A pig鈥檚 ideal temperature is 65 degrees Fahrenheit.
So on a 90-degree day in the middle of July, Phil Borgic keeps a close eye on his herd.
鈥淎 pig can鈥檛 sweat,鈥 he says. 鈥淪o the only way that it can transfer the heat is by panting.鈥
The air is humid and heavy with the smell of manure on in Raymond, Illinois. Although the pigs aren鈥檛 panting yet, Borgic, the farm鈥檚 owner, turns on eight massive cooling fans with six-foot blades designed to suck the hot air out of the long barn. If it gets hotter still, he says it鈥檒l be time to turn on the sprinklers.

鈥淧igs can't talk to us, but we can listen to them, and we can do that by ... observing their habits,鈥 Borgic says. Their habits have changed over the years, he says, and he鈥檚 had to react accordingly.
鈥淎s we went through time, our fans kept getting bigger and bigger and bigger to pull more air through and over the top of the pigs and to get that heat out of there,鈥 he says. 鈥淚n the beginning we didn't add water, and so as we learn, we started adding that sprinkle water then to help cool them off some more.鈥
As summers heat up due to climate change, Borgic says he鈥檚 invested thousands of dollars in new systems and technologies designed to protect his animals from the dangers of heat stress. And he鈥檚 not alone.
The effects of heat stress
Not only is keeping animals cool essential for their comfort and safety, but it鈥檚 also important for their productivity.
Borgic says pigs don鈥檛 eat when they鈥檙e too hot, so it takes longer for them to hit their target harvest weight.
The same goes for cows, says Mississippi State University professor , whose research focuses on heat stress in dairy cattle.
鈥淒airy cattle, particularly lactating dairy cattle, experience heat stress at a lot lower temperature than what most people would imagine,鈥 she says.
Signs of heat stress start to show up around 68 degrees Fahrenheit, she says. At that point, there are a range of effects, including reproductive issues and decreased milk production of up to 25%.
鈥淪o if a cow is producing one hundred pounds (of milk), during periods of heat stress, she's only producing 75 pounds,鈥 she says.
More research is needed in this area, Stone says, as global temperatures continue to rise and the number of dangerous heat days increases.
鈥淭he world is getting hotter, and so we are seeing more issues related to heat stress,鈥 she says. 鈥淎s the world changes, agriculture has to adjust with it.鈥
Cool technology
Stone says some adjustments are already happening.
Through her work with the university鈥檚 extension office, she鈥檚 seen farms in Mississippi get creative in order to keep up with the heat. For example, one farm repurposed a center pivot irrigation system, typically used for irrigating crops, to cool down livestock.
鈥淧roducers are, I would say, the most resilient people that you would ever meet,鈥 Stone says. 鈥淭hey're very good at adapting.鈥

On Borgic Farms in central Illinois, technology has played a key role in handling the relentless summer heat. In addition to the computer-controlled fans and sprinkler system, some of the pigs also live in cool cell facilities with honeycomb-like walls made out of treated cardboard. Water drips down through the honeycomb, and fans pull the wet air through the facility, reducing internal temperatures by up to 15 degrees Fahrenheit.It鈥檚 a more effective way to cool off the sows, says Phil Borgic, and it鈥檚 becoming increasingly common due to the hotter temperatures despite the cost of implementation.
鈥淭en years ago, not everybody would have put this in,鈥 he says. 鈥淣ow it's standard equipment.鈥
鈥榃e need protection鈥
Keeping animals cool is arguably more difficult for farmers who raise animals outside -- like Wes Jarrell, who co-owns and operates in Champaign, Illinois. He and his wife keep more than 100 goats and use their milk to make cheese and gelato.

鈥淕oats don't like to stay out on super hot days,鈥 Jarrell says. 鈥淎nd so because we want them to go out and behave like goats outside, we want to make sure that they don't overheat.鈥
Climate change is making that harder, he says. He鈥檚 noticed changes in their milk production over the years.
鈥淲e've always known that in the summer heat, their production goes down. And we know just by looking at the records that the duration of that and the intensity of that is increasing.鈥
The farm is pasture-based, so the goats spend most of their time outside grazing on grass and shrubs. Like dogs, Jarrell says goats pant when they get too hot and take cover in the shade under trees. To protect his goats from heat stress, he is experimenting with , which involves planting trees in livestock pastures.
But climate change-induced droughts and high heat days are making pasture-based systems more difficult to keep up with.

鈥淲e know that the pastures are going to dry up if we get the summer droughts that it looks like we will be getting,鈥 he says.A couple of small barns on the farm also provide shade for the goats. But Jarrell says they鈥檙e making plans to build a bigger indoor facility, in part because it鈥檚 getting harder to keep the goats cool enough.
鈥淚n summer, when it's going to be hotter and more humid, we need the best ventilation possible, and we need protection,鈥 he says.
The cost of keeping cool
The price tag on that new barn -- which will double as a creamery and office space -- is nearly $700,000.
Climate experts that if we continue emitting greenhouse gases at the current rate, most of the summer in Illinois will consist of , or days with a heat index above 110 degrees Fahrenheit.
While that might make the new barn worthwhile, Jarrell says they鈥檒l have to find a way to pay for it, and that may result in higher prices.
He鈥檚 confident his customers will be happy to help.
鈥淚f people are aware of the benefits that we're providing, in addition to a really good tasting product and one whose nutrition we can demonstrate and benefits to human health, we think we'll be able to manage that.鈥
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