Transcript BVD control - Royal Veterinary College

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*
QuickScan 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
QuickScan
BVD
Interpretating the BVD QuickScan?
BVD-QuickScan is a combination of three tests,
• Bulkmilk test on BVD-virus (PCR): are there PI’s
in 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
Education
Persistence
Joe Brownlie © 2008 Royal Veterinary College