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. https://macorners.shop/product-category/metal-garden-stake/