In the Czech republic, prevalence of paratuberculosis was increased since 1990, when clinically healthy animals were imported. Prevalence of paratuberculosis was studied in 101 beef cattle herd kept on pasture, and 95 dairy cows confined in stable. The objective of this study was to determine which risk factors influenced the likelihood of the herds to became infected and to compare the extent to which animals are infected in these two separate management practices and design a suitable control programme. Following very high positive serological survey and faecal culture, all animals were slaughtered. Tissue culture of 53 (52.5%) animals in beef herd and 52 (54.7%) animals in dairy herd were positive for paratuberculosis. Environmental samples (n=279) like faeces, wall scrapings, water, feed-leftovers, larvae and imagoes of dipterous flies in the barn and grass, soil and mud, pond water in the pasture were cultured, and 9.1 % and 2.0 % from the barn and pasture tested positive for Mycobacterium avium subsp. paratuberculosis, respectively. Prevalence of the disease in both herds was similar. Positive cows were compared against calves for the possible prenatal or neonatal infection of their daughters. Thirteen positive calves (68.4%) came from positive beef cows, whereas only 5 (17.2%) positive calves were born from positive dairy cows. This demonstrates the risk of direct mother-daughter infection on pasture and pooled milk feeding derived infection in dairy calves. The youngest calves with M. paratuberculosis infection were 7 months old. Similar rate of prevalence and identification of the same RFLP type in both herds demonstrate the absence of correlation between the breed type and susceptibility to paratuberculosis. For massive infection of both herds and contamination of the environment by M. paratuberculosis, a radical control programme was selected.
Supported by the grants No. QLRT - 2000 - 00879 (Brussels, EC) and QD1191 (Min. of Agriculture, Czech Republic).