中文摘要：

探讨在日粮中添加内毒素（ET）对雏鸡免疫器官肥大细胞（MC）的影响,为ET致雏鸡免疫器官的免疫刺激或损伤提供理论依据。随机挑选140只28日龄公雏鸡随机分为5组。各组分别在基础日粮中添加0、500、1 000、1 500、2 000μg/kg的ET。在34、41、48d晚禁食,自由饮水,次日各组随机抽取7个样本,颈静脉放血处死,取胸腺,法氏囊和脾脏用Carnoy′s液固定,TB染色显示MC。结果显示,第35天和第42天时,各试验组胸腺髓质MC与对照组比较,差异显著（P〈0.05）或极显著（P〈0.01）;各试验组法氏囊MC与对照组比较显著（P〈0.05）或极显著（P〈0.01）减少。第35天和第49天时,500μg/kg组显著（P〈0.05）或极显著（P〈0.01）高于其他试验组;试验第35天和第42天时,各试验组与对照组脾脏MC数比较,显著（P〈0.05）或极显著（P〈0.01）减少;第35天,500μg/kg组脾脏MC数显著（P〈0.05）高于1 500μg/kg组;第42天,500μg/kg组脾脏MC数显著（P〈0.05）或极显著（P〈0.01）高于其他试验组。结果表明,日粮中添加内毒素可诱导雏鸡免疫器官MC数量减少。

英文摘要：

In order to investigate the effects of endotoxin（ET）on the mast cells（MC）of main immune organs in chicks,one hundred and forty 28-day old male chicks were randomly divided into five groups：Control group,500μg/kg ET,1000μg/kg ET,1500μg/kg ET,2000μg/kg ET group.On 35,42,49days of ages,7 birds were randomly taken from each groups,the thymus,bursa of fabricius and spleen were collected and fixed in Carnoy′s solution.Paraffin sections were made.Toluidine blue staining were used.At 35th and 42th day,the number of MC in thymus decreased significantly（P〈0.01or P〈0.05）.At 35th and 42th day,the number of MC in bursa of fabricius decreased significantly（P〈0.01or P〈0.05）.At 35th and 42th day,the MC number of 500μg/kg group was higher（P〈0.05orP〈0.01）than that of other experiment groups.At 35th and 42th day,the number of MC in spleen decreased significantly（P〈0.01 or P〈0.05）.At 35th day,the MC number of 500μg/kg group was significantly（P〈0.05）or（P〈0.01） higher than that of 1500μg/kg group.At 42th day,the MC number of 500μg/kg group was higher than that of other experiment groups（P〈0.05or P〈0.01）.The results showed that after administrating different doses of ET,the MC number of the immune organs decreased.