BVD control How are herds infected? Joe Brownlie © 2008 Royal Veterinary College
'Average' Herds …. . with PI? ? Joe Brownlie © 2008 Royal Veterinary College
'Average' Herds …. with Immune cows Joe Brownlie © 2008 Royal Veterinary College
'Average' Herds …. but naive Joe Brownlie © 2008 Royal Veterinary College
How do you get started? Joe Brownlie © 2008 Royal Veterinary College
Diagnostic tools offered to farmers* Quick. Scan BVD • combination of three tests • Bulk milk test on BVD-virus (PCR) • Bulk milk test on BVD-antibody • blood test for BVD antibodies on spot check (n=5) in the young stock Joe Brownlie © 2008 Royal Veterinary College
GD Quick. Scan BVD Interpretating the BVD Quick. Scan? BVD-Quick. Scan is a combination of three tests, • Bulkmilk test on BVD-virus (PCR): there PI’s in are this milking herd ? • Bulkmilk test on BVD-antibody: has there been BVD contact in the last years ? • Blood test on antibody in youngstock ( n=5): have youngstock recent contact with BVD virus (last months i. e. active BVD on farm? ) Joe Brownlie © 2008 Royal Veterinary College
GD Programme BVD-virusfree BVD PI not found or removed: During 10 month tests of all new calves ( > 1 month ) No PI’s: - BVD-free (certificate) PI’s found: - removal; - prolounged period Joe Brownlie © 2008 Royal Veterinary College
Probability on PI Youngstock with antibody: percentage herd with PI 3/5 11 4/5 21 5/5 68 Joe Brownlie © 2008 Royal Veterinary College
Conclusions • Good diagnostic tools and vaccines are available – use wisely & strategically • Control programs should be designed to reduce risk and consequences of human error – establish vet/farmer partnership • Commitment of all shareholders is essential – try to build neighbour commitment Joe Brownlie © 2008 Royal Veterinary College
Herds Don’t Stay Still Joe Brownlie © 2008 Royal Veterinary College
What will we need to make it work? • initial screen e. g. bulk milk testing for BVDV & young stock testing • if +ve, find & cull the PI animals • continued monitoring • expert advice to you • recognised value of BVD accreditation Joe Brownlie © 2008 Royal Veterinary College
What do vets hope to achieve? • recruit many farms to BVD control scheme • take all farms through to BVDV freedom • collect information to show benefit of scheme • launch regional/national scheme Joe Brownlie © 2008 Royal Veterinary College
What advantages we hope for farmers? • BVDV freedom • Health and welfare advantages • clear cost benefit • benchmarking advantage • become a major source of BVD-free animals Joe Brownlie © 2008 Royal Veterinary College
We hope you will join us in this ‘pioneering’ BVD Control scheme – you are key players? Already, there are established some BVDv-free herds in the UK. Usually 1 -3 year control programme. Joe Brownlie © 2008 Royal Veterinary College
What make diseases important? • Acute and explosive • Chronic and disabling • Untreatable • Severe even fatal • Widespread, intermediate vectors • Persistent infection • Zoonotic Joe Brownlie © 2008 Royal Veterinary College
Overall Summary – BVD: signs, threat & infection FARMERS • Level of infection – Dairy – 79% of farmers say that they have discussed BVD with their vet but only 11% say that they have BVD. • Measures – More than ½ farmers (57%) feel they take no specific measures against BVD with just 23% mentioning vaccination. • Impact – Most farmers (72%), however, feel that there is no real impact of BVD. VETS • Level of infection – Perceived to be higher by vets than by farmers. Dairy – vets say ¾ (76%) dairy tested and ¾ are positive (71%). Beef – 29% have been tested of which 60% have BVD. • Measures - Vets view vaccination as the main tool against BVD (78%). Testing is also useful (48%). • Impact – Vets feel that the main impact of BVD is financial (48%) and infertility (41%). Joe Brownlie © 2008 Royal Veterinary College
Education Persistence Joe Brownlie © 2008 Royal Veterinary College
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