Effect of Animal Feed Enriched with Se and Clays on Hg Bioaccumulation in Chickens:  In Vivo Experimental Study

An in vivo experiment was conducted to evaluate the effects of sodium selenite, sepiolite, and bentonite on inorganic mercury (Hg) and methylmercury (MeHg) bioaccumulation. For this purpose 160 chickens were fed under different controlled conditions. Chickens were exposed to Hg(II) and MeHg added to feed with or without selenium or clays supplementation. No significant differences were observed in the voluntary intake and feed/gain conversion rates. The target organs of Hg(II) and MeHg in chickens were the liver and kidney, respectively, but the greatest body store was the muscle in both cases. A higher bioaccumulation for MeHg than for Hg(II) was observed. The results showed that addition of sodium selenite, sepiolite, or bentonite induced a decrease of up to 60−100% in the inorganic mercury bioabsorption. Bentonite addition to a MeHg-containing diet also caused a decrease in organic mercury bioaccumulation (29−67%). On the other hand, inorganic selenium and sepiolite did not decrease MeHg accumulation. Keywords: Selenium; mercury; bioaccumulation; chicken; animal feed; clays