Climate change is coming for the dairy industry

Higher average temperatures and more frequent heat waves are likely to occur due to climate change. This week, it is estimated that about 20% of people in the United States are experiencing temperatures above 100 degrees Fahrenheit. Meanwhile, recent heat waves in India and Pakistan have claimed at least 90 lives and reduced agricultural yields by 10-35% in some areas.

Due to rising global temperatures, heat stress in livestock, which results from combinations of air temperature, humidity, solar radiation and wind speed, could increase. This added stress makes it difficult for animals like cows and pigs to control their own body temperature. If livestock are unable to dissipate heat effectively, their body temperature will rise, which can reduce their productivity, thereby affecting food supply.

Of the major livestock industries in the United States, the dairy industry is considered the most vulnerable to economic losses from heat stress, says Amanda Stone, assistant professor and dairy extension specialist at Mississippi State University. The risk of the dairy sector is considerably higher than that of beef cattle, the second most vulnerable industry. To keep the $827 billion global dairy industry going as the planet warms, it is crucial to understand the extent of the impact of climate change on beef production and to mitigate its effects.

Rising global temperatures will affect beef production

Heat stress not only affects the behavior and welfare of cattle, but also reduces their feed intake, productivity and fertility, says Philip Thornton, senior scientist at the International Livestock Research Institute and leader of the CGIAR research program on Climate Change, Agriculture and Food Security.

“Animals eat less and increase their respiration, so more energy is spent trying to stay cool, with less energy available for meat and milk production,” he added. In addition, it increases their susceptibility to disease and, under extreme heat stress, their mortality as well. Just recently, extreme heat killed thousands of cattle in Kansas, one of the nation’s largest cattle producers.

According to a study published in The Planetary Health of the Lancet in March, the impact of climate change-related heat stress on dairy and beef production could result in global meat and milk production losses amounting to around $40 billion per year by the end of the century for a high greenhouse gas (GHG) emission scenario. Even in the best-case scenario of low emissions, producers could be looking at a loss of around $15 million.

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To calculate these losses, the authors predicted changes in the animal’s feed consumption in response to hot, humid weather under various GHG emission scenarios. They converted these changes in food intake into changes in milk and meat production and then valued them using 2005 prices, says Thornton, who is one of the study’s authors.

Based on the study, losses in tropical regions are estimated to be higher than those in temperate regions, for both high and low emission scenarios. “Parts of the northern temperate regions of the globe could see increased production as cold spells abate,” says Thornton. “In other words, more of the energy in the food animals eat can be spent on producing meat and milk, rather than keeping the animal warm.”

The impacts of heat stress on cattle can affect the food safety and diet diversity of producers and consumers. Producers may experience reduced income, loss of assets and reduced resilience of their livelihoods, while consumers may face higher prices for meat and milk, Thornton says.

The food supply depends on produce from farms, so any time there is a disruption in these systems, the entire food supply chain suffers, Stone says. “We could see a change in the position of these farms in relation to our consumers – for example, ‘local’ can be a farm 100 miles away instead of 10 – and there will be fewer farms with more cows responding to all our needs,” she said. adds. Therefore, it is crucial to mitigate the impacts of increased heat stress on beef production.

Farmers can adopt various adaptation interventions

However, there are many coping methods that farmers can try to keep their cows cool even in record heat.

Cows cannot sweat like humans, so in confinement operations where cows live inside a barn, fans and sprinklers can be used to create an evaporative cooling system, Stone explains. There are also sensor technologies that monitor cow behavior as well as physiological and production changes, which can adjust barn temperatures based on what is happening with the cows, she adds.

For outdoor production systems, a wide range of feed additives such as betaine or chromium can mitigate heat stress to some extent due to their antioxidant capacity. Livestock grazing systems coupled with trees can also be effective in shading animals during hot, humid periods, says Thornton. In parts of Africa, some farmers are switching species altogether: from cattle to more heat-tolerant goats or even camels, he adds.

“Longer term, there are prospects for breeding animals with greater tolerance to heat stress, perhaps also through cross-breeding programs,” says Thornton. “Such approaches can, however, be quite expensive and take several years to materialize.”

Policy makers will need to support the beef industry

To keep dairy farmers in business with rising production costs and declining production due to increased heat load, producers need to receive more money per unit of milk produced, Stone says.

“Policies that control milk market volatility are of utmost importance to dairy farmers,” she adds. “We continue to improve our efficiency to produce more milk with [fewer] cows, land and resources, but there have been few rewards for these improvements in the bottom line for producers. The lingering expectation that farmers can continue to do more and more with less and less has to have a breaking point and I think we may be reaching it.

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As the world continues to warm, heat stress is becoming an increasingly difficult problem for both livestock and humans working outdoors. Some places will be too hot for animals to thrive, especially in low-income countries. Shifting animal production to more conducive environments within countries may be an option, although this is highly dependent on country markets, economics, and social and cultural considerations, says Thornton.

However, all measures to combat the effects of heat stress must be accompanied by a significant reduction in emissions in order to mitigate climate change and to continue global warming. “In the long term,” says Thornton, “the most effective way to meet the challenge is to redouble our collective efforts to reduce greenhouse gas emissions as quickly and as completely as possible.”