See also Bovine Viral Diarrhoea (BVD) Testing Guidelines
Indications for testing:
- Identification of exposure to BVDV
- Cattle older than 10-months-of-age once all colostral immunity has waned, or pre-suckling calves. Once infected, cattle will be viraemic for 10-14 days. About 2-4 weeks after infection is cleared, antibodies to BVDV will be produced and can be detected.
- Pooled antibody testing is possible in milk from lactating animals or 15 pooled sera from non-lactating animals. Pooled results are reported as a numerical S/P value. This is the sample value divided by the positive control. The S/P value can be compared with epidemiologically derived values to predict the likelihood of virus infection in the group.
- Individual ELISA values are reported as positive or negative.
- Foetal testing: Detecting BVDV antibody in the fetus indicates there has been viraemia of both the dam and fetus after 150 days gestation, when the fetus is immuno-competent and antibody has been formed. However antibody positive fetuses have not necessarily died because of BVDV infection. Nevertheless, antibody is a significant finding as it shows there was virus circulating in the herd.
- For surveillance, annual testing is recommended of either pooled serum samples from 15 yearling animals and/or a bulk milk antibody test on the lactating animals.
Species:
Bovine
Specimen:
Serum (10 ml)
Milk (50 ml)
Container:
Plain or gel tube (serum)
Plain sterile pot (mik)
Collection protocol:
Serum - standard venepuncture .
Milk – collect from a well-stirred vat one hour after milking finishes.
Special handling/shipping requirements:
Keep chilled.