免疫应激与动物营养

为了提高母猪的繁殖成绩、降低仔猪生产成本 ,养猪生产的一项重大改革是推行仔猪早期断奶。然而大量研究发现 ,仔猪早期断奶后在病原性和非病原性抗原刺激下 ,被激活的单核 /巨噬细胞系统和淋巴细胞 ,释放出一系列被称为细胞介素的化合物。这类化合物主要包括白细胞介素 1(ＩＬ - 1 )、白细胞介素 6(ＩＬ - 6)和肿瘤坏死因子(ＴＮＦ) ,它们不仅能活化免疫系统 ,使动物处于免疫应激状态 ,而且还能通过对靶组织的直接作用或通过改变动物体内某些激素的水平 ,来调节免疫应激过程中动物体内各种养分的代谢 ,使得日粮中的部分养分 ,不再用于动物…     

家禽代谢试验方法研究进展：（二）试验处理重复数、内源养分与粪便收集及单一原料养分代谢率的测定

鉴于目前缺少规范的家禽代谢试验方法的国际标准，本文就此对近年来各国学者开展的家禽代谢试验中所使用的试验动物的处理重复数和每重复安排的动物只数、内源养分与粪便收集方法以及单一原料养分代谢率的测定方法进行综述，旨在为今后国内开展相关试验提供参考。     

饲料营养价值的评定方法

有效养分是指饲料中能被动物吸收并能被利用的那部分养分。通过动物试验测定饲料的有效养分,能反映动物体内部变化和动物对营养物质的需求量。所以在平衡动物饲粮时,根据饲料有效氨基酸、有效矿物质和有效维生素等有效养分的数量配制饲粮更合理,能满足动物对各种营养物质的实际需要量,有利于提高动物的生产力和对饲料的利用效率。     

甘露寡糖对4~6周龄肉仔鸡养分代谢率的影响

甘露寡糖是一种新型绿色饲料添加剂,不仅可以调节动物胃肠道环境,增强动物免疫力,而且可以改善畜禽生产性能。有关研究表明,甘露寡糖在提高家禽及幼龄动物日增重及饲料转化率、降低死亡率、增强动物免疫力等方面有明显作用。本试验通过在日粮中添加不同比例(对照组,0.05%、0.10%、0.15%)的甘露寡糖对白羽肉仔鸡的日粮养分代谢率的影响进行分析,结果表明:添加0.05%的甘露寡糖对肉仔鸡代谢中CP的表观消化率产生显著的差异(P<0.05),其它的代谢养分DM、OM、Ca、P的表观代谢率没产生显著差异。     

半胱胺对奶牛产奶量、乳脂率和饲料转化率的影响

半胱胺又名 β -巯基乙胺 (Cysteamine ,Cs) ,是动物体内辅酶A(CoA)的组成部分 ,为一种非激素类生理活性物质 ,在动物体细胞中可检测到其存在 (Millard ,1 985 )。经多种动物试验研究表明 ,饲料中添加半胱胺能耗竭动物体内的生长抑制激素(SS) ,同时促进机体内源性生长激素 (GH)的合成释放增加 ,随着生长抑制激素浓度的降低 ,消化液分泌增多 ,促进了消化和吸收 ,整体代谢水平提高(王燕玲等 ,1 999)。为探讨饲料中添加半胱胺对奶牛产奶量的影响 ,进行本次试验。1　材料与方法1 1　试验药品　半胱胺 (Cs87)由上海华广达生化实业有限公司…     

铜和维生素A互作关系研究

通过对肉仔鸡体内铜和维生素A代谢的研究,探讨铜与维生素A在代谢中的互作关系。1材料与方法1.1试验设计及营养指标试验采用4×2(铜×维生素A)完全随机试验设计,试验分0～4周龄和5～7周龄2个阶段。除试验因素外,其他指标均参照我国肉仔鸡营养需要。基础日粮中铜含量实测值0～4周龄为23.36mg/kg,5～7周龄为16.00mg/kg。铜以五水硫酸铜粉形态添加,铜的添加量为0,8,150,225mg/kg。维生素A(由北京京牧动物营养中心提供)是以视黄醇乙酸酯粉剂形式添加的,添加量为1500,5000IU/kg。基础日粮组成及养分指标见表1。1.2试验动物及饲养管理选择由山西…     

基于杜泊×小尾寒羊杂交肉羊能量代谢试验与套算法评定燕麦、大麦、小麦、高粱、玉米的代谢能

本试验旨在采用消化代谢试验与套算法评定燕麦、大麦、小麦、高粱、玉米能量饲料在肉羊体内的代谢能(ME),并应用原料概略养分和可消化养分建立有效能的预测模型。选取36只22月龄体重为(52.6±1.4)kg的杜泊×小尾寒羊F_1代杂交去势肉羊,采用完全随机区组设计分为6个处理,包括1个基础饲粮组和5个试验饲粮组。利用消化代谢试验和气体代谢试验并结合套算法计算得到5种能量饲料原料的消化能(DE)和ME,分析原料ME与概略养分、可消化养分之间的相关关系并建立预测模型。结果表明:通过概略养分预测ME的方程为ME(MJ/kg)=19.91+45.763CP(%)-1.013GE(%)+3.247ADF(%)(R~2=0.726,n=30,P0.01);通过可消化养分预测ME的模型为ME(MJ/kg)=-3.113+15.954DOM(%)+5.912DDM(%)+2.281DCP(%)(R2=0.764,n=30,P0.01)。综上所述,本试验中,能量饲料原料概略养分和可消化养分与ME之间存在显著相关,可通过概略养分和可消化养分对能量饲料的ME进行有效预测,且随着预测因子的增加,方程的准确性有所提高。     

饲料中鸡代谢能的测算

代谢能是指饲料中被动物消化吸收供代谢用的养分所含的能量,即从饲料总能减去粪能、尿能及肠胃道产生的甲烷气等即为代谢能。鸡的肠胃道甲烷气体损失很少可以不计。用公式可表示为: 饲料中的代谢能(鸡)(兆焦/千克)=食入饲料燃烧热(兆焦/千克)—粪中的燃烧热(兆焦/千克)—尿中的燃烧热(兆焦/千克)     

大豆异黄酮在家禽生产中的应用研究

大豆异黄酮是大豆生长过程中形成的一类次级代谢产物,具有广泛的生物活性。在家禽的应用研究中发现,日粮中添加适量的大豆异黄酮能显著促进家禽生长、调控机体养分代谢、改善饲料利用率、提高产蛋率、延长产蛋期并具有抗氧化作用,可改善动物产品品质,提高动物免疫机能等作用。     

山羊动-静脉插管技术的应用

我们知道动静脉浓度差测定法是目前定量研究动物吸收代谢产物较好的方法之一。对山羊来说,营养物质的吸收主要在瘤胃和肠道,经瘤胃静脉和肠静脉汇入门静脉。因此,为了研究营养物质在山羊内脏组织(胃肠道和肝脏)中的代谢规律,可在机体不同部位的动-静脉安置血管插管,借助动静脉中养分     

Molecular nutrition: Interaction of nutrients,gene regulations and performances

Nutrition deals with ingestion of foods, digestion, absorption, transport of nutrients, intermediary metabolism, underlying anabolism and catabolism, and excretion of unabsorbed nutrients and metabolites. In addition, nutrition interacts with gene expressions, which are involved in the regulation of animal performances. Our laboratory is concerned with the improvement of animal productions, such as milks, meats and eggs, with molecular nutritional aspects. The present review shows overviews on the nutritional regulation of metabolism, physiological functions and gene expressions to improve animal production in chickens and dairy cows.     

营养对基因表达的调控

随着营养学的深入研究 ,发现日粮中的营养成分可以通过多种途径来调控动物基因的表达 ,从而影响动物机体的代谢过程 ,并最终影响动物的生产。本文从分子基因表达的转录及转录后水平方面对日粮中营养成分的生理作用及在生产上的应用作一简单的概述。     

Regulation Effect of Trace Nutrients and Fat on Manipulation of Animal Gene Expression

Trace nutrients and fat, as important nutrients for animal metabolism, are vital for the growth and development of animals.Importantly, they can regulate gene expression in different ways and levels.The alteration of animal gene expression can affect the animal's nutritional requirements and growth performance by changing the nutrient metabolic pathway and efficiency.With the development of animal nutrition and molecular biology, the mechanism of nutrients regulating gene expression is gradually revealed.In this paper, the effects of trace nutrients and fat regulating gene expression were reviewed aiming to provide a theoretical basis for the determining of animal nutrients requirement more accurately and scientifically.In addition, the application prospects of nutrients regulating gene expression were also discussed.     

微量营养素与脂肪对动物基因表达的调控作用

微量营养素与脂肪作为动物新陈代谢的重要营养物质,只有满足生长发育的营养需要,动物才能平稳的进行各项生命活动,更重要的是它们还作为基因表达的调控物,可以在多途径、多水平对动物基因表达进行调控。动物日粮中营养素含量和类型都会影响动物的基因表达,进而导致动物机体的代谢途径和效率发生改变,最终影响动物的营养需求和生产性能。近年来,随着分子生物技术的发展,营养素对动物基因表达的调控作用及其机制逐渐被揭示出来,新的研究发现纷纷涌现。作者针对微量营养素与脂肪对动物基因表达的调控作用研究进展进行综述,旨在为更准确、更合理地确定动物对营养素的需要量提供理论依据。此外,本综述还对营养素调控基因表达的研究与应用前景作了展望。     

Use of computer simulation to teach a systems approach to metabolism

Use of a systems approach, as embodied in the computer simulation model of metabolism of a dairy cow, Molly (Baldwin, 2005), is ideal for teaching nutrition. This approach allows the overall complexity of the comprehensive system to be broken down into smaller manageable subunits that are easier to visualize. Quantitative interactions among nutrients supplied and metabolic production processes can be observed over extended time periods. Using Molly, undergraduate animal science students are able to observe detailed effects of changing dietary inputs, altering genetic milk production potential, and exogenously manipulating metabolism on metabolism of the whole cow. This paper demonstrates how Molly is used in the classroom to teach a systems approach to nutrition using example simulations. Three simulation examples demonstrate exercises examining effects of recombinant bovine somatotropin administration, dietary protein, and amino acid supplementation and nitrogen efficiency on milk production and cow metabolism. These and similar examples have been used to teach nutrition, metabolism, and lactation to undergraduate students for the past 20 yr.     

饲料中抗营养因子的危害作用及消除方法

抗营养因子是存在于饲料中,阻碍饲料营养成分在体内消化吸收、代谢,导致动物体病变,影响动物生长、繁殖性能的物质。消除抗营养因子是保证饲料营养成分的有效利用、保证动物正常生长发育与健康,降低养殖生产成本的重要措施。为了深入探索饲料抗营养因子消除方法,文章对抗营养因子的抗营养机理和影响后果、消除方法进行了概述。     

Effects of non-starch-polysaccharides in nutrition of monogastric animals

Polysaccharides are widespread biopolymers, which quantitatively represent the most important group of nutrients in botanical feed. In animal nutrition polysaccharides, which cannot be degraded by endogeneous enzymes and therfore reach the colon almost indigested, are summarized as "non-starch-polysaccharides (NSP)". Individual NSP groups have different chemical and physical characteristics, that result in various effects on physiology of intestine and on organism in general. They affect e.g. digesta passage, nutrient resorption, microbial growth and activity, lipid metabolism and immune systeme. The physiological effects lead to conclusion that some polysaccharides are suitable tools in health management of farm animals. However, limitations result from antinutritive effects and from little scientific knowledge about modes of action in vivo.     

Nutrition and the immune system

1. Infectious diseases reduce productivity and diminish animal welfare. 2. Appropriate nutrition may aid in minimising the incidence of diseases by enhancing immunity. 3. An understanding of the pressures imposed by evolution that underlie poultry nutrition as well as those which underlie immunity provides focus to the field of nutritional immunology. Additional understanding is provided by knowing the specific cellular mechanisms by which diet affects immunity, and how these mechanisms pertain to specific nutrients and pathogens. 4. These approaches indicate that higher inclusion rates of all nutrients are not always better and that the traditional ideas of adding a surfeit of specific nutrients to improve immunity does not usually serve us well. 5. Understanding the nuances of nutrition and immunity is important for optimising bird health and productivity, and will be an important contributor towards fulfilling the consumer's conflicting demands for more natural production and better animal welfare.     

日粮营养成分对动物基因表达的调控

本文综述了近年来有关日粮营养成分影响动物基因表达的研究报道。大量证据表明 ,日粮中的常量养分 ,如碳水化合物、蛋白质、脂肪以及某些微量养分均可在一定程度上影响动物基因的表达 ,这种作用可以发生在转录水平 ,也可以发生在转录后水平 ,进而影响机体的整个代谢过程。上述事实使人们试图通过改变日粮养分组成来达到调控动物生产的愿望变得日益可行。