Crop Biotech Update

Effects of Bt Maize Feeds on Immune Response and Digestive Fate of Bt Gene and Protein

May 11, 2012

A study was conducted to evaluate the long-term and age-specific effects of feeding Bt maize on the immune response of pigs and to know the fate of cry1Ab gene and protein. This study was conducted by Peadar Lawlor of Teagasc, Ireland, and other scientists and was published in PLos One open-access journal.

Forty day old pigs were fed with different treatments: non-Bt maize  (isogenic) diet for 110 days; Bt maize-based diet for 110 days (Bt); non-Bt maize diet for 30 days and Bt maize-based diet for 80 days (isogenic/Bt); and Bt maize-based diet for 30 days and non-Bt maize diet for 80 days (Bt/isogenic). Blood samples of the pigs were taken at different times during the study for haematological analysis, measurement of cytokine and Cry1Ab-specific antibody production, immune cell phenotyping, and detection of cry1Ab gene and protein. After 110 days, the pigs were sacrificed for analysis of stomach contents and organ samples.

The findings revealed differences in the counts of white blood cells and red blood cells of pigs under different treatments. However, these immune responses were not age-specific and were not indicative of allergic or inflammatory responses due to Bt maize. No evidence was found for translocation of Bt gene or protein to organs or blood.

Read the open-access article at