Source: Beef Cattle Research Council
Vaccination is a proven tool for disease prevention. Vaccination recommendations vary by region and by farm as the environment, production, and management practices can increase or decrease the amount of risk cattle are exposed to. Disease exposure occurs in numerous places including community pastures, fenceline contact with neighbouring cattle, auction markets, and breeding cattle, such as bulls, purchased from other herds. However, vaccinating breeding females for reproductive disease and calves for respiratory disease are recommended practices across Canada. A vaccination program should be developed in consultation with a veterinarian who can determine which ones are necessary for your area.
In western Canada, one in ten producers surveyed are not vaccinating their cows for infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea virus (BVD) (Waldner et al., 2019) and more than a quarter of producers do not vaccinate cows for other reproductive diseases (Beef Cattle Research Council, 2019). One third of Ontario producers do not vaccinate their cows for BVD and far fewer vaccinate for other reproductive diseases. In Atlantic Canada, 27% of producers reported not administering general vaccinations. This leaves herds vulnerable.
Why Vaccinate for BVD?
When a cow is infected with BVD in early pregnancy, the offspring may be born persistently infected (PI). PI animals are generally considered to be the primary source for transmission of the virus.
BVD infection can lead to poor conception rates and both BVD and IBR can cause abortions in cattle. Blood tests show exposure to these diseases is common in unvaccinated herds. There is evidence from several experimental trials that these vaccines are effective. When multiple studies are analyzed, the outcome shows that on average there is an 85% decrease in fetal infection, 45% decrease in abortions and a 5% increase in pregnancy rates in BVD-vaccinated herds. Field studies in western Canada have shown improvement in pregnancy rates and a decrease in abortion rates for vaccinated cows compared to unvaccinated cows on community pastures.
In the U.S., total annual losses have been estimated at $20 million for every million calves when modeling for low-virulent BVD strains and $57 million when modeling for a high-virulent BVD strain (Houe, 1999). If we take Canada’s breeding herd at 3.9 million beef cows, estimated BVD losses here would be in the range of $78 and $220 million (Clarke, 2014). In New Zealand, the prevalence of BVD and its economic cost to the industry are also well defined. It is estimated that at least 65% of beef herds have at least one case of BVD. The annual losses for beef famers are estimated at NZD $3,000-$9,000 per 100 cows in infected herds.
Motivation to vaccinate
Waldner et al. (2019) found that producers reported their motivation for using vaccines for reproductive diseases was to prevent a wreck, even if they had no issue in the past. Seventy percent of herds reported the economic benefits of using the vaccine were considered when deciding what vaccines to use.
The Cost Benefit of BVD Vaccinations tool allows producers to input their herd size, expected price, animal weights, cost of vaccine and labour to see the potential savings from vaccinating cattle for BVD specifically from changes in reproductive performance caused by abortions.
Beef Cattle Research Council (2019). Adoption Rates of Recommended Practices by Cow-Calf Operators in Canada. Calgary, AB: Canfax Research Services. Available at:http://www.beefresearch.ca/files/Adoption_Rates_of_Recommended_Practices_by_Cow-Calf_Operators_in_Canada_-_March_2019_Final.pdf
Clarke, R. (2014). BVDv eradication still a North American pipe dream. Western Canadian Association of Bovine Practitioners. Available at:http://www.canadiancattlemen.ca/2014/12/31/bvdv-eradication-still-a-north-american-pipe-dream/
Erickson, N. and Larson, K. (2017). Cost-Benefit Comparison of BRD and BVD Vaccinations. Unpublished.
Houe, H. (1999). Epidemiological features and economical importance of bovine virus diarrhoea virus (BVDV) infections. Veterinary Microbiology 64(2):89-107.
Theurer, M. E., Larson, R. L., and White, B. J. (2015). Systematic review and meta-analysis of the effectiveness of commercially available vaccines against bovine herpesvirus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza type 3 virus for mitigation of bovine respiratory disease complex in cattle. Journal of the American Veterinary Medical Association, 246(1):126-142.
Waldner, C.L., Parker, S., and Campbell, J.R. (2019). Vaccine usage in western Canadian cow-calf herds. Canadian Veterinary Journal 60(4):414-422