You can’t control everything on your operation. But you can take preventive steps to protect calves from bovine respiratory disease (BRD), long before you ever reach for antibiotics.
“Work with your veterinarian to develop a preventive health program that best maximizes or improves cattle health and prepares animals for the next phase of production,” advised DL Step, DVM, Boehringer Ingelheim.
A good preventive program, which can reduce the number of calves that succumb to BRD, lessen the severity of clinical signs and decrease the number of animals that develop complications, often includes the following steps.
Ensure colostrum delivery for passive transfer of immunity
A newborn calf has no antibodies circulating in its system to fight off infection. That’s why it’s critical for the calf to ingest adequate amounts of high-quality colostrum, or the antibody-rich first milk from the dam soon following birth, preferably within the first eight hours of the calf’s life.
What happens in those first hours can have short- and long-term impact on calf health. Compared with calves that received adequate colostrum, “a beef calf that didn’t is over three times more likely to experience an illness such as respiratory disease in the feed yard,”1 reported Dr. Step. “We can also see more enteric problems, especially in the first few weeks of life, as well as respiratory disease during the cow/calf phase of production.”
Extend immunity with vaccination
For calves, respiratory vaccines are important to stimulate the adaptive or acquired immune system and help the calf develop a memory response. “If or when the animal comes in contact with those respiratory pathogens (disease-causing agents) in the future, the memory response is activated, so the immune system can respond more rapidly,” said Dr. Step. While this doesn’t necessarily prevent infection, it can reduce the severity of clinical signs.
A number of factors can lead to stress in cattle, such as transport or shipping, fluctuations in temperature and nutritional changes. Stress can suppress an animal’s immune system and open the door for viruses and bacteria to invade the respiratory tract.
“Viruses can destroy normal respiratory tract mechanisms, such as the cilia that help move dust, debris and mucus out of the lower airway,” explained Dr. Step. “Many bacteria are normal inhabitants of the upper respiratory tract, but damage to these respiratory tract mechanisms and stress can allow those organisms to enter the lower respiratory tract, which can lead to pneumonia.”
Commingling, or mixing animals from different sources with unknown health histories, can also cause stress and expose animals to disease-causing agents (respiratory pathogens). “It’s like putting a bunch of school children together after vacation,” suggested Dr. Step, “shortly after the group is back together in school, illnesses often develop.”
Use antibiotics thoughtfully
Despite all your best efforts to prepare calves, there are still times when the metaphylactic use of antibiotics makes sense. “Metaphylaxis can help minimize the number of calves that get sick, and therefore, the number that die,” reported Dr. Step.
“Can we make an animal healthier by the time it leaves the cow-calf operation?” asked Dr. Step. “Yes we can.” It’s just a matter of working with your veterinarian to create a BRD prevention program that works for your operation.