B.V.D. Bovine Viral Diarrhoea Virus

BVD Highly contagious viral infection Most infections have no clinical signs Sero-conversion, virus elimination and life-long immunity

BVD Reproductive effects Infection during pregnancy Effect on foetus Month 1 Embryo death Month 2-4Persistent Infection (PI) Month 5-9abortions, deformities, etc

BVD Reduced immune function Immuno-suppression Enteric/Gut Respiratory Reproductive Mastitis Mucosal Disease low morbidity / high mortality

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

BVD Economics of infection Initial outbreak €19 - €600 per cow Herd level €31 -€100 / cow / year National level €15 - €20 / cow / year

BVD Diagnosis of individual AntibodySero-positive for life VirusBlood Ear punch may need to be confirmed 3 weeks later

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

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

BVD Risk factors for introduction PurchasePI animal, Dam with PI, Animal contactBoundaries, Shows etc Visitors Equipment Embryos

BVD Ideal world Closed herd No purchase of pregnant animals Quarantine / testing of new Avoid fence contact Limit access on farmdisinfection, clothing

I.B.R. Infectious Bovine Rhinotracheitis

IBR Respiratory disease emerged in California in early 50’s UK in early 60’s Mainland Europe in early 70’s Ireland in 1989

IBR Fever4-5 days Apathy Anorexia (Milk drop) RespiratoryRed nose, plaques, cough, nasal discharge, conjunctivitis ReproductionAbortion (direct and indirect) Death

IBR Establishes life-long latency in nerve tissue Reactivation following stresses such as:- transport, calving, weather, over-crowding, corticosteroids.

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

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

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

IBR Control Do nothing Vaccinate in face of outbreak Vaccinate to control clinical signs Eradicate

IBR Bio-security Risk factors Purchase Animal contactBoundaries, Shows etc Visitors Equipment

IBR Ideal world Closed herd No purchase of animals Quarantine / testing of new Avoid fence contact Limit access on farmdisinfection, clothing

IBR Vaccintion Live Inactivated Evidence divided on protocols

Johnes Mycobacterium Avium Paratuberculosis MAP

Chronic granulomatous enteritis of ruminants Diarrhoea, weight loss, reduced milk yield, death MAP ingested from environment, colostrum or milk

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

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

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.

MAP Risk factors Introduction Purchase, manure/slurry, water Transmission Calving pen hygiene, udder cleanliness, colostrum from positive cows, exposure to faeces, mixed age housing

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

What can we do for you? Interpret diagnostic tests Plan herd diagnostic assessment Bio-security advice Vaccination planning