维生素A对笼养育成蛋鸭免疫机能和相关激素分泌的影响

Effects of Vitamin A on Immune Function and Correlated Hormone Secretion in Growing Laying Ducks in Cage

本文旨在研究维生素A(VA)对笼养育成蛋鸭免疫机能和相关激素分泌的影响。试验选用28日龄平均体重(0.37±0.01)kg的金定蛋鸭216只,随机分为6组,每组6个重复,每个重复6只鸭,分别饲喂在日粮基础中添加0、2 250、5 500、8 250、12 000和15 000 IU/kg VA的试验日粮,试验期7周。结果表明:与对照组相比,添加VA对蛋鸭胸腺鲜重、法氏囊鲜重及其指数影响差异不显著(P>0.05),5 500 IU/kg VA添加组脾脏鲜重和脾脏指数显著增加(P<0.05)。添加VA可显著提高ALB含量(P<0.05),5 500～15 000 IU/kg VA添加组显著或极显著的提高了血清中GLB含量(P<0.05或P<0.01)。添加VA对IgG、IgM和IL-2影响差异不显著(P>0.05)。T_3、T_4含量随VA添加水平的升高均呈先增加后降低的趋势,以8 250 IU/kg VA添加组最高。15 000 IU/kg VA添加组血清GH含量显著低于对照组和8 250 IU/kg VA添加组(P<0.05)。结果显示,日粮中添加5 500～8 250 IU/kg VA可提高生长期蛋鸭机体的免疫机能,调节相关激素分泌。

This study was designed to evaluate the effects of vitamin A （VA） on immune function and correlated hormone secretion in growing laying ducks. Two hundred and sixteen Jinding ducks with an average body weight of （0.37± 0.01） kg were chosen and randomly divided into 6 groups with 6 replicates of 6 ducks in each replicate. Ducks in six groups were fed basal diet with supplements of 0, 2 250, 5 500, 8 250, 12 000, 15 000 IU/kg VA, respectively. The trial lasted for 7 weeks. The result showed that compared with control group, the weight and indices of thymus and bursal were not influenced by different levels of VA （P〉0.05）, spleen and spleen indices increased significantly in 5 500 IU/kg VA group （P〈0.05）. The ALB increased significantly by adding different levels of VA （P〈0. 05）, the GLB significantly or extremely significantly increased when VA supplemental levels were 5 500, 8 250, 12 000 and 15 000 IU/kg （P〈0.05 or P〈0.01）. There were no significant differences among the groups in IgG, IgM and IL-2 （P〉0.05）. The content of T3, T4 first increased and then decreased as the level of VA increased （P〉0.05）, and the highest group was 8 250 IU/kg VA group. The GH content in 15 000 IU/kg VA group was much lower than those in the control group and the 8 520 IU/kg VA group （P〈0.05）. It was concluded that adding 5 500-8 250 IU/kg VA to the diet could improve immune function and regulate correlated hormone secretion of growing laying ducks.