Strategy for restocking of Moorepark after depopulation following bovine spongiform encephalopathy

A strategy was formulated for restocking of the Moorepark herd after depopulation following bovine spongiform encephalopathy (BSE). The strategy document included the requirements in relation to the health status of the herds from which animals would be purchased (source herds) and those for individual animals in terms of genotype, pregnancy status and health status. Suitable animals were located in 17 herds; blood samples were taken from 437 pregnant heifers in those herds amongst which 75 (17 per cent) animals were positive for Mycoplasma bovis, 74 (17 per cent) were positive for infectious bovine rhinotracheitis (IBR), and 244 (56 per cent) were positive for bovine viral diarrhoea (BVD). Animals were purchased from 12 herds: 297 pregnant heifers from 10 herds and 105 weanling heifers from five herds, of which three had provided pregnant heifers. After purchase, procedures were put in place to minimise the risk of disease. This included treatment with appropriate antibiotics, anthelmintics and vaccination for leptospirosis and IBR when the animals arrived on the Centre. In addition, animals were segregated into 11 groups on arrival at the Centre and were inspected four times daily, particularly for signs of imminent abortion. Animals calved in isolation, and weekly calving groups were maintained together until all in the group tested clear for brucellosis. A blood testing schedule included monthly sampling for brucellosis until the calving season was completed. Abortions (three) and stillbirths (31) were retrieved and investigated to establish cause, where possible. In all, 7,222 tests were performed during the first year after the animals had been purchased (1998). Herd health status has been maintained to date (December 2000).