紫色达利菊缩合单宁化学结构的鉴定及其对绵羊消化性能影响的研究
发布时间：2018-10-25 12:46
【摘要】：紫色达利菊体内含有高浓度的缩合单宁,具有很强的抗大肠杆菌O157:H7的能力,因此饲喂紫色达利菊为日粮控制反刍动物生产中大肠杆菌O157:H7的水平提供了有效措施。本研究通过4个试验系统研究了紫色达利菊缩合单宁化学结构的特征以及结构与生物活性的关系;不同贮藏方式对紫色达利菊缩合单宁含量以及瘤胃和小肠消化的影响;饲喂紫色达利菊对绵羊营养物质消化、健康条件以及后肠微生物区系的影响,旨在为紫色达利菊缩合单宁在反刍动物生产中的推广应用和作用机制提供理论依据。主要研究结果如下:1.紫色达利菊中缩合单宁的含量和化学结构在不同组织和不同生长期内都有变化。在所有生长期内花中缩合单宁的含量最多,茎中最少;茎中缩合单宁的含量随植物的成熟而减少。紫色达利菊缩合单宁主要是由原花青定单宁组成,主要单体是表儿茶素,其次是表没食子儿茶素。所有生长期内叶中原花青定单宁的含量均高于茎和花。茎中缩合单宁的聚合度最高。随着植物的成熟,茎中原花青定单宁的含量逐渐降低,缩合单宁的聚合度则逐渐增大。叶中缩合单宁的蛋白结合能力强于茎和花;而叶中缩合单宁在早花期的蛋白结合能力最高。2.青贮和晒制干草显著增加了紫色达利菊中结合缩合单宁的含量。干草紫色达利菊降低了粗蛋白和粗纤维的瘤胃降解率,增加了粗蛋白的小肠消化率。相反,青贮紫色达利菊增加了粗蛋白的瘤胃降解率而降低了粗蛋白的小肠消化率,对粗纤维的瘤胃降解率没有影响。青贮紫色达利菊中的结合缩合单宁降低了干物质和粗蛋白的瘤胃降解率,但对粗纤维的瘤胃降解率和干物质以及粗蛋白的小肠消化率没有影响。3.饲喂紫花苜蓿-紫色达利菊混合日粮(缩合单宁摄入量为36g kg~（-1）干物质)对绵羊饲料采食量、有机物和中性洗涤纤维的消化率没有影响,但是降低了粗蛋白消化率。相比单独饲喂紫花苜蓿有效降低了绵羊粪中大肠杆菌O157:H7的排泄量,同时增强了绵羊血清抗氧化能力。4.通过454焦磷酸测序技术对绵羊后肠微生物区系进行了研究,发现紫色达利菊缩合单宁在日粮中含量为36 g kg~（-1）干物质时尽管改变了一些特定的细菌类群,但对绵羊后肠微生物区系几乎没有影响。综上所述,本研究表明紫色达利菊能改善反刍动物粗蛋白利用率和动物健康状况,具有推广价值。并为增强反刍动物畜产品安全提供了一种有效的收获前措施。
[Abstract]:High concentration of condensed tannin was found in the body of Thalanthemum purpurea, which had strong ability to resist Escherichia coli O157:H7, so feeding purple Dalium provided effective measures to control the level of Escherichia coli O157:H7 in ruminant production. In this study, the chemical structure and the relationship between the structure and bioactivity of the condensed tannin were studied by four experimental systems, and the effects of different storage methods on the content of the condensed tannin and the digestion of rumen and small intestine were also studied. In order to provide theoretical basis for the popularization and application of condensed tannin in ruminant production and the mechanism of its action, the effects of feeding purple Dalium on nutrient digestion, health conditions and microflora of hindgut in sheep were studied. The main results are as follows: 1. The content and chemical structure of condensed tannin in purple Dalium changed in different tissues and different growth stages. The content of condensed tannin was the highest in all growth stages and the least in stem, and the content of condensed tannin in stem decreased with the maturation of plant. The condensed tannin is mainly composed of the original flower green order tannin, the main monomer is epicatechin, and the next is epigallocatechin. The content of procyanidin in inner leaves of all growing period was higher than that in stems and flowers. The degree of polymerization of condensed tannins in stems was the highest. With the maturation of plants, the content of procyanidin in stems decreased gradually, and the degree of polymerization of condensed tannins increased gradually. The protein binding ability of condensed tannin in leaves was stronger than that in stems and flowers, while the protein binding ability of condensed tannins in leaves was the highest at early flowering. 2. Silage and sundry significantly increased the content of condensed tannins in purple dahlieju. The degradation rate of crude protein and crude fiber in rumen was decreased and the digestibility of small intestine of crude protein was increased. On the contrary, silage purple Dalium increased the rumen degradation rate of crude protein, decreased the small intestine digestibility of crude protein, and had no effect on the rumen degradation rate of crude fiber. The combined tannin in silage purple Dalium decreased the rumen degradation rate of dry matter and crude protein, but had no effect on the rumen degradation rate of crude fiber and dry matter and the digestibility of small intestine of crude protein. The diet fed alfalfa and purple daliju (intake of condensed tannin was 36g kg~ (-1) dry matter) had no effect on feed intake, organic matter and digestibility of neutral detergent fiber, but decreased the digestibility of crude protein. Compared with alfalfa fed alone, the excretion of Escherichia coli O157:H7 in sheep feces was decreased, and the antioxidant capacity of sheep serum was increased. The microflora of sheep hindgut was studied by 454 pyrosequencing technique. It was found that the concentration of 36 g kg~ (-1) of tannin in diet changed some specific bacterial groups. But it had little effect on the microflora of sheep hindgut. To sum up, this study shows that purple Dalium can improve the utilization rate of crude protein and health status of ruminants, which is worth popularizing. It also provides an effective pre-harvest measure for enhancing the safety of ruminant animal products.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S826.5
，
本文编号：2293732
[Abstract]:High concentration of condensed tannin was found in the body of Thalanthemum purpurea, which had strong ability to resist Escherichia coli O157:H7, so feeding purple Dalium provided effective measures to control the level of Escherichia coli O157:H7 in ruminant production. In this study, the chemical structure and the relationship between the structure and bioactivity of the condensed tannin were studied by four experimental systems, and the effects of different storage methods on the content of the condensed tannin and the digestion of rumen and small intestine were also studied. In order to provide theoretical basis for the popularization and application of condensed tannin in ruminant production and the mechanism of its action, the effects of feeding purple Dalium on nutrient digestion, health conditions and microflora of hindgut in sheep were studied. The main results are as follows: 1. The content and chemical structure of condensed tannin in purple Dalium changed in different tissues and different growth stages. The content of condensed tannin was the highest in all growth stages and the least in stem, and the content of condensed tannin in stem decreased with the maturation of plant. The condensed tannin is mainly composed of the original flower green order tannin, the main monomer is epicatechin, and the next is epigallocatechin. The content of procyanidin in inner leaves of all growing period was higher than that in stems and flowers. The degree of polymerization of condensed tannins in stems was the highest. With the maturation of plants, the content of procyanidin in stems decreased gradually, and the degree of polymerization of condensed tannins increased gradually. The protein binding ability of condensed tannin in leaves was stronger than that in stems and flowers, while the protein binding ability of condensed tannins in leaves was the highest at early flowering. 2. Silage and sundry significantly increased the content of condensed tannins in purple dahlieju. The degradation rate of crude protein and crude fiber in rumen was decreased and the digestibility of small intestine of crude protein was increased. On the contrary, silage purple Dalium increased the rumen degradation rate of crude protein, decreased the small intestine digestibility of crude protein, and had no effect on the rumen degradation rate of crude fiber. The combined tannin in silage purple Dalium decreased the rumen degradation rate of dry matter and crude protein, but had no effect on the rumen degradation rate of crude fiber and dry matter and the digestibility of small intestine of crude protein. The diet fed alfalfa and purple daliju (intake of condensed tannin was 36g kg~ (-1) dry matter) had no effect on feed intake, organic matter and digestibility of neutral detergent fiber, but decreased the digestibility of crude protein. Compared with alfalfa fed alone, the excretion of Escherichia coli O157:H7 in sheep feces was decreased, and the antioxidant capacity of sheep serum was increased. The microflora of sheep hindgut was studied by 454 pyrosequencing technique. It was found that the concentration of 36 g kg~ (-1) of tannin in diet changed some specific bacterial groups. But it had little effect on the microflora of sheep hindgut. To sum up, this study shows that purple Dalium can improve the utilization rate of crude protein and health status of ruminants, which is worth popularizing. It also provides an effective pre-harvest measure for enhancing the safety of ruminant animal products.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S826.5
，
本文编号：2293732
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