Effect of Bt cotton plants on oxidative stress in sheep

Abstract

Sheep (32) of 1–year age belonging to Deccani breed were randomly divided into 4 groups consisting of 8 sheep in each group. Group 1 was maintained on basal diet (green fodder @ 3 kg + concentrate feed @ 300 gm/sheep/day) and 2 on conventional (non-Bt) cotton plants @1.5 kg + green fodder @1.5 kg + concentrate feed @ 300 g/sheep/day, 3 on Bt cotton plants @1.5 kg + green fodder @1.5 kg + concentrate feed @ 300 g/sheep/day and 4 on Bt cotton plants ad lib. + concentrate feed @ 300 g/sheep/day. All the groups were fed for 3 months. Parameters related to oxidative stress in organs of all groups and the concentration of gossypol in sera samples of groups 2, 3 and 4, and Bt (Cry1Ac) protein in rumen liquor in groups 3 and 4 were evaluated at the end of third month of feeding, while the concentration of Bt (Cry1Ac) protein in sera samples of groups 3 and 4 was quantified at monthly intervals for 3 months. The mean concentration of GSH and TBARS, and the activity of SOD and catalase in liver, kidney and heart showed statistically nonsignificant difference among the groups. The Bt (Cry1Ac) protein was not detectable in sera samples of groups 3 and 4 at different time intervals, while rumen liquor had detectable concentrations at the end of third month of feeding. Gossypol was not found in the sera samples of sheep fed on Bt and non-Bt cotton plants. In conclusion, the study revealed that feeding of Bt cotton plants did not induce oxidative stress in sheep and sera samples were negative for Cry1 Ac protein and gossypol.