Abstract
Background: Chromium (Cr), a naturally occurring heavy metal, exists in many states, but the trivalent Cr (III) and hexavalent Cr (VI) forms are the most common in the environment. Acute and chronic toxicity in both animal and man are mainly caused by Cr (VI) compounds. Studies on hematological parameters in sub-acute toxicity of potassium chromate in broiler chicks are limited.

Aims & Objective: The study was envisaged to evaluate the protective effect of vitamin E and Selenium on haematological parameters in sub-acute oral toxicity of potassium chromate [Cr (VI)] in broiler chicks.

Materials and Methods: Potassium chromate (K2CrO4) used as test compound and Vitamin E and Se powder as Tocosel® contained 5 g of Tocopherol acetate and 30 mg of sodium selenite per 10 gm. LD50 was calculated before initiating the experiment by graphical probit analysis method. Experiment was conducted in randomly divided four equal groups (n=6) of day old chicks. Chicks of each group were maintained up to the age of 45 day and sacrificed on 46th day. Chicks of control group (T1) were provided only with basal diet and drinking water. While groups T2 and T3 was fed different concentrations of K2CrO4 and T4 as treatment group supplemented with Vitamin E and Se.

Results: LD50 of K2CrO4 in broiler chick was calculated as 277.95 mg/kg. Feeding potassium chromate [Cr (VI)] in group T2 (1/5th of LD50) and T3 (1/3rd of LD50) for 30 days, decreased haemoglobin percentage, haematocrit values, total erythrocyte count and total leucocyte count while increased the clotting time in a dose dependent manner. In group T4 chicks fed 1/3rd of LD50 of K2CrO4 and simultaneous treatment of Vitamin E and Se, normalised these haematological values, signifying its protective effect in sub-acute hexavalent chromium toxicity produced by potassium chromate.

Conclusion: It may be concluded that above mentioned changes might have reduced erythrocyte number, leucocyte number, haemoglobin value and increased clotting time. Vitamin E and Se containing glutathione peroxidase are among the principle in vivo chain breaking antioxidants, thus had protective effect.