Assessment of toxicological effects and persistence of the fungicide Zineb in laying hens

ABSTRACT

Zineb, a fungicide of ethylenebisdithiocarbamate group, is widely used as a protective fungicide in agriculture purposes. The present work was carried out to assessment the toxicological effects and the fate of "zineb" in laying hens. Zineb and some of its degradation products have been prepared in our laboratory for the present investigation. Hens were treated with 50 and 100 ppm of zineb in the feed for two months followed by one month recovery period. At the end of the experimental period, both plasma and red blood cells [RBCs] - cholinesterase activities showed a moderate inhibition amounting to [24.4 and 31.0% for plasma and 8.0 and 10.5% for RBCs at two treated doses [50 and 100 ppm], respectively. Liver and kidney functions as well as lipid profile of the treated hens were increased, while concentration of total protein and albumin were decreased during the experimental period. All the blood parameters returned to control values after a one month recovery period except lipid parameters [Cholesterol and triglycerides]. The residual analysis of the extracts of whole eggs, blood and different organs of laying hens revealed that, a considerable amount of the parent compound was detected and amounted to, whole eggs [0.171 and 0.322 ppm], fat [0.071 and 0.135 ppm], liver [1.11 and 2.05 ppm], muscles [0.385 and 0.650 ppm], whole blood [0.160 and 0.305 ppm] and heart [0.155 and 0.270 ppm] for both doses [50 and 100 ppm], respectively at the end the experimental period. Chromatographic analysis by TLC and HPLC of the extracts of whole eggs, blood and different organs of laying hens showed the presence of five degradation products in addition to the parent compound zineb