Source: Alberta Farm Animal Care
by: Dr. Karin Orsel, Faculty of Veterinary Medicine, University of Calgary
Bovine respiratory disease (BRD), accounts for most of the disease and deaths in Alberta feedlots and feedlots in North America. Although BRD is a multifactorial disease, it is mainly associated with bacterial pathogens. Therefore, BRD is treated using antimicrobials, potentially playing a role in the development of antimicrobial resistance.
Current management practices (e.g. moving calves from ranch to feedlot, purchasing calves through auction markets, and commingling cattle from multiple sources), increases the risk of BRD and makes it difficult to control. This increased susceptibility can be through exposure to new pathogens, as well as experiences of stress related to the transition from ranch to feedlot. Preconditioning using management practices to prepare calves to enter the feedlot, while keeping an eye on the economic value would help reduce the need for antimicrobials.
For our preconditioning study, we designed a protocol based on the scientific literature to decrease stress and prepare the calves as best as we can for the feeding phase. In February 2020, our preconditioning protocol was put into action during calving season, where calves received their first intranasal vaccines and later were processed on average at 60 days of age. The calves received another set of vaccinations and were knife castrated with pain medication. In late September we implemented a two-stage weaning stragedy, keeping the calves on pasture, fenceline separated from their dams and another set of vaccinations. To our surprise, calves were happy on pasture, exploring the waterers and hay provided and every now and then checking in with their moms at the fence. After one week, the calves were moved to a different location and housed in a pasture pen with feedbunks. We observed all feeding behavior, but it really didn’t take them long to figure out how to feed from the bunk with mixed silage/hay ration provided to them.
As a last step we will evaluate how our preconditioned calves perform in the feedlot, when mingled with conventionally raised calves evaluating both growth and health. We will compare our calves to regular auction derived calves, and evaluate the impact of mixing and mingling at different ratios. We are hoping our calves will outperform the auction calves, but also anticipate a learning opportunity for auction calves to quickly find the feeders and waterers.
Stay tuned for our final results being released early 2021!
This project is funded as part of the Major Innovation Fund focused on antimicrobial resistance and through the Alberta Agriculture and Forestry grant supported by Alberta Beef producers.
The team consists of Karin Orsel (PI), Ed Pajor, Frank van der Meer, Sean Thompson, Kathy Larson, Henry An and Trevor Alexander. It provides training opportunities for graduate students Abby Hodder, Morgan Louden and Michael Sydora.
