Detection of enzootic pneumonia in pig herds using an enzyme-linked immunosorbent assay in sow colostrum

A total of 6256 colostrum samples from 185 Finnish pig health scheme herds were screened for Mycoplasma hyopneumoniae antibodies, using a commercial ELISA kit, between November 1989 and April 1991. Most (162) of the herds were negative. In six herds, in which positive colostrum samples were found, the presence of enzootic pneumonia was confirmed by clinical and pathological findings. One herd had several seropositive sows but no clinical disease and in 16 herds occasional positive colostrum samples were found. Antibodies appeared in the colostrum four days to six months before the signs of the clinical disease; the number of seropositive sows was low (average 10.6 per cent). The specificity of the ELISA was estimated to be as high as 99.4 per cent in this study. Colostrum appeared to be a suitable sample for ELISAS.