Effects of organic, inorganic, and nano-Se on growth performance, antioxidant capacity, cellular and humoral immune responses in broiler chickens exposed to oxidative stress

• Tert-BHP induced oxidative stress in broiler chickens.
• Selenium supplementation improved immune system and antioxidant status.
• Nano-Selenium reduced oxidative damage in oxidation condition.
• Nano-Selenium had greater effects compared to inorganic and organic Selenium.
• Different Selenium sources reduced serum concentration of malondialdehyde.

The present study was designed to compare different sources of Selenium (Se) on growth performance, antioxidant capacity, cellular and humoral immune responses of male broilers subjected to oxidative stress. In a completely randomized design, 320 broilers were assigned to a 2×4 factorial arrangement comprising 4 replicates of 10 birds per each. Broilers were divided in two groups for oxidative stress; a group as control (no oxidative stress) and the other one was peritoneally received tert-butyl hydro peroxide (tert-BHP) as oxidative stress inducer. Birds in each level of oxidative stress were received either supplemented Se diet (CON) or diets supplemented with 0.3 mg/kg nano-Se (NAN), organic Se (ORG), and inorganic Se (INO). Sources of Se, oxidative stress, and their interaction had no effect on the feed intake, daily body gain and feed conversion ratio (P>0.05). Se supplementation increased glutathione (GSH) content and glutathione peroxidase (GSH-Px) activity compared to the control group (P<0.05). However, birds in oxidative stress had lower glutathione (GSH) content and GSH-Px activity as compared to non-stressed ones. Se supplemented groups had lower malondialdehyde (MDA) concentrations compared to the control groups (P<0.05), and birds on oxidative stress conditions had higher MDA level as compared to non-stressed birds. The IgM and IgG levels were significantly increased in NAN group compared to CON and other experimental groups (P<0.05). The highest serum IgG and IgM concentrations were recorded for non-stressed birds received nano-selenium and organic selenium. Birds in oxidative groups had lower foot swelling response value as compared to non-oxidative groups only at 24 h following the phytohemagglutinin-P (PHA-P) injection (P<0.05). The oxidative condition decreased the lymphoid organs weight compared to non-oxidative condition. These increases in antioxidant enzyme activities have been considered as a protective response against oxidative stress. It was concluded that supplementation of diet with 0.30 mg/kg of different sources of Se increased the antioxidative capacity of broiler chicken under oxidative stress and nano-Se effect was higher than organic or inorganic source.