中文摘要：

为比较研究富硒益生菌（selenium-enriched probiotics,SP）和亚硒酸钠（sodium selenite,SS）对鸡产蛋性能和肝脏Ⅰ型脱碘酶（IDⅠ）活性以及血清T3和T4水平的影响,将2种硒源分别以0.2、0.5和1.0 mg.kg-1 3个硒水平添加到基础日粮中组成6种试验日粮,同时将益生菌添加到基础日粮中作为益生菌对照,基础日粮作为空白对照。选取800羽健康罗曼蛋鸡,随机均分为8组,进行为期35 d的饲养试验。在试验期间记录产蛋性能,在试验的第28天,取静脉血和肝脏测定血清T3和T4水平以及肝脏IDⅠ活性。结果表明：富硒益生菌对鸡产蛋性能有显著影响,硒源和硒水平对蛋鸡肝脏IDⅠ酶活性以及血清T3和T4水平均有极显著影响。添加SP或益生菌均可提高蛋鸡产蛋率、日产蛋量和平均蛋质量,降低料蛋比;添加SP或SS均能提高蛋鸡肝脏IDⅠ酶活性和血清T3水平,降低T4水平,特别是添加SP时,随着硒添加水平的升高,蛋鸡肝脏IDⅠ酶活性和血清T3水平升高,血清T4水平则降低;而添加益生菌对蛋鸡肝脏IDⅠ酶活性没有显著影响,却能显著提高血清T3水平,而降低T4水平。结论：添加SP的效果优于添加SS或益生菌。

英文摘要：

This experiment was conducted to compare the effects of selenium-enriched probiotics（SP）and sodium selenite（SS）two sources on laying-egg performance,the typeⅠiodothyronine（IDⅠ）activity and the level of T3 and T4 in hen serum.Both selenium（Se）sources were added into basal diet at 0.2,0.5 and 1.0 mg·kg-1 of Se to make six kind experiment diets.At the same time,probiotics was added into basal diet to make the probiotics control,and basal diet served as the blank control.Eight hundred healthy Rohman laying hens were randomly and equably allocated into eight groups and were investigated for 35 days.During the experiment,laying-egg performance was recorded.Blood and liver were sampled on days 28 for serum T3 and T4 and IDⅠactivity of liver.The results showed that SP had a significant effect on the production performance of hen.Se source and level both had a significant effect on liver IDⅠactivity and serum T3 and T4 of hen.The supplementation of SP or probiotics increased the laying rate of hen,hen day egg production and mean egg weight,and decreased the ratio of feed to egg,whereas the addition of SS did not.The addition of either SP or SS increased liver IDⅠactivity and serum T3,and decreased T4 of hen.Especially when SP was added,the liver IDⅠactivity and serum T3 of hen increased and the serum T4 of hen decreased as supplemental Se level increased.The supplementation of probiotics had not an effect on liver IDⅠactivity,but increased serum T3 and decreased T4 of hen.It was concluded that there was a better effect of supplementating SP than that of supplementating SS or probiotics.