As the dairy industry faces the challenges of rising temperatures, a new wave of research is bringing hope to farmers and improving the welfare of dairy calves. Grace Larsen, UW-Madison Graduate Student has been helping to conduct this research. She says their research explores both pre- and post-birth heat stress.
The team’s studies have uncovered several challenges that pre-weaned dairy calves face during high temperatures. These include decreased milk intake and increased thermoregulatory behavior. “With the decrease in intake, calves are more at risk to develop diseases and experience stunted growth due to insufficient nutrients,” explained Larsen. “We’ve also identified what we call the ‘hidden impacts’ of heat stress. These affect the calves internally and lead to reduced milk production in their first lactation.”
To combat these issues, the lab has been exploring various heat abatement strategies. One promising solution involves the use of solar-powered fans attached to the back of calf hutches. “This could be a game-changer for farmers who use hutch systems,” Larsen noted. Additionally, traditional methods such as fans and soakers in pen settings have proven effective.
Design considerations for housing also play a crucial role. “Unlike us, calves can’t escape to an air-conditioned room. Simple adjustments, like orienting hutches to catch the dominant breeze, can help provide some relief and improve their comfort,” she added.
The concept of fetal programming is another critical aspect of their research. “The environment of the fetus impacts its development. If a dry cow is heat-stressed, her calf—and even their future calves—are also affected,” Larsen explained. “We’ve found that calves subjected to in utero heat stress have fewer sweat glands, longer hair, and impacted mammary growth, which can lead to reduced milk production.”
One of the most eye-opening discoveries has been the improvement in air quality with the use of fan systems. “We found that the fan group had significantly fewer Colony Forming Units (CFUs) of harmful bacteria, which can make calves less susceptible to diseases,” Larsen shared. “It’s fascinating to see how much our actions can influence the health and productivity of these animals.”
Looking ahead, the lab is excited about the future. “We’re starting to explore nutritional heat abatement strategies and innovative fan designs. Our longitudinal study is now entering its third generation, and we’re eager to see the long-term impacts of our interventions,” she concluded. “Ultimately, ensuring the comfort and health of calves is crucial for maximizing their production and longevity on the farm.”
