Fenvalerate induced cell mediated immunological alterations in chickens

Fenvalerate is a synthetic pyrethroid insecticide extensively used in various agricultural, animal husbandry and public health operations. It was considered quite safe but recent reports indicated the presence of residues in feed and food items and their harmful effects in man and animals. To assess the effect of fenvalerate on cell mediated immune response in chickens, a total of 60 chickens were used in two groups of 30 each. These birds were vaccinated with New Castle disease vaccine at day 4 and 12 week of age. Group I was kept as control while group II birds were given 20 ppm fenvalerate in feed daily for a period of six months. Lymphocyte stimulation test, total leucocyte count and absolute lymphocyte count were assessed at 10 days interval. A significant suppression in blastogenic capacity of T-lymphocytes was observed in fenvalerate fed birds as compared to controls. Besides, the total leucocyte count and absolute lymphocyte count reduced significantly in birds fed pesticide. The reduction in DTH reaction in pesticide fed birds also confirmed the suppression of CMI responses in fenvalerate fed birds.