Egg Se concentrations of hens over the 84 d feeding period (mg/kg, wet weight basis). Blank control = a basal diet without Se supplementation, SS control = a basal diet plus 0.3 mg/kg of Se from sodium selenite, 0.1 mg/kg SY = a basal diet plus 0.1 mg/kg of Se from selenium-enriched yeast, 0.2 mg/kg SY = a basal diet plus 0.2 mg/kg of Se from selenium-enriched yeast, 0.3 mg/kg SY = a basal diet plus 0.3 mg/kg of Se from selenium-enriched yeast, 0.4 mg/kg SY = a basal diet plus 0.4 mg/kg of Se from selenium-enriched yeast. Columns with different superscripts (a, b, c, d, e) are significantly different at P < 0.05. Egg Se concentrations for each treatment data at the same collected day are means of 6 replicates of 4 samples each (3 eggs per sample). Abbreviations: Se, selenium; SS, sodium selenite; SY, Se-enriched yeast.