氧化应激的产生及其对畜禽肝脏功能的影响与机制

现代畜牧业规模化生产中,养殖环境、饲粮构成、饲养方式等诸多因素变化可诱发畜禽产生氧化应激。氧化应激对畜禽的肝脏功能有负面作用,危害畜禽健康和生产。机体发生氧化应激时,大量的氧自由基在肝细胞内蓄积,通过损伤生物大分子物质、破坏肝细胞结构、影响细胞器功能、诱发肝细胞凋亡等,对肝脏造成严重损伤,并引发多种肝脏疾病。本文从机体氧化应激产生、氧化应激对肝脏功能的影响以及氧化应激影响肝脏功能的可能分子机制等方面进行综述,以期为缓解氧化应激危害提供理论依据。     

乳酸菌缓解氧化应激的潜在作用及机制研究进展

氧化应激是引起机体发生疾病的重要因素之一。动物经长途运输或其他外界因素刺激引起动物机体氧化应激,导致动物出现脓血症、肠炎等疾病。在研究氧化应激引起的疾病中,益生菌以潜在的天然抗氧化剂为预防和治疗不同疾病提供新的途径,因此用天然抗氧化剂来缓解因氧化应激引发的各种疾病成为近几年国内外学者研究的热点。文章综述了目前国内外对乳酸菌缓解氧化应激的研究现状,乳酸菌对氧化应激的潜在缓解作用以及其发挥的抗氧化功能,并对其发展趋势进行了展望。     

养殖场在使用微生态制剂时应注意维护微生态的平衡

<正>1影响微生态平衡的因素1.1应激因素应激因素主要通过改变机体内分泌系统,影响机体生理功能和微环境来对微生态造成影响。例如在动物体处于长时间的恐惧状态时,消化功能将处于抑制状态,肠道蠕动和分泌变弱,对肠道微生态的影响是十分明显的。1.2小环境动物机体所处的小环境直接对动物机体产生作用,这种作用多以应     

维生素E对冷应激雏鸡抗氯化功能的影响

寒冷是北方寒区动物最普遍的应激原，寒冷应激所引起的动物生长缓慢、抗病性差、甚至死亡是制约北方畜牧业和养殖业发展的主要因素之一。维生素E具有抗应激、抗疲劳、抗氧化、增强免疫能力等功能，它作为一种饲料添加剂在畜牧业中已得到广泛的应用。国内外众多学者在冷应激对动物机体的影响方面进行了广泛研究，已有的大量研究表明，冷应激可对机体免疫系统产生影响，可改变多种细胞功能和免疫参数，但关于维生素E的抗应激作用在禽类中的研究还比较少。     

奶牛氧化应激与抗氧化的研究进展

<正>奶牛由于高强度代谢很容易受到氧化应激,氧化应激对奶牛的健康和产能具有负面影响,生产中有必要通过添加抗氧化剂来提高机体的抗氧化能力和减少氧化应激对奶牛的损害。氧化应激产生的过量自由基会导致细胞大分子的氧化修饰、功能异常及坏死,称为氧化损伤,另外氧化产物还作为内源的信号分子,对细胞凋亡和炎症起推动作用。机体的氧化应激被看作是一种代谢状态或生理状态的负荷或异常,研究表明氧化应激对动物多种慢性疾病和生产性能造成影响。奶牛容易遭受氧化应激,多个阶段的氧化应激都对奶牛健康和生产性能产生了损害,因此对奶牛氧化应激和抗氧化的研究     

自由基的研究进展

在正常生理状况下,动物体内的氧化还原状态处于相对平衡中。集约化养殖条件下,动物处在不同的应激原中;另外,现代选育的高生产性能的动物品种对环境的抗逆性能变差,加之动物的生产性能提高的同时,体内的代谢速度也随之加快,使得大多动物经常处于氧化--还原失衡的氧化应激状态。氧化应激常常会带来畜禽生产成绩下降(如:热应激使蛋鸡产蛋率下降),动物产品品质下降(如:屠宰应激产生PSE猪肉),甚至发生动物疾病(如:环境应激和营养性应激引发肉鸡腹水症)等诸多问题。本文主要综述动物体内自由基的产生、危害和清除机制的研究进展。     

奶牛氧化应激及抗氧化措施研究进展

当奶牛进行高强度代谢或者受到某些外来刺激时,机体会产生大量自由基,发生氧化应激,使奶牛机体产生氧化损伤,最终影响牛奶产量与品质,降低奶牛经济效益。文章主要对奶牛氧化应激的来源、对奶牛的影响、氧化应激对机体损伤的机制以及奶牛氧化应激缓解措施进行简单阐述。     

维生素A调节动物一氧化氮的生成及其相关机制

动物机体由于旺盛的新陈代谢或在受到外界有害因素刺激的情况下会产生大量一氧化氮(NO),进而损伤细胞中的蛋白质、类脂膜和DNA,引发细胞炎症并阻断细胞信号通路,使机体产生氧化应激。维生素A可以有效地调控NO的生成,提高机体抗氧化水平并清除自由基,预防细胞炎症及氧化应激的发生。本文主要综述了维生素A对动物NO生成的调节作用及其相关机理的研究进展,对今后深入研究其调节机理、科学补充维生素A及提高机体的抗氧化功能具有一定参考价值。     

氧化应激对断奶仔猪的影响及营养的调控作用

氧化应激与仔猪健康关系密切,营养物质影响仔猪机体的氧化还原水平和健康。仔猪出生后遭遇断奶、疾病、免疫等应激,损伤机体健康,其在一定程度上体现机体抗氧化能力的改变。本文从断奶对仔猪氧化还原系统的影响、氧化应激对断奶仔猪的影响以及营养缓解氧化应激的作用进行综述,初步探讨氧化应激作为判断仔猪健康的生物标识的可行性。     

海带多糖的抗氧化功效及其在畜牧生产上的应用

外界各种刺激造成的氧化应激会导致动物机体内氧化物质比例失衡,严重影响动物肝脏、肠道等组织器官,从而影响畜禽健康.海带多糖是一种绿色安全且具有多种生理活性的天然抗氧化剂,可缓解氧化应激带来的损伤,增强动物机体抗氧化性能.海带多糖体外和体内抗氧化活性均良好.主要对海带多糖的开发和利用、抗氧化功效以及在畜牧生产中的应用进行综...     

水生生物Nrf2-Keap1/Are信号通路的研究进展

氧化应激（oxidative stress）是指由于外界环境的刺激使机体内活性氧（ROS）增加,导致氧化/抗氧化动态平衡遭到破坏的一种应激反应。在正常情况下,动物机体内参与活性氧产生和清除的系统处于动态平衡。由于外界环境刺激或机体自身变化等原因,使ROS产生增多或其清除能力下降时,机体就会出现氧化应激（氧化胁迫）。长期或过强的氧化应激会引起水生生物生长发育缓慢、免疫机能下降、疾病发生等危害,导致水产品质量下降、营养价值降低,给水产养殖业造成严重经济损失。Nrf2-Keap1/Are信号通路在抵抗外源性或内源性氧化应激的过程中起着至关重要的作用,该信号通路在哺乳动物中得到了广泛研究,但在水生生物中的研究尚未见系统综述。作者在综合了大量文献的基础上,针对鱼类及虾蟹类等水生生物,介绍了氧化应激产生的机理、Nrf2和Keap1的分子基础、Nrf2-Keap1/Are信号通路作用方式,以及该信号通路在水生生物方面的相关研究进展等,为水生生物抗氧化应激机制的深入研究提供理论参数和相关数据支持。     

Application Progress of Selenium and Selenoprotein in Aquaculture北大核心CSCD

随着水产养殖产业的高速发展,水产养殖集约化规模扩大,养殖动物密度增大,容易造成氧化应激反应,这迫使水产养殖从业者亟需寻找无毒无害且高效的饲料添加剂以提高水产动物的抗应激能力。硒(Se)是一种人体和动物生长繁育必需的微量元素,其生物学功能主要通过硒蛋白表达,饲料中添加适量的硒能够增强水产动物的抵抗力。本文综述了硒和硒蛋白的种类以及硒对水产动物的生理机制,同时对硒在水产养殖中的应用进行综述,旨在总结不同硒源作为水产饲料添加剂在改善水产动物生长、免疫与肉质等方面的作用,为其在水产养殖中的高效应用提供科学参考。     

氧化应激与自噬

自噬是细胞依赖溶酶体对蛋白质和细胞器进行降解的过程,能帮助细胞适应各种不良刺激,在维持细胞内环境稳态和实现自我更新中起着重要作用。氧化应激是机体氧化和抗氧化系统之间的稳态被破坏而造成的应激状态。大量研究表明,氧化应激中产生的活性氧能诱导自噬产生,而自噬能缓解氧化应激造成的损伤,从而保护细胞存活。本文主要对自噬的形成过程、氧化应激诱导自噬产生机制以及自噬缓解氧化应激的途径等进行综述,以期为畜牧生产中通过调控自噬缓解氧化应激提供理论依据。     

Relevance, measurement and assessment of the antioxidative status in farm animals

Reactive oxygen species (ROS) are generated in living organisms under physiological and pathological conditions. They have to be neutralized by the antioxidative system which consists of enzymatic and non enzymatic antioxidants. Both, the activity of antioxidative enzymes and the capacity of non enzymatic antioxidants are known as the antioxidative status of the organism. If the balance between prooxidative processes and antioxidative system is disturbed oxidative stress occurs. Oxidative stress is considered to be a major risk factor for the reduction of defence mechanisms and development of diseases. The aim of the present work is to describe various aspects of the antioxidative status in several production animal species. Conclusions for management and therapy are drawn when possible. Furthermore the paper provides an overview of methods for assessment of antioxidative metabolism. Farm animals undergo several periods of severe challenge of the antioxidative system during the production cycle. Especially young animals in the first weeks of their life and animals during the periparturient period are at high risk. High yielding live stock generally have to carry a higher oxidative burden in comparison to animals which are on a medium production level or in extensive systems. Other risk factors are unsuitable or spoiled components in the diet and heat stress. Exogenous antioxidant supply can be optimized by feeding fresh roughage or silage of good quality or if necessary by using additives. Changes of the antioxidative system have been described in association with displaced abomasum (DA), abomasal volvulus (AV) and reproductive problems in swine. Pre- and postoperative supplementation of antioxidants has been used with good results as supportive treatment in therapy of cattle with DA.     

发酵豆粕在犊牛饲料中的应用进展

豆粕是一种优质的植物性蛋白来源,含有丰富的氨基酸,但也含有胰蛋白酶抑制因子、抗原蛋白以及大豆凝集素等抗营养因子,容易引起犊牛消化功能紊乱,造成营养性腹泻,限制了其在犊牛上的使用量。微生物发酵可以改善豆粕的营养价值,使抗营养因子得到充分的降解,生成的小肽和有机酸有利于犊牛消化吸收和肠道健康,进而提高犊牛断奶日增重和免疫能力,降低犊牛的腹泻率和断奶应激。本文综述了豆粕经过发酵后带来营养价值的变化,并就发酵豆粕在犊牛上的应用进行概述,为其今后在犊牛中的应用提供参考。     

The influence of land transport on animal welfare in extensive farming systems

The land transport of animals can have 3 types of influence on their welfare. First, the handling, loading, and novelty of the transport environment and experience can induce a psychological stress response in animals. Second, the withdrawal of feed and water and the need to stand and maintain balance for transport periods can cause a physiological and fatigue challenge to the animals. Finally, the thermal and physical conditions of the vehicle and journey can present a risk to the physical integrity of the transported animals.The key determinant of animal welfare is the way in which transport is conducted. The stress response during loading and the initial stages of transport may be minimized by careful handling, good design of facilities, and appropriate stocking densities and driving techniques. Where animals are not fed and watered during land transport, they vary in their ability to cope with periods of feed and water withdrawal, depending on their species, age, physiological state, and pre-transport access to feed and water. Journey conditions can also be an influence, with cold conditions exacerbating the effects of feed withdrawal and hot conditions increasing the risk of dehydration. The facilities containing the animals on the vehicle should minimize the risks of physical injury caused by falls, knocks, bruising, and the protrusion of body parts. Stocking density can also be managed to lessen the influences on animal welfare caused by hot conditions. In a well-ventilated vehicle, it is the stationary periods rather than periods in motion that present the greatest risk of heat stress. The opposite is true for very cold conditions. The land transport of livestock is neither inherently good nor inherently bad for their welfare. Rather, it is the way that it is done, and the management of the risks involved, that determine the level of welfare of the animals involved.     

2021-03期目录

氧化应激是导致人和动物许多疾病发病率和严重程度提高的一个重要诱因。了解氧化应激的发生机制及调节因素,并有针对性地通过营养干预策略阻止或减缓氧化应激的发生,对于优化机体的免疫功能进而预防疾病的发生具有重要的意义。多不饱和脂肪酸代谢产物对炎症反应具有重要的调节作用,这种调节作用多数依赖于其对氧化应激的调控。鉴于此,本文在概述氧化应激发生的基础上,详细阐述了多不饱和脂肪酸代谢产物氧脂对氧化应激的调节作用。     

β-胡萝卜素的主要生理功能及其在畜禽中的应用研究进展

β-胡萝卜素是维生素A的合成前体,在动物体内还发挥其独立于维生素A的抗氧化、抗炎和免疫调节等生理功效。β-胡萝卜素具有促进动物机体生长、降低饲养成本及提高动物产品价值等作用。本文阐述了β-胡萝卜素的理化特性、生产制备来源、体内的吸收代谢途径及其主要的生理功能,总结归纳了近10年来β-胡萝卜素在畜禽养殖中的研究和应用现状,为促进β-胡萝卜素在畜禽养殖中的应用提供参考。     

The importance of the oxidative status of dairy cattle in the periparturient period: revisiting antioxidant supplementation

Dairy cows are especially vulnerable to health disorders during the transition period, when they shift from late pregnancy to the onset of lactation. Diseases at this stage affect not only the animals' well‐being, but also cause a major economic impact in dairy farms, because apart from treatment costs, affected cows will not reach their peak milk‐producing capacity. The overproduction of reactive oxygen species (ROS) leads to oxidative stress, which has been identified as an underlying factor of dysfunctional inflammatory responses. Supplementation with vitamins and trace elements attempts to minimize the harmful consequences of excessive ROS production, thereby trying to improve animals' health status and to reduce disease incidence. However, results regarding the effects of supplementing antioxidants on dairy cows' health and performance have been inconsistent, because in most cases, the antioxidant potential of the animals was not assessed beforehand and the nutritional strategy planned accordingly. Therefore, reviewing the physiological and harmful effects of ROS production, along with the different options available for assessing the redox balance in dairy cattle and some of the key findings of different supplementation trials, could bring one step forward the on‐farm application of determinations of oxidative status for establishing nutritional strategies early enough in the dry period that could improve transition cow health.     

Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals

Polyphenols are secondary plant metabolites which have been shown to exert antioxidative and antiinflamma tory effects in cell culture, rodent and human studies. Based on the fact that conditions of oxidative stress and inflammation are highly relevant in farm animals, polyphenols are considered as promising feed additives in the nutrition of farm animals. However, in contrast to many studies existing with model animals and humans, potential antioxidative and antiinflammatory effects of polyphenols have been less investigated in farm animals so far. This review aims to give an overview about potential antioxidative and antiinflammatory effects in farm animals. The first part of the review highlights the occurrence and the consequences of oxidative stress and inflammation on animal health and performance. The second part of the review deals with bioavailability and metabolism of polyphenols in farm animals. The third and main part of the review presents an overview of the findings from studies which investigated the effects of polyphenols of various plant sources in pigs, poultry and cattle, with particular consideration of effects on the antioxidant system and inflammation.