植物单宁及其对动物的作用研究进展

对植物中单宁含量、单宁对动植物的影响及降低单宁含量的方法进行了综述。植物单宁是广泛存在于植物体内的一类多元酚化舍物,是植物进化过程中由碳水化舍物代谢衍生出来的一种自身保护性物质。一般认为单宁在维管植物中有两种存在形式既水解单宁和缩合单宁。单宁的含量与基因、部位、植物生长阶段、植物病虫害等有关;植物含有高度单宁可保护植物...     

植物单宁调控乳酸菌特性的研究进展及其在生产中的应用

单宁是植物的一种次级代谢产物,能够结合蛋白质形成复合物,在微生物发酵中有特殊生理作用。目前国内外学者对单宁结构、生物学特性和抑菌作用进行了深入研究。本文系统阐述了植物单宁对乳酸菌生长特性的调控作用,包括植物单宁抑菌性、不同种类乳酸菌对植物单宁适应性和代谢途径等,并对单宁在反刍动物营养与饲草加工利用中的应用进行了展望。     

单宁对反刍动物营养代谢的影响

单宁是一类广泛分布于植物中的多酚类化合物，具有多种生理活性。本文主要对单宁的理化性质、单宁在植物尤其饲料作物中的分布以及单宁对反刍动物营养代谢的影响以及应用作一综述。     

单宁对反刍动物养分利用的营养机制

植物饲料中适量的单宁含量对反刍动物养分利用有其积极作用。本文从分析单宁的理化性质入手,详细综述了植物饲料中单宁的营养作用机制、抗营养作用、去除措施以及研究展望,以期为有效利用含单宁的植物饲料提供理论参考。     

植物单宁的生物活性及在动物饲料中应用

病原微生物的耐药性已经对人类和动物的健康造成了威胁,引起了全球的关注。欧盟在2006年开始在饲料中禁用抗生素促生长剂。禁抗后,欧盟的畜牧业在寻找替代抗生素的方法方面,做了大量尝试和深入的科学研究。近年来的研究和实践表明植物单宁提取物,对动物和人的健康有许多好处。本文综述了不同种类的单宁(可水解单宁、缩合单宁)以及它们的生物活性特性,包括抑菌、抗病毒、抗寄生虫、抗氧化和收敛性等。综合这几种特性,植物单宁对控制和预防病原性腹泻具有显著、迅速效果。本文还简单介绍了植物单宁在饲料中的一些应用。基于现有科学研究结果,植物单宁可以替代抗生素促生长剂使用。由于单宁构成成分复杂,单宁提取物对动物生产性能的影响,与植物种类、单宁的构成、提取方法和添加量有关。     

单宁对反刍动物养分利用的营养机制

植物饲料中适量的单宁含量对反刍动物养分利用有其积极作用.本文从分析单宁的理化性质入手,详细综述了植物饲料中单宁的营养作用机制、抗营养作用、去除措施以及研究展望,以期为有效利用含单宁的植物饲料提供理论参考.     

饲料中植物单宁的抗营养性及其生物降解

由于植物单宁分子结构和化学性质的特殊性 ,使其对食草动物具有抗营养作用。植物单宁的生物降解是解决其抗营养作用的有效途径。本文综述了对植物单宁的抗营养性及其生物降解的研究进展 ,并根据作者本人的研究体会 ,对其机理进行了阐述。     

单宁对反刍动物的影响及其含量测定

针对近30年来有关单宁在反刍动物营养作用方面的研究进展,从单宁的理化性质、单宁对反刍动物的影响作用、单宁在饲用植物中的含量及其影响单宁含量的因素和单宁测定方法4个方面作了比较全面的评述。     

单宁对反刍动物的抗营养作用机理及其消除措施

本文从分析植物单宁的理化性质入手,综述了植物饲料中单宁的抗营养作用机制及去除措施。     

单宁在植物-土壤氮循环中作用的研究进展

单宁是高等植物产生的次级代谢产物。单宁和单宁-有机氮络合物在植物与土壤间的氮循环过程中扮演着重要的角色。单宁参与氮素循环的机制主要包括络合有机氮、影响土壤微生物活性以及影响土壤酶活性。以往的研究并未深入探讨单宁对各种有机氮的络合能力,以及菌根真菌和腐生真菌对单宁-有机氮络合物的降解机制。因此,本研究着重讨论了单宁对各种有机氮的络合能力、络合物的降解机制、单宁对土壤酶活性的抑制作用以及单宁对土壤微生物的影响,并综述了单宁在氮循环过程中的作用,如减缓凋落物分解,抑制净氮矿化,影响净硝化和氮固持等。结果表明:单宁能够络合大部分有机氮;单宁的结构和浓度可显著影响其对土壤酶活性和净氮矿化的抑制效果以及对土壤微生物活性和多样性的作用,该结论可为进一步理解单宁在植物与土壤间氮循环过程中的角色奠定基础。     

The influence of selected tannin-containing plant species on the tenacity of pathogenic bacteria in an in-vitro rumen system. 1. Communication: the influence of selected plant species on the tenacity of Cl. perfringens

The effect of plant species containing tannins on the tenacity of Cl. perfringens was elucidated. Trials were purchased in physiological saline solution and in a rumen-fluid-medium under anaerobic conditions. The results obtained show, that within minutes the tenacity of Cl. perfringens can be reduced by some of the tested plant material not only in physiological saline solution but also in a rumen-fluid-medium. The results indicate that the reaction of some vegetable tannins and Clostridium perfringens germs is a specific one and could be used in controlling diseases caused by Clostridium perfringens.     

In vitro antiviral activity of chestnut and quebracho woods extracts against avian reovirus and metapneumovirus

Field evidences have suggested that a natural extract, containing tannins, could be effective against poultry enteric viral infections. Moreover previous studies have shown that vegetable tannins can have antiviral activity against human viruses. Based on this knowledge three different Chestnut (Castanea spp.) wood extracts and one Quebracho (Schinopsis spp.) wood extract, all containing tannins and currently used in the animal feed industry, were tested for in vitro antiviral activity against avian reovirus (ARV) and avian metapneumovirus (AMPV). The MTT assay was used to evaluate the 50% cytotoxic compounds concentration (CC₅₀) on Vero cells. The antiviral properties were tested before and after the adsorption of the viruses to Vero cells. Antiviral activities were expressed as IC₅₀ (concentration required to inhibit 50% of viral cytopathic effect). CC₅₀s of tested compounds were >200 μg/ml. All compounds had an extracellular antiviral effect against both ARV and AMPV with IC₅₀ values ranging from 25 to 66 μg/ml. Quebracho extract had also evident intracellular anti-ARV activity (IC₅₀ 24 μg/ml). These preliminary results suggest that the examined vegetable extracts might be good candidates in the control of some avian virus infections. Nevertheless further in vivo experiments are required to confirm these findings.     

In vitro antiviral activity of chestnut and quebracho woods extracts against avian reovirus and metapneumovirus

Field evidences have suggested that a natural extract, containing tannins, could be effective against poultry enteric viral infections. Moreover previous studies have shown that vegetable tannins can have antiviral activity against human viruses. Based on this knowledge three different Chestnut (Castanea spp.) wood extracts and one Quebracho (Schinopsis spp.) wood extract, all containing tannins and currently used in the animal feed industry, were tested for in vitro antiviral activity against avian reovirus (ARV) and avian metapneumovirus (AMPV). The MTT assay was used to evaluate the 50% cytotoxic compounds concentration (CC₅₀) on Vero cells. The antiviral properties were tested before and after the adsorption of the viruses to Vero cells. Antiviral activities were expressed as IC₅₀ (concentration required to inhibit 50% of viral cytopathic effect). CC₅₀s of tested compounds were >200 μg/ml. All compounds had an extracellular antiviral effect against both ARV and AMPV with IC₅₀ values ranging from 25 to 66 μg/ml. Quebracho extract had also evident intracellular anti-ARV activity (IC₅₀ 24 μg/ml). These preliminary results suggest that the examined vegetable extracts might be good candidates in the control of some avian virus infections. Nevertheless further in vivo experiments are required to confirm these findings.     

饲草中缩合单宁的研究进展

 饲料中高浓度的缩合单宁会降低动物对营养物质的消化利用率,影响自愿采食量,甚至损伤肠胃。适宜含量的缩合单宁,又能阻止臌胀病、肺水肿的发生,降低寄生虫病害的影响,改善肉质品味,提高动物的生产性能。论文概述了缩合单宁的营养作用、抗营养作用,影响饲草缩合单宁含量的因素,以及控制缩合单宁含量的方法,以便在实践中合理应用缩合单宁。     

单宁在植物-土壤氮循环中作用的研究进展

单宁是高等植物产生的次级代谢产物。单宁和单宁-有机氮络合物在植物与土壤间的氮循环过程中扮演着重要的角色。单宁参与氮素循环的机制主要包括络合有机氮、影响土壤微生物活性以及影响土壤酶活性。以往的研究并未深入探讨单宁对各种有机氮的络合能力,以及菌根真菌和腐生真菌对单宁-有机氮络合物的降解机制。因此,本研究着重讨论了单宁对各种有机氮的络合能力、络合物的降解机制、单宁对土壤酶活性的抑制作用以及单宁对土壤微生物的影响,并综述了单宁在氮循环过程中的作用,如减缓凋落物分解,抑制净氮矿化,影响净硝化和氮固持等。结果表明:单宁能够络合大部分有机氮;单宁的结构和浓度可显著影响其对土壤酶活性和净氮矿化的抑制效果以及对土壤微生物活性和多样性的作用,该结论可为进一步理解单宁在植物与土壤间氮循环过程中的角色奠定基础。     

Effects of tannins in animal nutrition

Tannins are watersoluble plant polyphenols that precipitate proteins. According to their chemical structure they can be divided into condensed tannins and hydrolysable tannins. Altogether, tannins are reported to have various physiological effects like anti-irritant, antisecretolytic, antiphlogistic, antimicrobial and antiparasitic effects. Phytotherapeutically tannin-containing plants are used to treat nonspecific diarrhoea, inflammations of mouth and throat and slightly injured skins. Studies with ruminants have also demonstrated that the denaturing properties of tannins can possibly be used to improve protein supply to the small intestine. Besides anthelmintic effects of condensed tannins have been observed in sheep and goats. On the other hand high tannin concentrations resulted in reduced animal performances and health disorders as well in ruminants as in monogastriers. Further scientific research is therefore needed to clarify whether tannins can be effectivly used in livestock feeding, for example in prophylaxis of diarrhoea or parasitic control.     

The influence of dietary chestnut and quebracho tannins mix on rabbit meat quality

Tannins were recently evaluated as feed additives in order to increase antioxidant compounds in animal diet, mainly to enhance resistance to lipid oxidation in meat. Rabbit meat is one of the most susceptible animal products, thus the main aim of this study was to evaluate the capacity of tannins to elongate shelf life of rabbit meat. Ninety hybrid rabbits were fed with three different diets: basal diet (control, C) and basal diet supplemented with 0.3% or 0.6% of tannins mix. Meat samples were refrigerated as raw at 4°C up to 11 days and analysed both as raw and cooked for physical‐chemical characteristics, fatty acids profile, lipid oxidation and antioxidant capacity. Results showed that dietary tannins affected meat colour of raw samples (mostly yellowness). Lipid peroxidation (TBARS) of raw samples was lower in tannins group than C group; a further inhibition of peroxidation was showed also in cooked samples only by the highest dose of tannins mix. Moreover, antioxidant capacity (ABTS) of raw samples increased with the percentage of tannins. In conclusion, supplementation with 0.6% of tannins mix seems to positively affect the lipid peroxidation and antioxidant capacity of meat without modifying the intrinsic characteristics of rabbit meat.     

桃金娘鞣质抗猪流行性腹泻病毒作用研究

为测试桃金娘鞣质对猪流行性腹泻病毒(PEDV)的影响,体外试验以PEDV感染PK细胞为模型,采用细胞病变(CPE)效应法、MTT比色法检测细胞存活率,测定桃金娘鞣质抑制PEDV增殖的半数有效浓度(EC_(50))和治疗指数(TI),同时设利巴韦林对照组;体内试验以PEDV感染昆明种小鼠为模型,60只昆明种小鼠随机均分为6组,设桃金娘鞣质高剂量组、中剂量组、低剂量组、利巴韦林对照组、病毒对照组、健康对照组,采用实时荧光定量PCR法检测肠系膜淋巴结PEDV含量,观察桃金娘鞣质抗PEDV增殖能力。结果显示,桃金娘鞣质能明显抑制PEDV引起的细胞病变,半数有效浓度为0.021 mg/mL,不如利巴韦林0.0098 mg/mL(P0.05);治疗指数为361.9,优于利巴韦林214.28(P0.05);桃金娘鞣质能影响PEDV在小鼠体内的增殖数量,并呈现一定量效关系;桃金娘鞣质各剂量组小鼠肠系膜淋巴结PEDV含量均低于病毒对照组(P0.05),高、中剂量组小鼠肠系膜淋巴结PEDV含量均低于利巴韦林对照组(P0.05),小鼠肠系膜淋巴结PEDV含量在桃金娘鞣质高、中、低剂量组间也存在显著差异(P0.05)。试验表明,桃金娘鞣质具有体外、体内抗PEDV药理活性,有进一步开发抗病毒药物的价值。