Citation: Lee, S.H., Lillehoj, H.S., Jeong, M., Xu, S., Kim, J.B., Park, H.J., Lillehoj, E.P., Bravo, D. 2014. Effect of in ovo injection with selenium on immune and antioxidant responses during experimental necrotic enteritis in broiler chickens. Poultry Science. 93(5):1113-21. doi: 10.3382/ps.2013-03770.
Technical Abstract: Selenium (Se) is an essential component of several major metabolic pathways in the antioxidant enzymes activity and modulating immune system. This study was conducted to investigate the effects of in ovo injection of selenium (Se) on modulating the immune system and antioxidant responses in chickens with experimental necrotic enteritis (NE). Broiler eggs were injected at 18 days of embryo age with either 100 µl of PBS alone or sodium selenite (Na2SeO3) in PBS, providing 0 (SS0 group), 10 (SS10 group), or 20 (SS20 group) µg Se/egg. At 14 days post-hatch, PBS-treated and uninfected chickens were kept as the control group while the remaining chickens were orally infected with 1.0 × 104 sporulated oocysts of Eimeria maxima (SS0, SS10, SS20). At 18 days post-hatch, E. maxima-infected chickens were orally infected with 1.0 x 109 colony forming units of Clostridium perfringens. Se-treated and co-infected birds in both the SS10 and SS20 groups had increased body weights, fewer intestinal lesions, reduced oocyst production, diminished serum malondialdehyde, catalase, and superoxide dismutase levels, and decreased intestinal glutathione peroxidase 7 mRNA levels compared with untreated and co-infected controls (SS0). SS10 and SS20 chickens also had higher levels of transcripts for interleukin (IL)-1ß, IL-6, IL-8, and inducible nitric oxide synthase expression in the intestine and increased antibody levels to C. perfringens a-toxin and NetB toxin in serum compared with the SS0 group. No significant differences were found in tissue Se levels among any of the treatment groups. These collective results suggest that injection of Se into the yolk of incubating eggs may be beneficial for enhancing immune and antioxidant responses to necrotic enteritis in broiler chickens.