Effects of Organic Selenium on Laying Performance, Selenium Absorption and Utilization, Antioxidant Activity and Immunity in Laying Hens

To study on influences of organic selenium on laying performance, Se absorption and utilization, immunity and antioxidant activity, 400（laying rates 85%）hens during the period of 43-week were randomly allocated to 1 of 4 homogeneous treatments： (control treatment，no added Se feed; Na selenite, 0.3 mg Se/kg; yeast selenium, 0.3 mg Se/kg and DL-methionine selenium 0.3 mg Se/kg). Every treatment had 10 replicates, every replicate had 5 hencoops and every hencoop had 2 hens. We hypothesized that organic selenium was better than inorganic selenium, and DL-selenium had advantages over them of yeast selenium in some ways for laying hens. The experiment lasted for 77 d, with the first 7 d for adaptation. Egg production, laying rates and dry matter intake were recorded every day. And Se contents of serum, whole eggs, heart and liver, blood antioxidant and immunity index were analyzed in the 78th d of the study. The results showed Se sources had no significant effects on laying performance and eggs qualities （ P ＞ 0.05 ）, except for the groups of organic selenium increased egg mass or had trends of increasing laying rates compared with the groups of control and inorganic selenium in the tenth week significantly respectively（P﹤0.05 or P=0.07, P=0.06 and P=0.08）. The groups of organic selenium had increased the contents of Se in serum, whole eggs, heart and liver very significantly（P﹤0.01）；and increased glutathione peroxidase activity and antioxidant capacity significantly（P﹤0.05）. At same time, the groups of organic selenium had increased significantly or had trends to increase the immunoglobulin G in serum（P ﹤0.05 or P=0.05）. In a word, adding organic selenium in diets could improve laying performance, strengthen Se absorption and utilizations, antioxidant capacity and immunity of laying hens to the extent in a longer experiment. And the effects of DL-selenium had advantages over them of yeast selenium in some ways. It implicated that DL-selenium was benefited to production of laying hens and selenium-enriched eggs. Key words： Selenium；Laying performance; Absorption and utilization；Antioxidant activity; Immunity Summary text: Selenium is an essential mineral not only for animal nutrition, but also for humans’ nutrition. Organic selenium had more advantages in improvement of laying performance, Se absorption and utilizations, antioxidant capacity and immunity of laying hens. Especially, DL-selenium was a valuable product, which was benefits to improve production of laying hens and develop functional food, selenium-enriched eggs.