本试验旨在研究饲粮中添加卵黄免疫球蛋白（IgY）对雏鸡生长性能和免疫机能的影响。选取同一批出雏、体重相近的1日龄罗曼褐蛋鸡公雏240只，随机分为2组（对照组和试验组），每组6个重复，每个重复20只鸡。对照组饲喂基础饲粮，试验组在对照组饲粮基础上添加0.1%的IgY。试验期5周。分别于1、3、5周龄，每个重复选取接近该重复平均体重的试验鸡2只，称重、采血并用于血清免疫指标测定，然后取免疫器官、空肠食糜用于相关指标测定。结果表明：1）与对照组相比，试验组1、3、5周龄雏鸡平均日增重有增大的趋势（0.05 < P < 0.10）。2）试验组1、5周龄雏鸡胸腺相对重和1周龄脾脏相对重显著高于对照组（P<0.05），试验组1、5周龄雏鸡法氏囊、脾脏、胸腺中IgY含量与对照组差异均不显著（P>0.05）。3）试验组1周龄雏鸡血清球蛋白、α-干扰素、白细胞介素-2含量和溶菌酶活性，3周龄雏鸡血清总蛋白、球蛋白和白细胞介素-2含量，5周龄雏鸡血液淋巴细胞数量均显著高于对照组（P<0.05）。4）试验组1周龄雏鸡肠道食糜中分泌型免疫球蛋白A含量显著高于对照组（P<0.05）。由此可知，雏鸡饲粮中添加IgY可以促进雏鸡1~5周龄生长性能和免疫机能的提高，但从提高免疫机能的角度看，育雏前期（1~3周龄）的作用效果更为明显。

This experiment was conducted to study the effects of dietary yolk immunoglobulin (IgY) on growth performance and immune function of chicks. Two hundred and forty one-day-old Roman rooster hens with same batch of hatching and similar body weight were randomly divided into 2 groups (control and experimental groups) with 6 replicates in each group and 20 chicks in each replicate. Chicks in the control group were fed with a basal diet, and the others in the experimental group fed the basal diet supplemented with 0.1% IgY. The experiment lasted for 5 weeks. At the age of 1, 3 and 5 weeks, 2 chickens with average weight of each replicate were weighed, slaughtered, and the blood was collected for the serum immune parameters, and then the immune organ, jejunum chyme were taken and used for the determination of relevant indicators. The results showed as follows:1) compared with the control group, the average daily gain of chicks in experimental group had a tendency to increased at the age of 1, 3 and 5 weeks (0.05 < P < 0.10). 2) The thymus relatively weight of chicks at the age of 1 and 5 weeks and spleen relatively weight of chicks at age of 1 week in experimental group were significantly higher than those in control group (P<0.05). The content of IgY in bursa of Fabricius, spleen and thymus of chicks at the age of 1 and 5 weeks in experimental group had no significant difference with what in control group (P>0.05). 3) The content of globulin, α-interferon interleukin-2 and the activity of lysozyme in serum of chicks at the age of 1 week, the content of total protein, globulin and interleukin-2 in serum of chicks at the age of 3 weeks, and the number of blood lymphocytes of chicks at the age of 5 weeks in experimental group were significantly higher than those in control group (P<0.05). 4) The content of secretory immunoglobulin A in intestinal tract chyme of chicks at the age of 1 week in experimental group was significantly higher than that in control group (P<0.05). In conclusion, dietary supplementation of IgY can enhance growth performance and immune function at the age of 1 to 5 weeks. But from the perspective of improving immune function, the effect at early stage of brood (1 to 3 weeks of age) is more obvious.