However, similar to our findings, Adel-Patient et al. found no specific anti-Cry1Ab antibody BYL719 response in serum from mice fed MON810 maize following intragastric or intraperitoneal sensitization. On day 100, pigs fed the Bt/isogenic maize diet tended to have a higher leukocyte count than those fed either Bt or isogenic maize for 110 days. This increase was primarily a reflection of the increase in lymphocyte count in these pigs. Both leukocyte and lymphocyte counts for all pigs fed Bt maize at some point during the study were above the normal reference range for pigs. The immunophenotyping data indicated that T cell populations were not influenced by feeding Bt maize; however, B cells were not evaluated. While lymphocyte counts were elevated significantly in some pigs fed Bt maize, there was no indication of a Th 2- mediated allergic inflammatory response to the Cry1Ab toxin in the form of antigen-specific Ig production. The spleen weight of these pigs, reported previously by Buzoianu et al., did not differ between treatments and no histopathological indicators of organ damage were evident in the spleen or other organs. Likewise, the cecal bacterial community structure was similar across treatments and as a result alterations in immune response as a consequence of changes in gut microbiota were not anticipated. A study using rats as an animal model for the safety evaluation of Bt rice found that leukocyte count and MCH were decreased in male rats; however, all haematological parameters analyzed were within the reference range for rats of the age and breed used. Krzyzowska et al. also found that leukocyte counts were increased when mice were fed GM triticale, but again, these values were within the normal reference range for mice. Erythrocyte counts in pigs fed Bt maize for 80 days or longer were lower than in pigs fed the Bt/isogenic maize diet. We have previously reported a SP600125 decrease in erythrocyte counts in sows fed Bt maize. However, in that study haemogloblin concentration and hematocrit were also decreased and the changes observed were not attributed to Bt maize consumption. In an earlier study with weanling pigs, we detected a small fragment of the cry1Ab gene in the gastric digesta of all pigs fed Bt maize; however, detection in the ileal and cecal digesta was limited to two and one pigs, respectively while the gene fragment was undetectable in the colon. However, in the present study, in older pigs cry1Ab gene fragments were detectable in the gastric digesta and the 211 bp gene fragment only was detected at low frequency in ileal digesta. The cry1Ab gene, regardless of amplicon size, was not detected in the cecum or colon. Nucleic acids are known to endure extensive enzymatic degradation in the GIT. Potentially, the transgenic DNA was degraded by microbial DNAse enzymes which are most likely present at higher concentrations in the cecum and colon as a result of larger microbial populations.