Morphological changes in the internal organs of laying hens during chronic poisoning with the neonicotinoid “Aktara 25 WG”

Neonicotinoids are a new class of synthetic insecticides developed based on nicotine's structure to protect many crops from harmful insects. The article presents the results of studies of morphological changes in the organs of laying hens during chronic experimental poisoning with a neonicotinoid - Aktara 25 WG. Chronic poisoning with Aktara 25 WG was reproduced by feeding compound feed treated with this drug in doses calculated in mg of active ingredient per 1 kg of body weight. The birds of the first group served as controls and received compound feed without additives. Chickens of the first experimental group were fed compound feed containing the drug Aktara 25 WG at a dose of 360 mg/kg b.w., and chickens of the second experimental group consumed compound feed containing 180 mg/kg b.w. of the drug Aktara 25 WG. It was found that feeding laying hens with feed containing Aktara 25 WG in different doses for 30 days leads to an increase in the spleen mass coefficient, a decrease in the heart and liver mass coefficients. Feeding feed with Aktara 25 WG caused a reduction in the relative mass coefficient of the liver and the muscular part of the stomach in laying hens of the experimental groups, the results of which significantly correlate with the absolute mass indicators of the corresponding organs and are direct evidence of the toxic effect of the insecticide “Aktara 25 WG” on the animal body, where the digestive organs react first of all. In the chickens of the first experimental group, dystrophic-necrobiotic changes are observed in the liver, round-cell infiltration of the portal tracts; in the kidneys – dystrophic-necrobiotic changes in the epithelial cells of the renal tubules; in the myocardium – granular dystrophy of cardiomyocytes, capillary hyperemia, stasis and edema of the stroma; in the brain – pericellular edema; in the stomach – mucous dystrophy, desquamation of the mucosal epithelium, decrease in lymphocytes in lymphoid structures, atrophy of the epithelium of glandular structures; in the small intestine – hyperemia and necrosis of the apical part of the villi, round cell infiltration in the crypt area; in the colon – proliferation of cellular elements of the connective tissue between the crypts.