely studying their adaptability to rising temperatures.
The crossbreeds have been slower to adapt than buffaloes and indigenous cattle. The impact of the April heat was minor in buffaloes, a sharp contrast with the roughly 11 per cent drop in production in the crossbreeds, the scientists at the National Dairy Research Institute found.
On a recent visit to the institute in Karnal, which sits on 1,400 acres and includes more than 2,000 animals, a large number of buffaloes grazed on fresh feed.
"When you give them sufficient food, they will not fight," said Dr AK Dang, a scientist at the institute. "Otherwise, like humans, they are bossy - they will fight for it."
In a small corner where work on the impact of climate change is focused, there are special chambers for testing animal behaviour in cranked-up temperatures.
New shrubs from the north-eastern state of Assam, believed to be higher in protein, longer-lasting and shorter in harvest cycles, are going through tests. And researchers are running field trials on the mineral intake of cattle. They have developed a prototype of a tool that gauges temperature and humidity and produces colour-coded readings that help farmers tell animals' stress levels.
Then there were the dozens of cattle munching away as soft flute music played - an image resonant for Hindus, as the deity Krishna is often depicted with a flute and cows in tow.
The music experiment is part of an effort to test all the ways that animal stress can be reduced. About a year and a half ago, when Dr Ashutosh first started the study - "40 to 60 decimal of sounds is the best," he said - the cattle from sheds farther away began congregating near the shed with the speaker.
"We added another speaker there," said Dr Ashutosh, who adapted the study from scientists elsewhere. "We have to find the ways to make the animal stress free. Only then we can make them resilient."
He said it was clear that the shocks from climate extremes contributed to a significant drop in milk production in "normal scientific conditions". But what that means to milk production in the real world depends on the kind of stress-reducing care that is given.
While major dairy farms are able to mitigate the heat with things like fans and water sprinklers, a majority of India's dairy supply comes from small farmers who feed into tens of thousands of village cooperative societies. The tiered effort has revolutionised India's dairy industry over the past 50 years, but it also makes the dissemination of new technology and best practices for efficiency a slower process.
Dr Ashutosh said that while many farmers went to extremes to protect their cattle, which are often their only source of income, shortages of water had made that increasingly difficult. He lamented the decline of old heat mitigation mechanisms such as the shared village ponds that helped buffaloes and cattle cool off.
"Those old systems were having an emergency utility," he said. "But now those facilities are absent."
Mr Bijender Singh, a farmer in the village of Mukari in Uttar Pradesh, has three buffaloes and one cow. He said that about 15 years ago, villagers would take their cattle to the edge of a nearby river during high temperatures.
"Now that river is so polluted that the cattle can't go there," he said. "The other village water bodies have also vanished." This summer, he said, he tried to cool his cattle by keeping them in a covered courtyard where he uses a fan, and by bathing them twice a day.
"The heat and temperature directly affect the milk production," he said, "so we do whatever we can to provide some relief to our cattle".