American scientists are attempting to breed chickens that can cope with scorching heat as part of a series of government-funded programmes to mitigate the effects of extreme weather patterns on the food supply.

A University of Delaware project is trying to introduce climate hardiness to the US domestic breed stock before summer heatwaves predicted under climate change models kill or spoil the meat of billions of birds.

Lead scientist Professor Carl Schmidt's concern isn't over slight increases in average temperatures, but the rising frequency and duration of crippling heatwaves and other extreme events.

This month, President Barack Obama, seeking to make stricter carbon emissions regulations a centrepiece of his second term, described climate change as "a problem affecting Americans right now".


By 2060, US climate agencies predict, there will be 12 times as many 38C days in Delaware and Maryland, where poultry farmers produce 600 million birds a year.

"Hotter periods will last longer, and that's when we'll see significant spikes in mortality and other stress factors coming in," Schmidt warns. "We can't wait for that to happen. We have to prepare now."

As climate change causes continue to be disputed, the US Department of Food and Agriculture is funding more research on limiting climate-related disruptions to the food supply.

"There's a one-government approach to this issue," said Sonny Ramaswamy, director of the USDA's National Institute of Food and Agriculture. "For us, it comes down to adaptation and mitigation. There's a concerted and co-ordinated push for food security to be achieved, and it's being pushed hard."

Grants have been given to research on how cattle can adapt to drought, on the effect on pollinators such as bees, and on toxin-producing fungi in wine-making.

The shift in policy emphasis was highlighted this month with the publication of an exhaustive National Climate Assessment that identified areas of agricultural production experiencing "climate-related changes that are outside recent experience".

For researchers, the challenge with poultry lies in mapping the genomes of different species. In extreme heat, chickens, like dogs, will pant. That changes the chemical balance of their blood, introducing a bitterness to the flavour of the meat.

The complexities of bird reproduction present difficulties to genome engineers. It's not possible simply to cross a heat-resistant chicken such as the African naked-neck with a domestic bird without losing qualities you'd want to keep, explains Schmidt.

Research into turkeys and cattle has found Western palates won't accept meat from heat-resistant cattle such as the Indian brahman.

Many environmentalists prefer to see the emphasis placed on prevention rather than adaptation. But prevention alone is no longer realistic, Schmidt says.

"We need a rational approach to provide food in the context of a changing climate as the population approaches nine billion. The expectation is people will eat more, specifically more poultry because that's the cheapest way to meet demand for more meat. The combination of climate change and increased demand is a recipe for enormous problems."

Ramaswamy says farmers may not agree over climate change, but they can see changes as the industry deals with extreme weather. "We must ask [how we can] develop better crops and animal species because this is the situation we've got."

Gates backs substitutes
Microsoft's co-founder, Bill Gates, is backing technology that uses pea protein to create substitutes for beef and poultry.

"There's no way to produce enough meat for nine billion people," Gates wrote on his blog.

"Yet we can't ask everyone to become vegetarians. We need more options for producing meat without depleting our resources."

- Observer