[Epidemiologic studies of the course of reproductive events after epidemic late abortion (PRRS/PEARS) in swine breeding herds].

The evaluation of the reproductive performance in nine pig breeding herds that have been affected with PRRS in the beginning of 1991 is carried out by comparing data prior to, during and after the acute phase of PRRS. Piglet losses were increased during four month, performance data, such as percentage of return to oestrus and the interval between farrowings did not show substantial alterations from the pre-epidemic data. The evaluation of reproductive performance of gilts bought in the post-epidemic period did not reveal any depression. Sows which farrowed in the acute epidemic phase of the disease (even those with abortions) returned to their pre-epidemic level of reproductive performance in the following litter. A longlasting immunity due to the persistence of the PRRS virus in the region is discussed as cause for the return of the reproductive performance to the pre-epidemic level.