A comparison between intubation and food addition as routes of oral exposure for northern bobwhites to DDT insecticide.

Our objective was to compare two methods of oral dosing of p,p'-DDT (1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane) on uptake of DDT metabolites and isomers (i.e., p,p'-DDT, o,p'-DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD, o,p'-DDD) in livers and brains. p,p'-DDT was administered to northern bobwhite (Colinus virginianus) by intubation with corn oil or as a feed additive for 56 days. When adjusted for amount of DDT consumed, total DDT (sigma DDT, the summation of all DDT metabolites and isomers) and p,p'-DDE concentrations differed significantly (P less than 0.10) in both brains and livers, whereas p,p'-DDD differed only in brains and p,p'-DDT differed only in livers. Paired comparisons between brains and livers differed significantly for sigma DDT, (P less than 0.05), p,p'-DDE (P less than 0.05) and p,p'-DDT (P less than 0.1) for both intubated and food-dosed treatment groups, whereas p,p'-DDD (P less than 0.05) differed only in the intubated group. We concluded that method of oral exposure affected the uptake of DDT in livers and brains for northern bobwhites.