Ask the Expert: Heat Abatement for Calves
Posted on November 8, 2012 in Starting Strong - Calf Care
Dr. Becky Brotzman, DVM, is the associate outreach specialist for the Food Animal Production Medicine section at the University of Wisconsin-Madison School of Veterinary Medicine.
Q: “I am concerned with heat stress in my calves. I currently use both hutches and a calf barn for raising my pre-weaned calves. What are my options for heat abatement in these different styles of calf housing?”
A: Heat stress is a problem for calves as well as cows. Young calves are not able to regulate body temperature as well as adult cattle. We have several things we can do to provide relief from the heat for our nursing calves.
Hutches made of either translucent or opaque materials will get hot sitting in the summer sun. Consider locating hutches in the shade of a tree line or a tented shade cloth. Be sure to keep hutches spaced far enough apart to prevent calf-to-calf contact, and distanced from buildings and obstructions to prevailing winds. Open all vents on your hutches. Newer models have large hatch openings in the back to help clean and cool the air within the hutch. Propping up the corners of the hutch will help improve air quality within the hutch. A run on the front of the hutch or tether to the outside will allow the calf more space to take advantage of a breeze coming from another direction to help cool her off.
Nursery calf barns should be properly positioned, ventilated and designed to help prevent heat stress. An east-west orientation will decrease the amount of direct summer sun on the roof, decreasing heat radiation into the barn and allowing for better utilization of prevailing winds. Keep sidewalls as open as possible to capture these winds. Use open back and front panels to improve air quality within calf pens and solid dividers between calves to reduce disease transmission. Place individual pens 2 to 4 feet from the sidewall to give calves space to get out of the sun if the barn doesn’t have a wide roof overhang. A shade cloth along the sidewall will decrease sun exposure within the barn. Depending on your location, prevailing winds are calm for 4 to 14 percent of the time in the middle of summer. To ensure fresh air delivery into the barn, use a properly designed supplemental positive pressure tube system to uniformly distribute fresh air at an appropriate target speed and location within the calf pens. Recirculating fans placed above the pens are useful for cooling calves, improving comfort, and boosting feed efficiency and growth (Hill et al., 2011, J. Dairy Sci.).
In either hutches or nursery calf barns, always have plenty of clean, fresh water available for calves to drink. Give special attention to calves with scours and offer them fresh water and electrolytes twice daily as dehydration occurs more quickly in the heat. Keep calves dry and well-bedded to promote growth and health through good hygiene and air quality. Wood shavings bedding promotes lower air bacterial counts and fewer flies than straw while providing an absorbent, comfortable resting surface safely used in warm temperatures when calves do not need to nest (above 50˚F). Place hutches and calf pens on a well-drained base, such as 12 inches of pea gravel with a tile drain running through it (be sure to follow conservation regulations). Producers using this base claim to use half as much bedding as when keeping calves on a concrete base, realizing a large cost savings.
For more information on calf and heifer facility design, check out the “Wisconsin Blueprint” and Virtual Tours on The Dairyland Initiative website. Our team of veterinarians in the Food Animal Production Medicine section at the UW-Madison School of Veterinary Medicine is available for consultation in collaboration with your local veterinarian and nutritionist.
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Starting Strong - Calf Care