饲粮锌水平对笼养蛋雏鸭生长性能、抗氧化功能及免疫器官发育的影响

本试验旨在研究饲粮锌水平对笼养蛋雏鸭生长性能、抗氧化功能及免疫器官发育的影响.试验采用单因素完全随机分组设计,选择健康1日龄金定蛋雏鸭180只,随机分成5组,每组6个重复,每个重复6只鸭.对照组(Ⅰ组)饲喂基础饲粮,试验组(Ⅱ～Ⅴ组)分别饲喂在玉米-豆粕型基础饲粮中添加20、40、60、80 mg/kg锌(ZnSO4·7H2O)的试验饲粮.试验期4周.结果表明:1)Ⅲ、Ⅳ组蛋雏鸭的料重比和Ⅲ组的平均日增重显著高于对照组(P＜0.05),雏鸭平均日增重、料重比随饲粮锌水平的增加呈明显的二次曲线变化,以此为指标估测的锌适宜添加水平分别是50.4和54.7 mg/kg;2)Ⅲ组血清和肝脏总抗氧化能力(T-AOC)、血清铜锌超氧化物歧化酶( CuZn-SOD)活性、肝脏丙二醛(MDA)含量、肝脏谷胱甘肽过氧化物酶(GSH-Px)活性与对照组相比差异显著(P＜0.05),估测的锌适宜添加水平分别是44.6、47.8、55.7、43.4、54.2 mg/kg,而血清MDA含量、血清GSH-Px活性和肝脏CuZn-SOD活性与对照组差异不显著(P＞0.05);3)Ⅲ组胸腺指数、脾脏指数、法氏囊指数均显著高于对照组(P＜0.05).由此可见,蛋雏鸭采食玉米-豆粕型基础饲粮(含锌33.3 mg/kg)时,锌的适宜添加水平为55.7 mg/kg.

Effects of Dietary Zinc Level on Growth Performance, Antioxidant Function and Immune Organ Development of Caged Egg-Type Ducklings

This experiment was conducted to study the effects of dietary zinc level on growth performance,antioxidant function,and immune organ development of caged egg-type ducklings.Using a single factor completely randomized design,a total of 180 one-day-old Jinding egg-type ducklings were randomly divided into 5 groups with 6 replicates per group and 6 ducks in each replicate.Ducks in control group(group Ⅰ) were fed a basal diet,and the others in experimental groups(groups Ⅱ-Ⅴ) were fed the basal diet supplemented with 20,40,60 and 80 zinc(as ZnSO4·7H2O),respectively.The experiment lasted for 4 weeks.The results showed as follows: 1) the feed to gain in groups Ⅲ,Ⅳ and average daily gain in group Ⅲ were significantly higher than those in the control group(P<0.05).The average daily gain and feed to gain were changed quadratically with increasing dietary zinc level,and the estimation values of optimal dietary zinc level were 50.4 and 54.7 mg/kg,respectively.2) The serum and liver total anti-oxidation capability(T-AOC),serum Cu-Zn-superoxide dismutase(CuZn-SOD) activity,liver malondialdehyd(MDA) content,and liver glutathion peroxidase(GSH-Px) activity in group Ⅲ had significant differences compared with the control group(P<0.05),and the estimation values of optimal dietary zinc level were 44.6,47.8,55.7,43.4 and 54.2 mg/kg,respectively,but the serum MDA content,serum GSH-Px activity,and liver CuZn-SOD activity in group Ⅲ had no significant difference compared with the control group(P>0.05).3) The thymus index,spleen index and bursa of Fabricius index in group Ⅲ were significantly higher than those in the control group(P<0.05).In conclusion,the optimal dietary zinc level of caged egg-type ducklings fed corn-soybean meal basal diet(33.3 mg/kg zinc) is 55.7 mg/kg.