Prepare dairy calves for cool-weather stress

Cooler weather could put a chill on dairy producers’ bottom lines if they aren’t prepared for the threat of pneumonia and bovine respiratory disease (BRD). Researchers from the University of Wisconsin-Madison state that early BRD illness can affect a producer’s bottom line due to production losses later in the cow’s life — that is, if a calf isn’t lost to a chronic illness at a young age.

“Cool-weather months in late fall, winter and early spring are a peak threat for BRD and pneumonia,” said Dr. Bruce Nosky, manager, Veterinary Services, Merial. “The disease is costly initially due to treatment, veterinary and labor costs, but it also takes its toll over time by negatively influencing a calf’s potential to be a productive and profitable member of the herd.”

A 2002 study showed that body weight of BRD-affected heifers was estimated to be reduced by 22 pounds at 3 months old, and up to 63 pounds from heifers 14 months old. It also found that first lactation was reduced and first calving age was delayed by half a month. This can mean delayed and reduced production for the producer.

“When calves get sick, not only will their production suffer due to initial losses, but just as importantly, they may never catch up in weight and production to other calves that do not have the disease,” Nosky said. “The producer is then paying for treatment as well as the lost productivity down the road in areas that have a direct relationship with the cow’s profitability.”

Prevention of BRD includes breaking the disease cycle through proper management practices and increasing herd immunity with a vaccination program, Nosky said. The two bacteria often associated with BRD are Mannheimia haemolytica and Pasteurella multocida. These bacteria inhabit the upper respiratory tract of normal, healthy calves causing no problems, but when calves are put under stress, such as fluctuating colder temperatures, Mannheimia haemolytica and Pasteurella multocida can migrate to the lungs and pneumonia can occur. Nosky said the stress from factors like weaning, cold weather, crowding or transport can be the final additive factor that completes the disease complex — resulting in BRD.

“With cold weather on its way, protecting against Pasteurella with a vaccination program and proper management practices can help dramatically cut down on sickness in young calves and help prevent possible productivity losses after the season,” Dr. Nosky said.

To help avoid BRD and other diseases this winter, Nosky recommends the following when caring for young calves:

  1. Utilize an immunization program to vaccinate against bacterial pneumonia caused by Mannheimia haemolytica and Pasteurella multocida, and to help keep herds healthy and productive.
  2. Vaccinate prior to stress, such as weaning or transporting.
  3. Provide proper housing and ventilation to help prevent diseases from spreading. Individual calf hutches or box pens that prevent nose-to-nose contact should be used to avoid outbreaks.
  4. Supply proper nutrition and hydration to keep calves healthy and disease-free.
  5. Feed an adequate amount of colostrum to newborn calves within 12 hours of birth.

“Healthy calves grow up to be productive cows,” Nosky said. “By using proper management practices and a vaccination program that includes a Pasteurella vaccine that helps aid in the prevention against both Mannheimia haemolytica and Pasteurella multocida, producers can help improve the health and efficiency of their calves — helping to ensure they will be more productive cows.”

Merial provides a comprehensive range of products to enhance the health, well-being and performance of a wide range of animals. Merial employs approximately 5,000 people and operates in more than 150 countries worldwide. Its 2007 sales were nearly $2.5 billion. Merial Limited is a joint venture between Merck & Co., Inc. and sanofi-aventis. For more information, please see