A study of thirteen years of a beef breed society's Johne's disease control initiative

The progress of the Welsh Black Breed Society's Johne's disease control initiative over a 13 year period was studied. Forty-four per cent of 323 herds that underwent three annual herd tests showed evidence of infection and 56% were classified as free of infection. From a subset of 108 herds, representing all those that started testing between 2000 and 2003, 89 (82%) had obtained three consecutive negative annual herd tests to achieve Johne's disease free status, by the end of 2012. Eleven herds subsequently failed to maintain disease free status leaving 78 herds (72%) with disease free status at the end of 2012. The main factors that appeared to influence the time taken to gain freedom from Johne's disease were the initial level of infection and herd size. Through the study period on average 3-4% of herds lost their Johne's free status each year. The steady increase in the proportion of cattle entered into the pedigree sales from Johne's free herds was considered to be of value to the breed society in reducing disease spread from herd to herd. For the year 2012, 95% of cattle entered into pedigree sales were from herds that were accredited as Johne's disease free with the CHeCs accreditation programmes. In 2010, the most recent year where the number of herds that registered cattle with the breed society was available there were 214 (62%) of a possible 344 herds participating in the control initiative.