The global temperature is rising, and it is having an impact on the livestock industry.
Heat stress has a huge impact on livestock of all species, says Lance Baumgard, professor of animal science at Iowa State University.
“It has a huge financial impact as well as causing issues with animal welfare,” he says.
For example, heat stress in dairy cows causes a reduction in milk that cuts into a producer’s bottom line. Feed efficiency decreases during periods of heat stress.
Baumgard says heat stress can impact the unborn offspring of sows, both immediately and throughout their lives.
“Pigs don’t sweat and have a thick coat of fat that acts like insulation,” he says. “Heat stress is a major concern for those pigs.”
While most associate heat stress with hot summer days, Baumgard says many heat problems for beef cattle occur in May and June.
“Cattle will acclimate to the environment, so they are more used to it in July and August,” he says. “In early summer, they aren’t used to the heat, and that’s when you see more deaths.”
Cattle that get too cold will burn up energy trying to stay warm, reducing feed efficiency and average daily gain, Baumgard says.
Wind speed and humidity play big roles in heat stress, says Dan Thomson, a veterinarian and chair of the Department of Animal Science at Iowa State. He says the combination of a hot day, high humidity and no wind can be too much for some cattle.
“Cattle accumulate heat, so if it’s hot and sticky, they are going to need night cooling so that heat dissipates from their body,” Thomson says.
Paying attention to the thermal heat index should help with heat stress management. Iowa State’s numbers for all livestock species can be found online at bit.ly/3pncGEn.
Thomson says cattle can often be found in clusters, particularly under shade trees in the pasture. He says while this may offer a slight respite from the heat, it can cause other health problems.
“They are going to stand there and urinate, and that bog can create foot rot,” Thomson says.
Portable shade can be included in a pasture. Thomson says access to clean water is also important.
Extreme weather events in the winter can also be deadly. Thomson recommends producers have some sort of emergency plan in place.
“With the beef industry, most of those animals are outside, and we are going to have to be able to deal with the weather extremes that we have in the Midwest,” he says.
Baumgard says as the climate continues to change, livestock producers need to be prepared.
“We need to figure it out and make sure we are doing everything we can from both a financial and animal welfare perspective,” he says. “These heat waves seem to be getting hotter, and we need to be ready to do what we can.”