As Milk Production Cools In Summer, Farmers Try To Help Cows Take The Heat

"Any dairy farmer — commercial, small, local — are experts in dealing with heat," says Miller. That is because the way cows digest food takes a lot of energy and generates a lot of heat. When it gets too warm outside, cows want to cool down. So they spend that energy panting, and as more blood flows to their skin, they sweat. They lose their appetite. As Miller puts it: "They just stop eating. It's harder to get feed into them." Without food, cows stop producing as much milk. The cows at Mill-King give about 33 percent less in the hot summer months. That means less money for this family business. "There are a lot of cows that will be living in hotter climates," says Geoffrey Dahl, chair of the Department of Animal Sciences at the University of Florida, Gainesville. Dahl says the problem is bigger than just hotter summers. His research shows how pregnant cows that suffer heat stress give birth to calves that also produce less milk. The phenomenon is similar to what people who study epigenetics see in humans. "In utero, negative effects can lead to higher incidents of diseases later in life," says Dahl. "It's kind of a negative cascade that occurs." He and his colleague are working on one solution. They have bred a new kind of dairy cow. It includes the DNA of a South American cow breed that has adapted to better withstand heat. At the Southwest Regional Dairy Center in Stephenville, Texas, Barbara Jones is looking at more traditional ways of helping cows cope with the heat. "We have fans here and we also have sprinklers," she says, walking through one of the barns, where cows munch on feed while water mists them from overhead. "It should wet the cow to her skin," says Jones, "then those sprinklers will shut off. The fans will keep going, and we're going to employ that evaporative cooling to cool the cows." The dairy center is on the campus of Tarleton State University, and Jones is researching how different cooling techniques affect milk production. She says these water and fan setups are pretty common in the South and Southwest, but they could be used more...MORE