nature & planetanalysisThe Conversation (Australia)

Overheating cattle: more and more dangerous heat is coming for northern Australia’s herds

the gist

Cattle are built to produce heat, not lose it: fermenting grass in their stomachs generates constant warmth, and they sweat poorly, so they rely on panting, shade and cool nights. About half of Australia's 30.8 million cattle graze the hot tropical and semi-arid north. Researchers using climate models compared 1990–2010 with the 2050s and 2090s and found that dangerous heat levels will arrive more often, adding months of heat stress. British breeds (Bos taurus), poor at shedding heat, will suffer most; tropical Brahman-type cattle (Bos indicus) are more resilient but not immune. Shade structures could shield cattle from much of the extra heat, and mustering at dawn avoids the hottest hours.

so what

Australians eat about 22 kilos of beef a year, and beef is a major export, so heat stress affects both animal welfare and farm incomes. Simple adaptations such as shade are cheap compared with the losses.

fun fact

Brahman cattle descend from zebu cattle of the Indian subcontinent.

The Conversation

Illustrative photo · Kim Hansen, CC BY-SA 3.0, via Wikimedia Commons