In the feces of piglet 63, slaughtered at 12 h, no rotavirus could be detected. Moreover, only a small decrease in villus length (20%) was observed for this piglet and its 12-h replicate. To find additional evidence whether the jejunum of piglet 63 was effectively challenged with rotavirus, the level of IFN-c mRNA in jejunal mucosal scrapings was measured by real-time PCR (Fig. 1 ). In RNA samples isolated from the three uninfected pigs, hardly any IFN-c mRNA could be detected. In contrast, the IFN-c mRNA levels in scrapings of all infected piglets were up to 50-fold higher than in uninfected piglets, whereas OAZ1 mRNA levels were nearly equal for all RNA samples. This indicated that the jejunum of all piglets, including piglet 63, responded to the orally applied rotavirus challenge.