This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the May 2022 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
After last summer’s pasture conditions and last winter’s feed costs, it’s safe to say that many cow-calf producers are facing the upcoming grazing season with some anxiety. Some are looking for new grazing arrangements, opportunities to trim input costs, or both. No single solution can solve every challenge for every operation, but nearly all decisions have trade-offs. Using a community pasture or other shared grazing arrangement may reduce pasture costs but mixing different herds can spread reproductive (and other) diseases. This risk is magnified if you’re tempted to save costs this year by skimping on your vaccination program.
The February and March editions of this column drew from a large beef cow productivity study that happened to coincide with the 2001-02 drought in Western Canada. That study also revealed how important vaccination programs are to maintaining reproductive performance. These results were published in Livestock Science 163:126-139 and Theriogenology 79:1083-1094; 81:840-848.
What They Did:
To recap, Dr. Cheryl Waldner and her colleagues from the Western College of Veterinary Medicine studied the productivity of over 30,000 beef cows in over 200 well-managed herds in Alberta, Saskatchewan and B.C. Participating producers individually identified each cow and calf, recorded all calf births (including abortions), maintained an active veterinary-client-patient relationship, had good animal handling facilities, pregnancy tested all breeding females, had a veterinarian evaluate all herd bulls, had an established spring or summer breeding season (i.e., didn’t calve year-round), and worked with the researchers to collect the needed samples and data.
As part of the study, they compared the pregnancy and abortion rates in these herds, based on whether they used community pastures and whether they vaccinated their cows against BVD and IBR before the breeding season. These two diseases don’t just affect calves; they can also reduce reproductive success in cows. Continue reading
