Occurrence of Isospora suis in larger piglet production units and on specialized piglet rearing farms

Mixed fecal samples of 264 litters from five piglet production farms (155-2 38 sows/farm) were investigated three times during the suckling period for the occurrence of Isospora suis over the period of 1 year. On all five farm s Isopora suis was found to be a common endoparasite with infection rates b eing highest in litters of 3-4 weeks of age, By the end of the third invest igation period the cumulative infection rate was 53.8% of the litters rangi ng from 20.0% to 81.5% for the single farms. During the suckling period the infection rate increased from 18.6% to 32.6% and then to 37.7%, Diarrhea w as present in 66.3% of the sampled litters with the highest rates at the en d of the suckling period. 63.4% of the litters which showed diarrhea and 34 .8% of those without diarrhea excreted I. suis within the study period. Dia rrhea was recorded for 78.2% of the I. suispositive litters and for 52.5% o f the Isospora-negative litters. In summer and fall the occurrence of I, su is was higher (66.3% and 61.0%, respectively) than in spring and winter (47 .7% and 37.9%, respectively). In litters with diarrhea and pathogenic E. co li I. suis often occurred simultaneously. Above-average hygiene measures an d mainly perforated pen floors seemed to lower the risk of isosporosis. Wit h the exception of Strongyloides ransomi other parasites were not found in the fecal samples of suckling piglets. Two specialized piglet rearing farms , a conventional large-scale rearing unit and a farm managed according to t he segregated early weaning (SEW) system were examined three times during t he 6-7 week rearing period. In both units I. suis was common, but was not c orrelated with diarrhea. In the SEW unit the infection rates decreased from 37.5% to 20.2% and to 4.1%, while the infection rate in the conventional u nit slightly increased from the first (17.2%) to the second (21.9%) investi gation and stayed at this level at the third sampling. (C) 1999 Elsevier Sc ience B.V. All rights reserved.