Respiratory issues are a leading cause of death in calves
While respiratory issues can affect any animal at any age, it tends to be more common in younger animals.
Dr. Craig Payne, University of Missouri Extension Veterinarian, said the USDA National Animal Health Monitoring System survey suggests respiratory issues are the leading cause of mortality in pre-weaned beef calves 3 weeks of age or older. Furthermore, surveys of cow-calf producers from the United States and Canada suggest that respiratory disease in preweaning beef calves is recognized annually on 18 percent to 36 percent of operations.
Payne said studies of pre-weaned calf pneumonia suggests no one pathogen predominates, and the pathogens involved are those commonly found in cattle that have respiratory disease in other phases of production, including viruses such as Infectious Bovine Rhinotracheitis (IBR), Bovine Respiratory Syncytial Virus (BRSV), Bovine Virus Diarrhea Virus (BVDV) and bacteria, such as Manheimia haemolytica, Pasteurella multocida and Histophilus somni.
While pathogens are present for most calf respiratory diseases, oftentimes an environmental stressor is what lights the fuse.
“Calves under stress, in close quarters and comingled with those from other places tend to be the most at-risk types. Unfortunately, many times all of these stresses come together at the same time, causing the outbreaks we always fear,” University of Missouri Extension Livestock Field Specialists Andy McCorkill explained. “The pathogens are commonly present, it just takes a stressor to bring them to the forefront. Usually, this happens around weaning, shipping, backgrounding or upon arrival at the feedlot.”
The level of immunity will play a factor in respiratory ailments. Payne explained there are two common ages that respiratory issues typically appear in calves related to their immune level.
“A large study using birth and health records from over 110,000 calves at the U.S .Meat Animal Research Center during a 20-year period revealed there are two time periods when preweaning calf pneumonia was most common; around 20 days of age and again at 140 days of age, with the latter being more common. It is believed calves with respiratory disease at 20 days of age are most likely a consequence of failure of passive transfer, meaning some calves failed to receive sufficient passive immunity from the dam’s colostrum and therefore are at higher risk of disease. The opposite is true for cases that occur around the later time period. These calves likely received sufficient passive immunity, but it drops below a protective level with age.”
There are some strategies that can aid producers in boosting calf immunity, or at least manage it.
“For stocker/backgrounding operations or others where cattle are frequently coming and going, it’s advisable to put new arrivals in a lot away from longer held cattle to reduce nose contact and the risk of disease transmission. A proper plan of nutrition will help and spreading out stresses such as castration and dehorning from weaning will help keep the immune system from being overloaded,” McCorkill advised.
Calves suffering from respiratory ailments will typically display symptoms of depression, have a decreased appetite and will be slow to get to the feed bunk, have an increased respiratory rate and elevated temperature, and nasal discharge. A producer’s herd veterinarian should be contacted immediately if respiratory ailments are suspected so they can come up with a herd specific treatment plan. As always, prevention is the best cure.