Bovine viral diarrhoea (BVD) is a disease caused by bovine pestivirus. Infection in non-pregnant animals results in diarrhoea, reduced conception rates and immuno-supression. Infection in pregnant animals can result in abortion, the birth of stunted calves or calves born with ‘persistent infection’ (PI). Infection during the first third of pregnancy can compromise the development of the foetal immune system and the calf is unable to eliminate the virus. When the calf is eventually born, it produces large amounts of virus throughout its life. The calf may appear normal or be stunted but it is likely to succumb to fatal mucosal disease later in life. If PI animals come into contact with breeding cows, the cycle of infection continues with the creation of more PIs. Avoiding infection of the unborn calf and the detection and removal of PI calves from the herd are critical to the control and eradication of BVD in cattle.
Protocols Beef Herds
Level 1 - Establishing health status Blood samples are collected from 10 adult cows, irrespective of herd size, plus all breeding bulls and tested for antibody. If results are positive the herd enters Level 2. If results are negative a statistical number of youngstock are tested for BVD antibody and if these results are negative the herd enters Level 3.
Level 2 - Improving health status through disease reduction strategies A PI search is carried out on all stock over 30 days. Samples can be pooled in groups of 10 for virus testing and cattle submitting to positive pools should be blood tested for antigen. This can be carried out on the blood sample already submitted. All PIs identified must be removed from the herd. Calves are tested for virus for a 12 month period from the removal of the last PI. If all the results are negative the herd can progress to level 3.
Level 3 - Monitoring and maintaining health status To monitor for freedom from disease a yearly blood test for antibody from a statistical number of youngstock aged 9-18 months is carried out.
Herdsure provides the option for a herd to become BVD disease free accredited. Herds will be eligible to apply for CHeCS accreditation provided they achieve negative results with appropriate animals tested and comply with defined biosecurity rules.
Herds entering Level 3 direct from Level 1 will be eligible for BVD accredited status after 12 months testing at Level 3, provided all test results are negative.
Herds entering Level 3 from Level 2, following a PI search, will be eligible for BVD accredited status after 24 months testing at Level 3, provided all test results are negative.
Herdsure issues Certificates of accredited health status and can issue individual animal sale cards if requested.