Fly control and chronic toxicity from feeding two chlorinated organophosphorus insecticides to laying hens.

Abstract

The effects of administering technical SD-8211 (2-chloro-1-(2,5-dichlorophenyl) vinyl dimethlyl phosphate) and SD-8280 (2-chloro-1-(2,4-dichlorophenyl) vinyl dimethyl phosphate) at concentrations of 50, 200, and 800 ppm in the feed of laying hens for 1 year were studied. The mean daily intake of actual insecticide per hen was estimated as 5.2, 20.4, and 84.2 mg for those receiving 50, 200, and 800 ppm of SD-821, respectively, and 5.3, 20.8, and 80.3 mg for those receiving 50, 200, and 800 ppm SD 8280, repectively. More effective fly control was obtained in droppings from SD-8280-treated hens than from SD8211-treated hens. Levels as low as 50 ppm resulted in moderate control of the house fly. Musca domestica L, and a flesh fly, Boettcherisca peregrina (Robineau-Desvoidy), but at least 200 ppm were required for good control of these species and moderate control of an anthomyid, Fannia pusio (Wiedemann); a blow fly, Chrysomya megacephala (F.); and a flesh fly, Parasarcophaga argyrostoma (Robineau-Desvoidy). No hen mortality occurred that could be attributed to insecticidal treatment, but there was an inhibiting effect on blood plasma cholinesterase activity related to insecticidal concentration. Egg production was slightly lower in hens fed 800 ppm SD-8280 than in the control hens. However, overall feed consumption, body weight, feed efficiency, egg weight, interior egg quality, shell thickness, egg flavor, and egg odor were normal in all treated hens.