日粮添加维生素A对肉鸡和蛋鸡生长性能及免疫功能的影响

Effects of Dietary Vitamin A Supplementation on Growth Performance and Immune Function of Broilers and Laying Hens

试验研究了不同的维生素A(VA)添加水平对肉鸡和蛋鸡的生长性能及机体免疫功能的影响。试验选用1日龄的雌性蛋鸡和雌性肉鸡各270只,分别随机分成3个处理,每个处理6个重复,每个重复15只,分别饲喂含维生素A0(对照)、4000和20000IU/kg的日粮,饲养试验时间为84d。试验结果表明,日粮添加维生素A为0IU/kg处理的肉鸡和蛋鸡的采食量显著高于添加维生素A的各处理(P<0.05);日粮维生素A添加水平对肉鸡和蛋鸡的免疫器官指数(胸腺指数、脾脏指数和法氏囊指数)无显著影响(P>0.05);对照的肉鸡和蛋鸡异嗜粒细胞/淋巴细胞(H/L)高于其他处理(P>0.05);肉鸡和蛋鸡绵羊红细胞(SRBC)抗体滴度和新城疫(ND)抗体滴度随着日粮维生素A添加水平的升高而升高;日粮添加4000IU/kg维生素A处理的肉鸡和蛋鸡钥孔戚血蓝蛋白(KLH)抗体滴度、白蛋白浓度和白介素-2(IL-2)的浓度最高。蛋鸡的免疫器官指数和血清白蛋白浓度显著高于肉鸡(P<0.05);肉鸡和蛋鸡的其他免疫指标差异不显著(P>0.05)。综上所述,日粮添加4000IU/kg维生素A能提高肉鸡和蛋鸡的生长性能和免疫功能,当添加水平达到20000IU/kg时,可对生长性能和免疫机能产生不利影响。肉鸡和蛋鸡的主要免疫指标没有显著差异。

This experiment was conducted to evaluate the effects of vitamin A（VA）supplementation in diet on growth performance and immune function of laying hens and broilers.Two hundred and seventy female laying hens and 270 female broilers were assigned to 3 dietary treatments with 6 replicates（15 chickens per replicate）,respectively.These laying hens and broilers received the same basal diet supplemented with 0,4 000,20 000 IU/kg VA,respectively.The feeding trial lasted for 84 days.Results showed as follows：the 0 IU/kg VA supplemental treatment had higher feed intake of laying hens and broilers than other treatments（P0.05）;VA supplemental levels had no significant effects on immune organ indices（thymus index,spleen index and index of bursa of Fabricius）（P0.05）;the 0 IU/kg VA supplemental treatment had higher heterophil to leukocyte ratio of laying hens and broilers than other treatments（P0.05）;the sheep red blood cell antibody titers and the Newcastle disease antibody titers of laying hens and broilers were increased with VA levels increasing;the keyhole lympet hemocyanin antibody titers,the concentrations of serum albumin and IL-2 of laying hens and broilers in the 4 000 IU/kg VA supplemental treatment were the highest.Immune organ indices and albumin concentration of the laying hens were significantly higher than those of broilers（P0.05）;there was no significant difference on the other immune indices between laying hens and broilers（P0.05）.The present study suggested that 4 000 IU/kg VA supplementation could improve growth performance and immune function of laying hens and broilers.When the supplemental level reached 20 000 IU/kg,it seemed to exert negative effects on growth performance and immune function.Immune indices between laying hens and broilers had not significant difference.