Environment & Energy
Related: About this forumRanchers In SW Forced To Look To Heat-Resistant Breeds, Along With Misters, Canopies As Heat Digs in
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Many of the regions pigs and poultry are raised indoors, where farmers combine methods such as fans, showers, misters and cooling systems. But these cost energy and money, and penning animals indoors can erode their wellbeing, so many farmers also take pains to pasture animals. Jordan raises Cornish Crosses, a breed that grows so fast it outpaces its ability to feather, meaning it develops bald spots. Being so clunky, they are vulnerable to the elements, so Jordan uses evaporative and fan cooling, and shelters birds in shady pens. If we dont do that with meat chickens, then we start going in by the end of the day and picking up dead bodies, he says.
At a higher elevation of 6,000 ft (1,800 metres) in Lamoille, Nevada, Sue Kennedy keeps Freedom Rangers, a less prolific but hardier chicken than the Cornish Cross. If she raised Cornish Crosses, with her combination of heat stress and altitude, she says she would have 50% or more mortality. Even her Freedom Rangers require cooling. So Kennedy sets sprinklers upwind, and constructs poultry houses amid pastures where misty breezes blow through. Despite her efforts, her chickens have been growing slower in hotter, drier recent years. She this might be due to heat stress. When an animal becomes hot, just like when you become hot, you dont want to eat very much, says Tami Brown-Brandl, an agricultural engineer at the University of NebraskaLincoln.
In response to increased internal temperatures, animals eat less, drink more, have lower fertility rates and experience higher mortality rates. When heat-stressed, poultry drink two to four times the water they normally do. Pigs, meanwhile, cannot sweat and begin to feel heat stress at about 21C (70F) Phoenix averaged 37.2C (99.1F) in August 2020 meaning the pigs eat less and their feed spoils more quickly.
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Gregg Vinson, who ranches cattle in the Sonoran and Chihuahuan deserts, has developed a similarly heat-tolerant herd in part by incorporating cattle with select arid-adapted bloodlines. Both herds have adapted to desert sun over time and can flourish with minimal active management. Right now, with record temperatures, our cattle are great, Vinson said in August. Vinsons neighbor raises Angus the most popular cattle breed in the US. In the south-west, Angus cattle need extra care and extra water. If I bought one of your bulls, howd he do? Vinson once asked his neighbor, probing how Angus might fare under hands-off ranching. His neighbor answered: Hed probably die.
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https://www.theguardian.com/environment/2020/nov/02/in-the-sun-theyd-cook-farm-animals-at-risk-as-us-south-west-heats