Chilly fall temperatures signal the start of calf-warming season, and with it comes some precautions for heat lamp users.

Heat lamps can be helpful, but they also can create the ideal breeding ground for bacteria such as salmonella, says Sheila McGuirk, veterinarian and professor at the University of Wisconsin School of Veterinary Medicine.

Calves pick up organic matter in the maternity pen and carry it with them to the warming area. A maternity-pen stay of just 10 minutes is long enough for a calf to pick up “flora” from the environment, McGuirk says. Under the warm glow of a heat lamp, this flora, along with moisture from the calf’s wet hair coat, encourages the growth of bacteria and other disease-causing organisms in the bedding.          

“We can grow salmonella out of that bedding repeatedly,” McGuirk said at the 2011 Dairy Calf & Heifer Conference.

On one farm visited by McGuirk, the temperature inside the warming pen was 90 degrees F. Newborn calves stayed in the pen for several days. A closer look at the calves’ manure showed that two out of three were shedding cryptosporidium oocytes.

A calf can get off to a good start without a heat lamp – even on those zero-degree days, contends McGuirk. She recommends that you remove the calf from the maternity pen promptly, dry her off and give her a warm, 4-quart helping of colostrum. Promptly move her to cold housing while the colostrum still has a warming effect.

According to the newly released Gold Standards III, good colostrum management is essential to maintain calf health, well-being and productivity. Learn more about the Gold Standards III at the Dairy Calf & Heifer Association website.

Heat lamps help grow bacteria