Study on the Effects of Cytokine Level in Ducklings with Selenium Poisoning

One-day-old healthy ducklings (n=100) were randomly allocated into two groups (n=50, respectively) to investigate the effect of cytokines on ducklings with selenium poisoning. The ducklings in control group (Group I) were fed with full rations containing 0.3 mg kg−1 selenium, and the ducklings in selenium poisoning group (Group II) were fed with seleniumexcessive rations containing 8.0 mg kg−1 selenium. One mL blood was collected by cardiac puncture at d 15, 30, 60, and 90 (n=10, respectively), serum was separated by centrifugation. Contents of cytokines were determined by the radioimmunity method (RIA). The results showed that the contents of IL-1β, IL-2β in Group II were higher than that in control group at d 15 (P>0.05), but were significantly lower at d 30, 60, and 90 (P<0.01); the contents of IL-8β5 in Group II were significantly lower than that in control group (P<0.01); the contents of erythropoietin (EPO) and IGF-2 in Group II were significantly lower in different degree than that in control group at d 60 and 90 (P<0.01); the contents of granulocytemacrophage colony stimulating factor (GM-CSF) in the two groups were lower in different degree and significantly lower at d 60 and 90 (P<0.01). It can be concluded that the excessive selenium could result in a decrease in immunity and a series of clinical pathology changes, such as anemia, tissue hemorrhage, and necrosis.