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Johne’s Control: An Atlantic Canada Success Story. Greg Keefe DVM MSc MBA Atlantic Veterinary College University of Prince Edward Island. Overview of Disease. Photos courtesy of www.johnes.org. Johne’s Disease (Yo-nees), Paratuberculosis
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Johne’s Control: An Atlantic Canada Success Story Greg Keefe DVM MSc MBA Atlantic Veterinary College University of Prince Edward Island
Overview of Disease Photos courtesy of www.johnes.org • Johne’s Disease (Yo-nees), Paratuberculosis • Mycobacterium avium subspecies paratuberculosis (MAP) • Chronic, Infectious Enteritis • Milk production losses • Premature culling • Reduced fertility • Diarrhea and emaciation
Calf High risk of infection Fecal oral infection Colostrum risk No outward signs Heifer Incubating Low risk of infection/shed No overt signs Lower production Clinical cow Shedding Chronic weight loss Diarrhea Lower production Infected cow May shed No overt signs Lower production Poor Reproduction Median age between infection and shedding is 5 years Most animals get culled for low production before clinical
All Herds Infected Herds Infected Cows Infectious Cows Affected Cows
JD research in Atlantic Canada • 15 years ago estimated that the prevalence was 17% of herds and about 2.5% of cows • Blood test of 30 cows in each of 90 herds • Focus on diagnostic test evaluation • Determined the limitations of blood or milk testing • 20-40% of infectious cows • 10-20% of infected cows
Atlantic Johne’s Disease Initiative • December 2009 industry meeting • Economic Loss • Decreased milk production • Culling and reproduction • Cattle Movement • Infection reservoir cows • Movement = spread • Market Access • Competitive advantage for local genetics
Atlantic Johne’s Disease Initiative MQM lab is USDA proficiency tested for 5 Johne’s diagnostics • Program Pillars • Education • Infection control & prevalence reduction • Research
Education Economics Biosecurity Awareness Heifers • Website (www.atlanticjohnes.ca) • Mailings and media • 47 certified veterinarians • Delivering 1 on 1 farm specific management plan education to dairy producers
Control Program Herd Categorization Environmental Culture (EC) Voluntary Fully funded Risk Assessment& Management Plan (RAMP) Required if herd tested Fully funded Cow Testing Voluntary - EC positive herds eligible Partial funding
Herd categorization procedures Environmental culture (USDA) Whole Herd Milk ELISA (Ontario) DHI milk samples Cow data to cull very high titre animals False positive results – culling unnecessarily Risk that farmers rely on culling rather than “management” • Manure samples from 6 sites on farm • Cheaper than testing every cow • No immediate cow data • Interpretation of cow data complex in low prevalence farms • No risk of “false positive”
Simulating Johne’s control Kudahl AB, Ostergaard S, Sørensen JT, Nielsen SS. A stochastic model simulating paratuberculosis in a dairy herd. Prev Vet Med. 2007 Feb 16;78(2):97-117.
AJDI testing goals • Minimize false test results • Motivate farmers to take MANAGEMENT actions • Ongoing herd and cow testing project • Focus on low within herd prevalence herds • Dr. Carrie Lavers (PhD)
Herd-level testing Milk ELISA (2% cutoff) Sensitivity 55.7% Specificity 95.8% Environmental Culture Sensitivity 71.4% Specificity 98.6% (100%)
Atlantic Johne’s Disease Initiative Program Launch: June 2011 Enrolled 459 unique herds
EC Herd PrevalenceRound 1 EC Herd Prevalence
EC Herd PrevalenceRound 2 EC Herd Prevalence
Predicting Within Herd Prevalence (Lavers research) 6/6 positive 2/6 positive
Overall Prevalence • Total herds tested positive over 2 years = 118 • Cumulative prevalence = 25.7% • Identified 75% of those in year 1 and 25% only after second round • Very close to what would be predicted from Lavers research !
Benchmarking Atlantic Canada • USDA study 2006 • 68% of herds positive on single round • Alberta • 26% positive in first round • Higher rate in year 2 • Different collection procedures
Herd Management Plan • Maximum of 3 Best Management Practices • Rank recommendations in order of priority • Agreement between producer and vet
Why “Success” • Exceeded targets for participation • Highest of all voluntary programs • Hats off to program vets/industry steering group!!! • Education/extension success • One on one • Prevalence moderate • Lower than some regions (opportunity?) • 9% of herds have substantial problem • Can we build on this successful model?
Special Thanks • Collaborators • Drs Shawn McKenna, Marcelo Chaffer, Carrie Lavers, Emilie Laurin, Karen MacDonald Phillips • AJDI & MQM Staff • Art Gennis, Norman Wiebe, MariaVasquez, Natasha Robinson and Theresa Andrews • AJDI Steering Committee • Reint Jan Dykstra, Bloyce Thompson, Phillip Vroegh, Dr. Pauline Duivenrooden , Dr. Frank Schenkels, Richard Van Oord, Doug Thompson, Brian Cameron and Harry Burden
Check out this video bit.ly/HJhnjv Johne’s Disease in Canadian Dairy Herds -What is means to farmers By the U of Guelph MAP team – Steven Roche and Dave Kelton www.atlanticjohnes.ca