Experts from India’s national institute of animal nutrition (ICAR) have said new management and nutrition strategies are needed to protect livestock from heat stress in areas that are feeling the impacts of climate change.

On Thursday, the UN’s World Meteorological Organisation (WMO) released provisional figures to coincide with the COP22 climate talks in Marrakech that show 2016 is on track to break temperature records (and other worrying records associated with runaway climate change). WMO also noted that other UN bodies have estimated that almost 20 million people, from over 100 countries worldwide, were forced to leave their homes as a result of extreme weather or unpredictable conditions associated with climate change in 2015 - this is twice the number of people displaced by war last year.

Looking at heat stress and food sources, ICAR’s Dr Veerasamy Sejian reviewed recent research and concluded that livestock immune functions are either suppressed or enhanced, depending on the length of exposure to heat stress. Heat stressed animals’ immune systems, helping them cope with the immediate threat, but potentially making them more susceptible to diseases. Heatwaves at critical times can also affect the transfer of antibodies to young animals through milk.

For parts of the world where heat stress is becoming rife,Dr Seijan recommended making animal shelters and possibly providing evaporative cooling systems, as well selecting livestock for heat tolerance in breeding programmes.

Modifying livestock nutrition can also prove effective in combating the effects of stress; the ICAR team found that efforts to boost livestock’s immune systems would pay off in a changing climate. Dr Seijan said Vitamin A and zinc supplements can help maintain protective barriers against pathogens in the gut and udders. Combined supplements of selenium and vitamin E can positively influence the ability of white blood cells to attack pathogens. Iron can also play an important role in promoting the development of immune-related glands.

Boosting naturally occurring bacteria present in the guts can also form a protective strategy, according to the Indian team. Prebiotics are indigestible ingredients that stimulate the growth and activity of gut bacteria. When gut bacteria are healthy, they compete against invading bacteria for food, preventing the invaders from flourishing. Probiotics are mixtures of live microorganisms that are beneficial to animal health. These line the gut, strengthening its mechanical barrier. They also compete with harmful bacteria, making it more difficult for them to survive.