Download presentation
Presentation is loading. Please wait.
Published byNathan Simpson Modified over 9 years ago
1
B.V.D. Bovine Viral Diarrhoea Virus
2
BVD Highly contagious viral infection Most infections have no clinical signs Sero-conversion, virus elimination and life-long immunity
3
BVD Reproductive effects Infection during pregnancy Effect on foetus Month 1 Embryo death Month 2-4Persistent Infection (PI) Month 5-9abortions, deformities, etc
4
BVD Reduced immune function Immuno-suppression Enteric/Gut Respiratory Reproductive Mastitis Mucosal Disease low morbidity / high mortality
5
BVD Significance of PI Most important source of infection in herd May not be present when you search for it Frequently unthrifty May succumb to mucosal disease May live for a long time in herd Always antibody negative
6
BVD Economics of infection Initial outbreak €19 - €600 per cow Herd level €31 -€100 / cow / year National level €15 - €20 / cow / year
7
BVD Diagnosis of individual AntibodySero-positive for life VirusBlood Ear punch may need to be confirmed 3 weeks later
8
BVD Herd level screening Adult herd DairyBulk milk whole herd for Ab and Virus BeefBleed 15 non-vaccinated from each group for Ab and Virus(pooled?) Young stock Bleed 5-10 home bred non-vaccinated 8-24 month old from each separate group for Ab and Virus
9
BVD Herd level diagnosis Whole herd virus check2 year project Calf ear punch National scheme may be launched in near future Bulk Tank Milk:- AntibodyNon-vaccinated herd see appearance of Ab Vaccinated herd -monitor levels for spikes VirusShows presence of circulating virus in milking herd
10
BVD Risk factors for introduction PurchasePI animal, Dam with PI, Animal contactBoundaries, Shows etc Visitors Equipment Embryos
11
BVD Ideal world Closed herd No purchase of pregnant animals Quarantine / testing of new Avoid fence contact Limit access on farmdisinfection, clothing
12
I.B.R. Infectious Bovine Rhinotracheitis
13
IBR Respiratory disease emerged in California in early 50’s UK in early 60’s Mainland Europe in early 70’s Ireland in 1989
14
IBR Fever4-5 days Apathy Anorexia (Milk drop) RespiratoryRed nose, plaques, cough, nasal discharge, conjunctivitis ReproductionAbortion (direct and indirect) Death
15
IBR Establishes life-long latency in nerve tissue Reactivation following stresses such as:- transport, calving, weather, over-crowding, corticosteroids.
16
IBR Economics of infection Reduction in milk production in antibody positive cows c. 0.92kg / day in one study 150kg / year (2%) in another Loss of genetics value
17
IBR Diagnosis of individual Virus isolation Deep intra-nasal swabs in clinically non-affected animals Antibody Serum, milk Antibody does not eliminate virus, infected for life Can do paired blood antibody 3 weeks apart to demonstrate rising levels to indicate disease
18
IBR Herd level screening Bleed 5-8 animals for antibody from each separate group Bulk milk antibody monitor for arrival or changes in Ab level
19
IBR Control Do nothing Vaccinate in face of outbreak Vaccinate to control clinical signs Eradicate
20
IBR Bio-security Risk factors Purchase Animal contactBoundaries, Shows etc Visitors Equipment
21
IBR Ideal world Closed herd No purchase of animals Quarantine / testing of new Avoid fence contact Limit access on farmdisinfection, clothing
22
IBR Vaccintion Live Inactivated Evidence divided on protocols
23
Johnes Mycobacterium Avium Paratuberculosis MAP
24
Chronic granulomatous enteritis of ruminants Diarrhoea, weight loss, reduced milk yield, death MAP ingested from environment, colostrum or milk
25
MAP Economics of infection Reduced milk production (600 – 2,200kg/lact) Reduced constituents (fat, protein) Increased mortality Weight loss Premature culling Reduced slaughter value Consumer worries
26
MAP Diagnosis of individual Culture Faeces, milk, bulk tank, semen, dust PCR Semi-quantitative, Antibody Accuracy of ELISA (Se and Sp concerns) False positives post TB testing
27
MAP Herd level screening Culture Environmental dust, Bulk tank milk BTM AntibodySe concerns (0.07 – 0.94) PCRlower level in milk No test suitable to demonstrate freedom from infection.
28
MAP Risk factors Introduction Purchase, manure/slurry, water Transmission Calving pen hygiene, udder cleanliness, colostrum from positive cows, exposure to faeces, mixed age housing
29
MAP Control Danish system traffic light system Low riskGreenlast 4 tests neg. High riskRed2 or 3 pos from last 4 cull at end of season Yellowseparate calving pen remove calf immediately colostrum from green cows only group by age milk replacer and separate housing
30
What can we do for you? Interpret diagnostic tests Plan herd diagnostic assessment Bio-security advice Vaccination planning
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.