Imidacloprid targets the humoral immune responses in chickens

The purpose of the current study was to investigate the immunological impacts of chronic imidacloprid insecticide toxicity in broiler chickens and the protective effects of vitamin E and selenium. Broiler chicks (n=90) aged day old were randomly segregated into three groups of 30 chicks each and were kept in separate pens. Newcastle disease (ND) vaccine was given on day 7 and 28 of age. On day 8, chicks in group I were administered 5 mg/kg bw (1/20 LD50) imidacloprid orally. Chicks in group II were given imidacloprid 5 mg/kg bw orally plus a mixture of vitamin E and selenium ≅ 200 mg/kg diet, while group III was given distilled water (DW) orally and served as a control. The treatments were given daily based on weekly body weight till day 45. Antibody titration, serum total immunoglobulins, circulating immune complexes, cell-mediated immunity and histopathology of bursa of Fabricius and spleen were examined. Imidacloprid produced significant decline in the titer of antibodies against ND vaccine, total immunoglobulins and circulating immune complexes in imidacloprid treated group on day 45 as compared to control group. There were no significant changes in the skin thickness between treated chickens and chickens of control group. Histopathology of the bursa of Fabricius revealed edema, lymphocytic depletion in the medulla and cortex and mild interfollicular fibrosis in imidacloprid treated group. The spleen showed mild haemorrhages and lymphocytic depletion.

Supplementation of vitamin E and selenium resulted in marked improvements in humoral immunity and pathology of lymphoid organs. It is concluded that imidacloprid insecticide has immunological deleterious effects in chickens targeting the humoral immune responses and vitamin E and selenium supplementation decreased the ill effects of imidacloprid.

Source:
Kammon et al., J Environ Anal Toxicol 2012, S:4 (attached)