Effects of organic selenium supplementation on growth performance, nutrient utilisation, oxidative stress and selenium tissue concentrations in broiler chickens

The effects of organic selenium (Se) supplementation of diets for broiler chickens were evaluated in the present study. Broiler diets had average background Se concentrations of 0.36 mg/kg Se (control diet) and were supplemented with two organic Se sources, namely BiOnyc (R) Tor-Sel (selenohomolanthionine = SH) and Alltech's Sel PlexTM (selenomethionine = SM); their addition increased dietary selenium concentrations by an average of 0.57 mg/kg Se. Their effects on growth performance, nutrient utilisation and oxidative status of broiler chickens were determined. Growth performance was very similar across all dietary treatments; in contrast, significant differences in nutrient utilisation were observed. The N-corrected apparent metabolisable energy value for the control group (14.14 MJ/kg) and SH (14.15 MJ/kg) diet was significantly (P < 0.01) higher than that for the SM (13.64 MJ/kg) diet. Alternatively, N retention with the SM (68.4%) diet was significantly (P < 0.005) higher than that for the control (65.2%) and SH (64.5%) diets. Neither of the Se sources influenced plasma concentrations of reactive oxygen metabolites, biological antioxidant potential and advanced oxidation protein products. The activity of glutathione peroxidase, superoxide dismutase in both plasma and tissues samples and the concentration of plasma glutathione were increased by SH and SM compared with the control group. Our findings suggest that SH and SM improved the antioxidant status of broilers by elevating activities of antioxidant enzymes and concentrations of antioxidant. Both Se supplements significantly (P < 0.001) increased Se concentrations in liver and muscle, and in liver tissue there was no statistical difference between the two supplements. However, SH generated significantly higher Se concentrations in muscle tissue (0.283 versus 0.257; P < 0.005) than did SM. In summary, SH was at least the equivalent to SM as a source of organic Se for broiler chickens under the conditions of the present feeding study. This is reflected in the outcome that SH generated significantly higher Se concentrations in muscle tissue than did the alternative Se supplement.