A total of 300 one-day-old broilers were randomly assigned to six dietary treatments in a 3 by 2 factorial treatment arrangement to evaluate the effects of sodium selenite (SS), selenium yeast (SeY), and selenized glucose (SeGlu) supplements, as well as their combination with probiotic, on broiler growth performance, histomorphology, microbial population of the intestine, and immune response. Among the factors investigated were selenium sources (0.3 mg/kg) and probiotic levels (0 and 100 mg/kg of diet). The treatments were tested on five floor pens with ten birds each. Over the entire period, broilers fed SeGlu had a higher body weight gain and a lower feed conversion ratio than broilers fed SeY or SS (P<0.05). Interaction results showed that broilers fed SeGlu plus probiotic had higher lactic acid bacteria counts and lactic acid bacteria/coliform ratios in the ileum than those fed SeY without probiotic (P<0.05). Furthermore, when compared to SS alone, broilers fed SeGlu plus probiotic had greater villus height, villi height to crypt depth ratio, villus surface area, and goblet cell density (P<0.05). Broilers fed diets containing supplemental SeGlu had higher total anti-sheep red blood cells (SRBC) titre, IgG, and IgM titers than SeY and SS (P<0.05). Furthermore, broilers fed SeGlu plus probiotic dietary supplementation had higher IgG at 42 d. As a result, it could be argued that SeGlu, as a novel and simple Se source plus probiotic, is more effective than SS and SeY in improving broiler performance, microbial population, intestinal morphology, and immune response. تفاصيل المقالة