BVD virus (BVDV) is arguably one of the most important infectious agents of cattle. BVDV causes a wide variety of clinical syndromes in cattle including:
- infertility
- abortion
- congenital defects in calves
- weak and dying calves
- production losses from poor performance
BVD virus is widespread in Western and Eastern Canada. A study in SK and AB in the 1990s found that 41% of beef cattle sampled had antibodies to BVDV. Almost two-thirds of all farms had cattle that had been exposed to BVD.
Losses in the Cow Herd
A landmark investigation into economics of BVD virus in cowherds was published in 2002 by a group of researchers from the United States. Their data showed that the negative effect of PI calves on pregnancy percentage, pre-weaning mortality and weaning weights, varied between $14.85 US and $24.84 US depending on the year investigated. For a 200 cow beef herd, these costs would be $2970 and $4968 US in direct economic costs.
Losses in the Feedlot
Feedlots incur large economic costs due to BVD as well. The PI calves often die in the feedlot. Those that do not die have drastically decreased performance and increased health costs.
A recent large feedlot study in the US, quantified how much PI cattle can cost a feedlot. They tested every animal arriving at the feedlot for one full year - over 21,000 head of animals. They found that 0.3 percent were PI calves. They then calculated performance costs, sick animal costs and dead costs between pens that had PI calves in them, non PI pens living beside PI pens and clean pens. Due to the immunosuppressive effects of BVD virus, they found a huge impact on "normal" calves that were pen mates of, or living beside PI calves;
Every calf exposed to BVD virus had over $61 in increased costs compared to calves not exposed.
