Abstract
ABSTRACT:
The protective role of the probiotic Bactosac® in minimizing the negative oxidative stress and the biochemical and morphological alterations induced by sub-chronic exposure of broiler chicks to 2500 ppm lead (pb) acetate in drinking water for 5 consecutive weeks was evaluated. Results revealed that body weight in Pb acetate treated broiler chicks was significantly decreased (47 %). However, the co-administration of Bactosac® with Pb acetate succeeded to improve this percent to 19.62 % in comparison to control group. Also, antioxidants parameters of hepatic and renal tissues were significantly changed in Pb acetate exposed chicks, where the GSH concentration was significantly enhanced, while, GST and CAT activities, were significantly inhibited. Lipid peroxidation indicator MDA was also significantly increased. Activity of hepatic transaminases ALT and AST were significantly elevated in Pb acetate treated chicks while serum creatinine and blood urea showed no significant changes. The accumulation pattern of Pb in treated chicks revealed that the highest and significant concentration was recorded in bone (160 times), then kidneys (13 times), followed by Liver (2.2 times) and brain (1.6), while muscles showed the lowest (1.3 times) accumulation to Pb when compared to control values. Histopathological examination revealed presence of hepatocytic degeneration, necrosis and hemorrhages, as well as, vascular congestion of the inter tubular blood vessels, interstitial mononuclear cell infiltration, glomerular hypercellularity and some areas of inter tubular mononuclear cell infiltrations and aggregations in kidneys of pb-intoxicated birds. Concurrent treatment of Bactosac® with Pb acetate in drinking water of broiler chicks revealed a significant improvement of the previous antioxidant parameters, liver transaminases, accumulation pattern of Pb and morphological alterations. It is concluded that probiotics Bactosac® play an important and promising tool to prevent/reduce pb toxicity in broiler chicks.

Key words: protective effect, probiotic, lead toxicity, broiler chicks