THE ASSOCIATION OF CATTLE HUSBANDRY PRACTICES, ENVIRONMENTAL-FACTORS AND FARMER CHARACTERISTICS WITH THE OCCURRENCE OF CHRONIC BOVINE TUBERCULOSIS IN DAIRY HERDS IN THE REPUBLIC-OF-IRELAND

A matched case-control study was undertaken to provide information pn the role of farm management practices, environmental factors and farme r characteristics in the epidemiology of bovine tuberculosis. Eighty d airy herds with chronic tuberculosis were compared with the same numbe r of herds which had been free of the disease for many years. A standa rdized questionnaire was used to obtain information from the farmers. The study was conducted from August to October 1990, in Counties Cork and Kilkenny, Republic of Ireland. Factors which were identified as po ssibly contributing to recurrent outbreaks of tuberculosis outbreaks i ncluded nutritional factors, cattle purchases (especially bulls), the presence of badgers, and the spreading of slurry. Overall, the finding s suggested that intensively managed dairy herds were at greater risk of bovine tuberculosis outbreaks than were other herds. The study did not support some of the hypotheses which traditionally have been put f orward as contributing to tuberculosis outbreaks. These included conta ct with neighboring cattle owing to movements to and from fragments or poor boundary fencing, presence of sub-standard cattle housing, movem ent of equipment or vehicles onto farms, and exposure to water supplie s from rivers or streams. In the light of these findings, and in view of the lack of evidence in the scientific literature to support these hypotheses, we suggest that a general re-evaluation of their role in c hronic tuberculosis is needed.