Bovine respiratory disease (BRD) is a problem that is commonly identified in young, growing cattle (including non-feedlot cattle).
According to research published in the Journal of Preventative Veterinary Medicine (2016), Animal Health Research Reviews, the Journal of Animal Science and other studies in calves, it is not caused by a single pathogen, but is instead a complex disease resulting from a combination of external stressors.
Dr Sally Oswin – veterinary operations manager – technical development with Zoetis said these typically include weaning, mixing and handling which may precipitate disease in the presence of several different viral and bacterial agents that are common on most farms.
When young, growing animals suffer from subclinical disease (i.e. they show evidence of lung pathology at processing with no history of illness or treatment), the impact on the average daily gain has been shown to be a loss of between100 and 200 grams per day.
When clinical respiratory disease is evident, studies have shown the impact on production goes up to around 400 grams per day.
Of course, the most impactful result of cases of BRD in young cattle is when they are unable to overcome the disease and the outcome is mortality.
Dr Oswin said control of respiratory disease involves both changes to management and the use of effective vaccines.
“Evaluating what stressors are being placed on the animals is important; some of these will be outside your control such as inclement weather and the stress of weaning itself, but some stressors can be modified.
“Good planning is important, such as only weaning calves that are hitting an optimum weight, ensuring adequate clean space is available with good access to high quality feed and water, ensuring calves are not overstocked in pens, good parasite management and carefully choosing the dates of when to wean, based on forecasted weather conditions – all of which contribute to the reduction of stress on weaner calves.
“Once the stressors have been addressed, implementation of a vaccination program can be considered to reduce the risk of infectious agents complicating the weaning process.
“Vaccinating calves with a single dose Mannheimia haemolytica (MH) vaccine will provide rapid protection, within seven days, against respiratory disease in calves involving MH.”
Dr Oswin said vaccines do not exist for all the infectious agents implicated in the BRD complex, but studies have shown that the incidence of disease is increased when there are multiple pathogens present at once.
“Controlling just some of the pathogens present can reduce both the disease risk and the overall incidence of disease. Single dose vaccines have an important role to play here as there often isn’t time to implement a two-dose vaccination program to prevent BRD prior to the weaning risk period.
“A combination of a well-planned weaning process where conscious decisions are made to assess and remove stressors on young cattle and the use of highly effective single dose vaccines will have a significant impact on the risk of a respiratory disease outbreak in young cattle” Dr Oswin said.
By weaning age, most calves will carry the dormant form of the bacteria Mannheimia haemolytica (MH) in their throat. When the animal is placed under stress and/or encounters other viral respiratory pathogens, the MH in the throat become activated and cause a bacterial pneumonia.
Dr Oswin said Bovi-Shield MH-One is the only vaccine that provides on-farm protection from one injection. The patented technology uses a high potency freeze-dried antigen and unique proprietary adjuvant that are simply mixed on farm prior to use.
Zoetis data shows that Bovi-Shield MH-One works fast, providing protection in seven days which makes it a highly convenient product when a rapid onset of protection is required.
