The Effect of Heat Stress on Dairy Calves February 28, 2022 The way we look at dairy calves has been less of a priority, but it shouldn’t be. While research in this area is less robust than on mature dairy cattle, we know that heat stress can have long-term impacts on calves. In the daily course of business on the dairy, the way we monitor heat stress and the impact it has on animals and outputs remains somewhat consistent. We monitor weather patterns, ventilation and cooling infrastructure, facilities, access to water and nutrition, and many other lifestyle-oriented details to – hopefully – minimize the negative impact on milk production. The way we look at dairy calves has been less of a priority, but it shouldn’t be. While research in this area is less robust than on mature dairy cattle, we know that heat stress can have long-term impacts on calves. Those include less dry matter intake and lower average daily gain; reduced long-term performance; and increases in mortality rates and decreased immunity. During a recent VES-Artex Academy Webinar, Dr. Sha Tao, associate professor of animal & dairy science at the University of Georgia, said that while definitive research on the topic is somewhat limited, dairies must do everything they can to limit calf exposure to heat stress in order to optimize both short- and long-term well-being. “It is necessary for us to mitigate heat stress during the summertime for the calves because the different management strategies can reduce the calves' body temperature,” Dr. Tao said. “I do think that that will improve the calves' welfare, and perhaps will influence the calves' immunity and health.” So, what are some potential strategies for alleviating heat stress in dairy calves? Dry Bedding + Shade In addition to minimizing the calf’s heat load during hot months with appropriate ventilation, ensuring those developing calves have access to shade and dry bedding can be critical in reducing ambient temperatures and humidity levels within the living environment. “From a management standpoint, I think we need to clearly utilize dry and clean bedding…because this could definitely affect the disease instance in the summertime,” Dr. Tao said. “It has been researched that providing shade can reduce the internal temperature in the hutches, and also can reduce the respiration rate of the calves.” Appropriate Nutrition and Water Access Simply, fresh water in the summertime – or during peak temperature seasons in other climates – is king. Additionally, increasing the water content of calf starter can also lead to better calf growth and development. “We need to replace water as frequently as we can,” Tao said. “And for calf starter, we want to keep that fresh. From some limited research, we know that it seems like an increase in the water content of the calf starter will reduce the dry matter content of the calf starter. It can improve the calf growth during the summertime.” To learn more about maximizing the well-being of the calves on your dairy from an environmental perspective, VES-Artex’s dairy experts are ready to assist you with a ventilation design for your facility or Calf Zone Pens. Our series of Calf Zone Systems are a great solution for providing calves optimal environment in both temperate, cold and hot climates. Reach out today for a consultation.