Reducing bovine respiratory disease (BRD) in developing dairy heifers is important from both an animal welfare and economic standpoint, regardless of the season or climate. Calf pneumonia can strike any time of year and puts future herd productivity at risk. A study tracking the effects of respiratory disease on Holstein calves showed those with a history of respiratory disease are two-and-one-half times more likely to die prior to delivering their first calves, as compared to calves that remained healthy.1
Bovine respiratory disease associated with Mannheimia (Pasteurella) haemolytica, in particular, is recognized for its severity and rapid onset in dairy calves, so vaccinating to prevent BRD is a smart herd health management protocol. To get the most protection vaccines can offer, producers need to remember that other factors such as stress, nutrition and weather should all be taken into account to ensure that vaccine programs provide the best result.
As summer heats up, so does the likelihood of calves experiencing heat stress. One of the challenges of heat stress is that it limits an animal’s ability to build an immune response, and there is no way to predict which animals are more sensitive to its effects. Administering vaccines in excessively hot or humid conditions should be avoided whenever possible. It’s always better to vaccinate early in the day when air temperatures are cooler. And that goes for both calves and cows. In the summertime, this means avoiding vaccinating cattle if the temperature is above 85 degrees with humidity above 40%, or at higher temperatures with lower humidity.
Heat stress can also lower an animal’s natural barriers to bacteria.2 That’s why it’s also important not to overload cattle with gram-negative vaccines in the heat of summer. For the best advice regarding summertime vaccinations and timing, consult with your herd veterinarian.
Additional Vaccination Tips:
• Properly store products.
• Administer vaccines according to label directions.
• Use good hygiene when administering vaccines.
• Keep appropriate treatments like epinephrine on hand to quickly address any adverse animal reaction.
By Doug Scholz, DVM, Director of Veterinary Services, Novartis Animal Health