【摘要】 试验旨在研究日粮有机锌水平对产蛋后期蛋鸡生产性能、免疫功能和抗氧化指标的影响。选取体重和产蛋率相近的57周龄海兰灰蛋鸡960只,随机分为4组,每组8个重复,每个重复30只。参照NRC(1994)蛋鸡饲养标准,结合海兰公司推荐日粮营养水平,设计玉米-豆粕型基础日粮(基础日粮锌水平35.08 mg/kg)。试验期16周,其中预试期2周(57～58周龄),各处理组均饲喂不补充锌的基础日粮;正试期14周(59～72周龄),对照组在基础日粮中添加80 mg/kg硫酸锌,试验组分别在基础日粮中添加20、40、80 mg/kg的羟基蛋氨酸螯合锌(MHA-Zn),常规饲养管理。结果表明:(1)锌源和添加水平对蛋鸡的产蛋率、平均蛋重、平均日采食量、料蛋比等产蛋性能指标没有显著影响(P>0.05),但添加40、80 mg/kg MHA-Zn显著降低蛋鸡破蛋率(P<0.05);(2)各处理组血清免疫球蛋白IgG和IgM水平,新城疫病毒抗体水平无显著差异(P>0.05),但添加40 mg/kg MHA-Zn显著提高蛋鸡H5亚型禽流感病毒抗体水平(P<0.05);(3)有机锌与无机锌相比,具有显著提高机体抗氧化能力的优势(P<0.05),主要表现为提高蛋鸡血清和肝脏中铜锌-超氧化物歧化酶(Cu/Zn-SOD)活性和总抗氧化能力(T-AOC),降低丙二醛(MDA)含量。综上所述,建议产蛋后期蛋鸡日粮中MHA-Zn添加水平为40 mg/kg。更多还原

【Abstract】 This study was aimed to study the effects of methionine hydroxy analog chelate zinc(MHA-Zn) on production performance, immune function and anti-oxidative parameters of laying hens at the late of laying cycle. A total of 960 layers(Hy-line Grey, 57 weeks of age) were randomly assigned into 4 groups with 8 replicates per treatment.The experiment lasted for 16 weeks: During the first 2 weeks, birds were fed a basal diet without extra zinc(35.08 mg/kg Zn), while during the ensuing 14 weeks, 4 levels of Zn(Inorganic Zn: 80 mg/kg; Organic Zn: 20, 40, 80 mg/kg) were added to diet, respectively. The results showed that neither Zn source nor level could influence laying rate, average egg weight, average daily intake, feed to egg ratio(P>0.05), while groups supplemented with 40 or 80 mg/kg MHA-Zn were significantly decreased broken egg rate(P<0.05). In addition, no remarkable difference was found in IgM, IgG and antibody level against Newcastle disease virus(P>0.05), while dietary 40 mg/kg MHA-Zn was dramatically increased antibody level against H5 subtype avian influence virus(P<0.05). Moreover, compared with inorganic zinc, MHA-Zn significantly promoted the anti-oxidative capacity(P<0.05), mainly by increasing the activity of Cu/Zn-SOD and T-AOC and decreasing MDA content in serum and liver. In conclusion, the optimal supplementation of MHA-Zn in diet of aged laying hen was 40 mg/kg.更多还原