How safe is the use of chlorpyrifos: Revelations through its effect on layer birds

AIM The present study was aimed to investigate the immunological competence of chlorpyrifos (CPF) insecticide after oral administration in layer chickens. MATERIALS AND METHODS A total of 20 White Leghorn birds were given CPF in drinking water at 0.3 ppm/bird/day (no observable effect level dose) for a period of 3-month. Immune competence status of layer birds and chicks hatched from CPF-treated birds were estimated at 15 days interval in layer birds and monthly interval in chicks using immunological and biochemical parameters. RESULTS There was a significant decrease in values of total leukocytes count, absolute lymphocyte count, absolute heterophil count, total serum protein, serum albumin, serum globulin, and serum gamma globulin in the birds treated with CPF as compared to control. Similarly, immune competence tests such as lymphocyte stimulation test, oxidative burst assay, and enzyme-linked immunosorbent assay tests indicated lower immunity in birds treated with CPF as compared to control. Subsequently, chicks produced from CPF-treated birds were also examined for immune competence, but no significant difference was observed between chicks of both the groups. CONCLUSION The exposure to CPF produced hemo-biochemical and other changes that could be correlated with changes in the immunological profile of layer chickens suggesting total stoppage of using CPF in poultry sheds.