Comparative effects of nano elemental selenium and sodium selenite on selenium retention in broiler chickens

Two experiments were performed to explore the selenium retention of Nano elemental selenium (Nano-Se) in Arbor Acre male broiler chickens as compared with sodium selenite. A 2×4 factorial arrangement with 0.15, 0.30, 0.60 and 1.20 mg/kg dietary Se from Nano-Se or sodium selenite added to a maize–soybean meal diet was conducted to study the effects of Se source and level on growth performance, serum glutathione peroxidase (GSH-Px) activity, Se concentration in serum and tissue. Furthermore, selenium retention of Nano-Se and selenite was determined in chicks by the oral or intravenous administration of the radiolabeled Se and the in vivo ligated intestinal loop procedure. As for selenite, average daily gain (ADG), gain/feed and survival ratio reached a plateau at the Se concentration of 0.15–0.30 mg/kg and then declined as supplemental selenite increased. As for Nano-Se, ADG, gain/feed and survival ratio reached a plateau at the Se concentration of 0.15–1.20 mg/kg. Survival ratio, ADG and gain/feed increased quadratically (P<0.05) as dietary selenite increased (P<0.05), and increased linearly and quadratically (P<0.05) as dietary Nano-Se increased (P<0.05). Selenium concentrations in serum, liver and breast muscle increased linearly and quadratically (P<0.05) as the dietary Se level increased for either Se source, but the magnitude of increase was substantially greater (P<0.05) when Nano-Se was fed. Retention of the orally or intravenously administered 75Se showed that the percentages of Nano-Se in the whole body and liver tissue were much higher (P<0.05) than those of selenite. Intestinal transport of 75Se from ligated loop to body showed that the transfer of Nano-Se from the intestinal lumen to the body was higher (P<0.05) than that of selenite, while the intestinal retention of Nano-Se was lower (P<0.05) than that of selenite. The results showed that the range between optimal and toxic dietary levels of Nano-Se was wider than that of sodium selenite, and Nano-Se was more efficiently retained in the body than sodium selenite.