Control of Mycobacterium avium subsp. paratuberculosis infection on a New Zealand pastoral dairy farm

Keeping the ‘R’ in DRL – the latest peer-reviewed and published study from DRL, carried out in collaboration with Dr Andrew Bates of Vetlife New Zealand and the Centre for Dairy Excellence, describes the control of Johne’s disease on a large NZ pastoral dairy farm using DRL’s testing strategy and the results really speak for themselves.

At the beginning of this four year case study of a large dairy farm with a history of Johne’s disease (JD), 5% of calved cows were being culled annually with suspected clinical JD (55/1,201) falling to 0.4 % (5/1,283) in the final year of the control program. Similarly, at the start of the study 26% of cows were serum test positive, falling to just 3% after three years of intervention. By implementing a smarter testing approach in which the highest MAP shedders were earmarked for earliest removal, the infectious pressure on the remainder of the herd was quickly reduced. After the first year of intervention, farm production increased by 27,294 KgMS, from 53 fewer cows. In addition, the early identification of subclinically infected cows allowed for full carcass recovery of cull cows which alone negated testing costs.