Development of a HACCP-based approach to control paratuberculosis in infected Irish dairy herds

Paratuberculosis is a challenging disease to control at farm level, in part due to the poor sensitivity of diagnostic tests and a prolonged incubation period. Simulation studies have highlighted on-farm management to be the most important factor in preventing on-farm spread. A risk assessment (RA) and management plan (MP) approach (collectively, RAMP) has been adopted around the world as the most appropriate method of controlling disease in infected farms. However, there are problems with RAMP that remain to be resolved. The RA relies heavily on farmer recollection and estimation resulting in subjectivity and substantial inter-observer variability. MPs consist of a series of qualitative, farm specific recommendations showing how management can be improved. However, MP assessment is generally conducted informally, and progress is monitored through 'end-point' diagnostic testing of adult animals and repeated risk assessments. Hazard analysis and critical control point (HACCP) has been developed as a proactive alternative to end-point testing. We hypothesise that farm-based HACCP systems may be a useful alternative to RAMP on farms where more intensive monitoring and evaluation of controls for paratuberculosis is required. Therefore, the objective of this methodological study was to develop a HACCP-based system for paratuberculosis control. Critical control points (CCPs) relating to peri-parturient area management, calving, new-born calf management and colostrum management were identified as areas where additional control could be exerted above existing methods. Novel monitoring systems were developed for each CCP, along with targets and corrective actions. This system is intended for use in high prevalence herds, or farms where more robust monitoring of key control points may be beneficial. It is currently being trialled on infected commercial dairy herds in Ireland.