Asiya N. Khan
Abstract: Effects of in-ovo intoxication of an insecticide formulation Nurelle D 505 EC (chlorpyrifos 50 % EC + cypermethrin 5 % EC) was evaluated in two generations of domestic chick. The investigation covered four groups of fertilized RIR eggs – three for experimental and one for control. Experimental groups of eggs received doses of 0.01, 0.05 and 0.1 μg/egg of combination insecticide (Ci) and the control received corn oil on day zero of incubation. The doses were selected based on our previous study. The eggs were incubated and upon hatching the F1 generation chicks were sorted as per their treatment, tagged and reared on standard diet. Upon sexual maturity the birds from the same groups were allowed pen mating. The fertilized eggs were collected and incubated for the next generation (F2). The eggs were regularly candled every two days till the 18th day of incubation to cull out the unfertile or dead embryos. The dead embryos and hatchlings were given a meticulous visual examination and the rate of morphological malformations was calculated. The study showed that chlorpyrifos and cypermethrin applied in a mixture caused significant increase in the rate of mortalities and decreased hatchability in chick of F1 and F2 generation. The morphological abnormalities caused by the treatment of the Ci were also observed in chicks of F1 & F2 generation. This is the first report of Ci induced structural anomalies in the second generation of chicks and we believe that the test system can evolve as an alternate model for testing two generation developmental toxicity.
Keywords: Chlorpyrifos, Cypermethrin, structural anomalies, Fertilized RIR Eggs