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Food Res. Int. doi:10.1016/j.foodres.2009.05.018 (2009)

The quality of meat — from pork chop to rump steak — will deteriorate as the world warms, says animal physiologist Neville Gregory of the Royal Veterinary College in London. Gregory's conclusion, based on a review of experimental and field observations of animals, adds to the evidence that climate change will adversely affect the human diet.

Gregory found that extreme summer temperatures could increase the mortality of pigs, poultry, sheep and cattle, particularly during transport to the slaughter-house. As well as early mortality, animals will be more likely to suffer the direct effects of heat stress on organ and muscle metabolism, such as dehydration and lactic acid build-up. These effects can persist after death, leading to paler, moister pork and tougher, darker steak. Carcasses could also become more susceptible to contamination by E. coli and salmonella in a warmer world, says Gregory.

The solution will involve a shift in management practices — cooling animals before slaughter, for example, or switching to more heat-tolerant breeds, such as Bos indicus cattle. But some of these strategies might affect other aspects of meat quality, such as taste, warns the author, who says that experience will be vital in gauging the most appropriate strategies.