Effect of Bentonite on Supplemental Zinc Uptake and Distribution in Rats

Rats were offered ad libitum zinc in twice the level of the standard diet (23 mg/kg diet), and bentonite (2% additive) for 28 d, together with traces of zinc chloride (labelled with zinc-65) given intragastrically. Results provided evidence that bentonite increased the body retention of zinc in comparison to the diet without this agent. Furthermore, the addition of bentonite did not influence feed intake, organ to body ratios, and haematological values, although a visible decrease in body weight gains following bentonite feeding was noted. These findings may be useful when bentonite fertilised diet is provided to animals pastured in areas with higher zinc levels.