For work package 1, which addressed drivers of Johne’s control on-farm, we used social science approaches. Building on a global systematic review of the literature on barriers and solutions for Johne’s disease control on-farm, we conducted an empirical study with over 400 farmers and 150 veterinarians across the UK. The study used workshops and semi-structured interviews to understand better the challenges farmers and veterinarians face in implementing on-farm Johne’s Disease with the aim of identifying solutions. In our systematic review of relevant literature from the last ten years, we identified five key barriers to Johne’s control: concerns with tests, the time taken to see results, a lack of space, a lack of interest in JD control, and economics.
The empirical study found that four main challenges are faced in the on-farm control of Johne’s – (1) Management of farmer expectations around Johne’s Disease with eradication near impossible, (2) A ‘free-riding’ problem which can be influenced by the partially voluntary nature of control plans, (3) Challenges in vet-farmer communication, including levels of knowledge,
(4) Space issues to segregate and the economics and practicality of changing infrastructure. Our findings have relevance for the control of Johne’s Disease in the UK and in other countries, including for regions with voluntary or compulsory control programmes.
Moving to work package 2, which focused on environmental sampling to test for Johne’s and the use of risk assessment, On environmental sampling, herds in Northern Ireland were selected with known or suspected Johne’s infection. An important barrier to using environmental sampling is how sensitive it might be – does it miss significant numbers of infected herds? Faecal samples were taken from 12 dairy farms. Samples were obtained from floor scrapings at 4 communal sites across 4 bi-monthly time points. MAP DNA (causative agent of Johne’s) was demonstrated on each of the farms on at least 1 time-point. The incidence on each farm (numbers of positive sites) differed across farms and across sample points within individual farms. The results of the study suggest that environmental sampling can determine the presence of MAP on farms with known MAP status, however multiple sampling is required, both spatially and temporally. While our study cannot determine sensitivity, it does act as quite strong proof of principle that environmental sampling could be a useful tool (if for example there was failure to detect it would be more doubtful).
As part of work package 2, we aimed to analyse the effectiveness of on-farm risk assessment for JD. The analyses will identify aspects of management that could predispose to the introduction and spread of infection within the farm and gain insights from the veterinarian recommendations. We are utilizing a dataset of herd risk assessments conducted by veterinarians and collected as part of the Northern Ireland Johne’s Disease Control Programme. Previously we worked with a smaller dataset but recently received additional data and are now working with a larger dataset to complete the required analyses. We expect to complete the analyses by the end of April 2024.