猪的膳食纤维营养与应用概述

膳食纤维对不同生长阶段猪营养作用表现不同。日粮中添加膳食纤维有助于仔猪肠道发育并维持肠道健康和微生态平衡,减少仔猪断奶应激,缓解仔猪断奶腹泻。肥育猪日粮中添加膳食纤维,可增强后肠发酵,减少粪氮的排放量,降低环境污染,也可节约常规原料。妊娠母猪日粮中添加膳食纤维可减少限饲应激和便秘的发生,并且能改善母猪的繁殖性能,促进哺乳仔猪生长。本文主要综述了膳食纤维的定义、理化性质、分析体系及其在猪营养上的应用,以期为实际生产提供一定的指导意义。     

Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.     

日粮纤维在猪日粮中的应用研究进展

日粮纤维，一方面会降低养殖成本及养分利用率和猪只生长性能；另一方面，可以通过肠道微生物发酵与抑制病原菌定植提高猪只肠道健康水平。高日粮纤维猪只日粮的负面影响受纤维来源、类型和添加水平影响，而合理使用日粮纤维能改善仔猪肠道健康并提高母猪繁殖性能；添加纤维降解酶可以缓解日粮纤维的抗营养作用，以保证其对仔猪肠道健康的改善作用。文章就日粮纤维类型、使用方法及对猪只营养、肠道健康的影响进行了综述，以期为日粮纤维的有效利用提高养殖生产效益提供参考和依据。     

Strategies to improve fiber utilization in swine

Application of feed processing methods and use of exogenous feed additives in an effort to improve nutrient digestibility of plant-based feed ingredients for swine has been studied for decades. The following review will discuss several of these topics, including: fiber characterization, impact of dietary fiber on gastrointestinal physiology, energy, and nutrient digestibility, mechanical processing of feed on fiber and energy digestibility, and the use of exogenous enzymes in diets fed to growing pigs. Taken together, the diversity and concentration of chemical characteristics that exists among plant-based feed ingredients, as well as interactions among constituents within feed ingredients and diets, suggests that improvements in nutrient digestibility and pig performance from mechanical processing or adding exogenous enzymes to diets fed to swine depends on a better understanding of these characteristics, but also relating enzyme activity to targeted substrates. It may be that an enzyme must not only match a target substrate(s), but there may also need to be a ^′cocktail^′ of enzymes to effectively breakdown the complex matrixes of fibrous carbohydrates, such that the negative impact of these compounds on nutrient digestibility or voluntary feed intake are alleviated. With the inverse relationship between fiber content and energy digestibility being well described for several feed ingredients, it is only logical that development of processing techniques or enzymes that degrade fiber, and thereby improve energy digestibility or voluntary feed intake, will be both metabolically and economically beneficial to pork production.     

Supplement strategies for ruminants and management of feeding to maximize utilization of roughages

Principles of supplementation are discussed in respect of both, their positive and negative effects on roughage digestion and utilization by ruminants. It is pointed out that negative effects mainly occur when excessively processed concentrate is given in large quantities two times per day. This lowers rumen pH which in turn depresses cellulose digestion and intake of cellulosic feeds, leading to problems of acidosis and secondary ketosis due to off-feed conditions. To a large extent, such problems can be overcome by limited processing and feeding the concentrate mixed with the roughage. Supplements can also have positive effects by alleviating deficiencies such as nitrogen or by providing easily fermentable fiber to increase microbes for attachment to roughages. Supplements can increase microbial protein production and undegraded protein supply. It is emphasized that proper use and management of supplements can make the difference between profit and loss for small farmers.     

日粮纤维对猪肠道微生物影响的研究进展

肠道微生物不仅为宿主提供营养物质,也有利于维持肠道微生态的平衡,对保证肠道的健康发育至关重要。日粮纤维是肠道微生物发酵的底物之一,能够改善肠道微生物菌群结构。本文从日粮纤维对猪肠道微生物的功效及影响猪肠道微生物利用日粮纤维的因素展开综述,为日粮纤维在生猪生产实践及研究提供一定理论依据。     

Comparative response of swine and rats to high-fiber or high-protein diets

Twenty-four growing swine and 24 growing rats were fed high-protein (34%) diets on an ad libitum basis to determine their effects on body weight, carcass characteristics, intestinal microbiological profile and visceral organ weights. High dietary fiber reduced body weight gain and gain:feed ratio in both swine and rats and decreased body fatness in swine; it increased relative kidney weight (percentage of body weight) in both swine and rats and decreased relative liver weight in rats but increased it in swine. Absolute weights of stomach and large intestine were unaffected by high fiber in either species, but relative weight of small and large intestine was increased in swine and relative weight of stomach was increased in rats. High dietary protein increased absolute and relative weights of kidneys in both species and increased relative liver in swine but not in rats. Absolute weight of large intestine was increased by high dietary protein in rats and tended to be increased in swine; relative large intestine weight was increased in both species. The microbial profile of large intestinal contents of rats showed no effect of diet on Enterobacteriaceae, Campylobacter, Salmonella or total anaerobes and cellulolytic organisms, but coliforms were higher in rats fed high fiber or high protein than in controls. We conclude that dietary levels of fiber and protein influence growth of specific segments of the gastrointestinal tract of growing rats and swine, probably by different mechanisms of action.     

饲粮纤维影响猪肠道健康的研究进展

肠道健康包括有效的营养物质吸收、稳定的肠道微生物群落及健全的免疫功能等多个方面。肠道的健康状况决定了动物的健康状况。肠道健康取决于饲粮、肠道黏膜和肠道微生物群落3个主要方面。饲粮纤维是由纤维素、半纤维素、果胶和木质素等组成的成分和结构复杂的混合物,具有改善肠道营养物质吸收、降低肠道环境p H、改变有益菌与潜在致病菌比例、优化肠道微生物群落组成及加强黏膜屏障作用等功能。来源不同和理化性质相异的饲粮纤维对肠道健康的影响及作用机理并不一致。本文就饲粮纤维的分类、理化性质及其对肠道健康影响的研究进展进行综述,以促进饲粮纤维在猪饲粮生产上的进一步广泛合理利用。     

猪对饲料纤维的利用

综述纤维的一般概念、对猪的营养作用、猪后肠微生物对纤维的发酵作用、影响猪对饲料纤维利用的因素和纤维在猪日粮中的适宜水平     

饲粮纤维对家禽的营养调控研究进展

纤维曾被视为家禽饲粮所含的一种抗营养因子,但适量的饲粮纤维可有效改善家禽的营养与健康。饲粮纤维成分复杂,不同纤维源的营养功能与作用机制不尽相同。本文介绍饲粮纤维的概念与性质,探讨其对家禽消化生理、肠道健康及生产的影响,阐释其调控家禽营养的机制,为其在家禽生产中高效利用提供科学依据。     

木薯及其副产品的营养价值及在动物生产中的应用

木薯耐干旱、耐贫瘠且易管理，其茎叶、块根及工业副产物营养物质含量较高，是一种优质的非常规饲料。木薯叶粗蛋白质、粗脂肪、灰分含量较高，含有丰富的钙、铁、锌、锰。木薯块根是很好的能量来源，其粗蛋白质、粗脂肪、矿物质、维生素含量低于木薯叶。木薯渣主要由木薯的外皮、破碎细胞壁等组成，粗蛋白质含量很低，粗纤维、中性洗涤纤维、酸性洗涤纤维含量较高，矿物质、氨基酸丰富，但钙、磷、氨基酸不平衡。木薯品种、生长条件、收割方式、收获时间、加工工艺等均会影响木薯及其副产品营养物质的含量。木薯中含有氰化物、单宁及植酸等抗营养因子，其中氰化物是限制木薯应用的最主要因素，其可结合细胞色素C氧化酶，阻断线粒体电子传递链，抑制有氧呼吸，导致中枢神经系统抑制和死亡。单宁、植酸与蛋白质结合生成络合物，阻碍营养物质的消化吸收，可通过水煮、烘烤、干燥等物理化学方法，以及发酵、育种等手段对木薯进行脱毒。研究表明，木薯及其副产品可广泛应用于动物生产中，对动物生长性能、肉品质无不良影响。开发与利用非常规饲料有利于缓解饲料资源紧张，降低养殖成本。作者详细介绍了木薯及其副产品的营养价值、抗营养因子及其脱毒方法以及其在动物生产上的应用，以期为木薯在畜禽养殖中的综合利用提供一定的参考。     

Fermentation characteristics of resistant starch,arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review

Dietary fibers (DF) contain an abundant amount of energy, although the mammalian genome does not encode most of the enzymes required to degrade them. However, a mutual dependence is developed between the host and symbiotic microbes, which has the potential to extract the energy present in these DF. Dietary fibers escape digestion in the foregut and are fermented in the hindgut, producing short-chain fatty acids (SCFA) that alter the microbial ecology in the gastrointestinal tract (GIT) of pigs. Most of the carbohydrates are fermented in the proximal part, allowing protein fermentation in the distal part, resulting in colonic diseases. The structures of resistant starch (RS), arabinoxylan (AX), and β-glucan (βG) are complex; hence, makes their way into the hindgut where these are fermented and provide energy substrates for the colonic epithelial cells. Different microbes have different preferences of binding to different substrates. The RS, AX and βG act as a unique substrate for the microbes and modify the relative composition of the gut microbial community. The granule dimension and surface area of each substrate are different, which influences the penetration capacity of microbes. Arabinose and xylan are 2 different hemicelluloses, but arabinose is substituted on the xylan backbone and occurs in the form of AX. Fermentation of xylan produces butyrate primarily in the small intestine, whereas arabinose produces butyrate in the large intestine. Types of RS and forms of βG also exert beneficial effects by producing different metabolites and modulating the intestinal microbiota. Therefore, it is important to have information of different types of RS, AX and βG and their roles in microbial modulation to get the optimum benefits of fiber fermentation in the gut. This review provides relevant information on the similarities and differences that exist in the way RS, AX, and βG are fermented, and their positive and negative effects on SCFA production and gut microbial ecology of pigs. These insights will help nutritionists to develop dietary strategies that can modulate specific SCFA production and promote beneficial microbiota in the GIT of swine.     

Copper in the nutrition of pigs and rabbits: A reviewLe cuivre dans la nutrition des porcs et des lapins: Une mise au pointKupfer in der ernährung von schweinen und kaninchen: Eine übersicht

Copper (Cu) is needed by pigs and rabbits to prevent microcytic hypochromic anaemia, dermatosis and bone marrow problems and to maintain the integrity of the cardiovascular system. Cu also performs metabolic functions as a constituent of several enzymes systems in the body. Actual Cu deficiency is rare in pigs and rabbits fed balanced diets; however, in adequate Cu intake may arise under certain dietary conditions. While Cu levels higher than those required to satisfy the body needs may be dangerous for some livestock species, pigs and rabbits can tolerate and often respond to dietary Cu levels of up to 250 ppm (about 50 times higher than their requirements). This response is shown by improved growth and feed utilization. Levels approaching 500 ppm in pig diet will result in poor growth, toxicity and, in some cases, death. The rabbit, on the other hand, has a higher tolerance for Cu and will not show any toxicosis at such high Cu levels. Dietary conditions, including mineral balance, level and type of protein, as well as some energy sources like cassava meal affect Cu utilization in both species. In the rabbit, dietary ascorbic acid interferes with Cu utilization. Some implications of Cu feeding on meat quality are discussed. Suggestions are also made for further investigations on the use of Cu for efficient production of both pigs and rabbits.     

鹅消化利用纤维的生理特点及影响因素

鹅属草食性水禽,其对纤维的消化利用过程与鸡、鸭等有较大区别。长期以来,鹅日粮纤维的使用缺乏统一的饲料营养标准,养殖从业人员对鹅消化利用纤维的生理特点认识不全面。文章旨在详细介绍鹅消化利用纤维的主要生理特点,并从纤维来源、营养水平、鹅品种、日龄等方面综述其对鹅纤维消化利用的影响,为生产中纤维饲料原料的合理使用提供技术支持。     

干酒糟及其可溶物的营养价值及其在猪生产上的应用

干酒糟及其可溶物(DDGS)是乙醇生产工业副产物,随着生物能源的应用增加,DDGS产量上升。DDGS最先用于反刍动物生产中,近年来,也有很多报道将DDGS用于猪、鸡等单胃动物生产行业。本文从DDGS的生产工艺、营养组成、对猪的营养价值及其在猪生产上的应用现状以及改进措施等几个方面对近十年来国外学者在DDGS上的研究进行了综述。虽然DDGS能替代部分豆粕和玉米用于猪生产中,但由于其质量的不稳定、蛋白质品质的低下和粗纤维含量过高影响了其大量使用。通过过筛、发酵、加酶、不同原料组合使用等方法能扩大并提高DDGS在养殖行业的应用。     

Phytate and phytase in fish nutrition

Phytate formed during maturation of plant seeds and grains is a common constituent of plant-derived fish feed. Phytate-bound phosphorus (P) is not available to gastric or agastric fish. A major concern about the presence of phytate in the aquafeed is its negative effect on growth performance, nutrient and energy utilization, and mineral uptake. Bound phytate-P, can be effectively converted to available-P by phytase. During the last decade, phytase has been used by aqua feed industries to enhance the growth performance, nutrient utilization and bioavailability of macro and micro minerals in fish and also to reduce the P pollution into the aquatic environment. Phytase activity is highly dependent on the pH of the fish gut. Unlike mammals, fish are either gastric or agastric, and hence, the action of dietary phytase varies from species to species. In comparison to poultry and swine production, the use of phytase in fish feed is still in an unproven stage. This review discusses effects of phytate on fish, dephytinisation processes, phytase and pathway for phytate degradation, phytase production systems, mode of phytase application, bioefficacy of phytase, effects of phytase on growth performance, nutrient utilization and aquatic environment pollution, and optimum dosage of phytase in fish diets.     

Biochemical and physiological bases for utilization of dietary amino acids by young Pigs

Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all "nutritionally nonessential amino acids" (NEAA) to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules (e.g., nitric oxide, carbon monoxide, and hydrogen sulfide). Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the roles and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.     

Evaluation of corn fiber, cottonseed hulls, oat hulls and soybean hulls as roughage sources for ruminants

An in situ trial (randomized complete block design) using cows, and a site and extent of digestion trial (Latin square design) using sheep were conducted to study the potential of corn fiber (CF), cottonseed hulls (CSH), oat hulls (OH) and soybean hulls (SH) as roughage sources for ruminants. Two feedlot trials with steers and one with lambs (completely randomized design with factorial arrangements of treatments) were conducted to study the potential of CF and SH as energy supplements relative to corn. In situ rate of ruminal dry matter (DM) disappearance (3 to 36 h) and extent of DM disappearance (36 h) indicated that CF and SH were more fermentable in the rumen compared with OH or CSH, with SH being the most fermentable. Total tract digestibilities of DM, organic matter (OM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were above 70% for sheep fed CF and SH diets, and were 50% or less for sheep fed OH and CSH diets. A ranking of by-products in terms of nutritive value followed the trend: CF greater than SH greater than OH greater than CSH. Lamb feedlot trial data showed that CF was of similar nutritive value to corn and of higher nutritive value than SH at the 50% level of supplementation. Corn-fed lambs responded better than CF- or SH-fed lambs at the 70% level of supplementation. Data from steer feedlot trials showed that CF was of similar quality to corn and of higher quality than SH. Dramatic differences exist in by-product feed utilization by ruminants. All by-products tested appeared to have some usefulness as dietary components.     

Dietary fiber and microbiota interaction regulates sow metabolism and reproductive performance

Dietary fiber is a critical nutrient in sow diet and has attracted interest of animal nutritionists for many years. In addition to increase sows’ satiety, dietary fiber has been found to involve in the regulation of multiple biological functions in the sow production. The interaction of dietary fiber and gut microbes can produce bioactive metabolites, which are of great significance to sows'' metabolism and reproductive performance. This article reviewed the interaction between dietary fiber and gut microbes in regulating sows'' gut microbial diversity, intestinal immune system, lactation, and production performance, with the aim to provide a new strategy for the use of dietary fiber in sow diets.     

干酒糟及可溶物（DDGS）在猪饲料中利用的探讨

乙醇工业生产工艺的革新,引起了乙醇工业发酵过程的副产物（或共生产品）干酒糟及可溶物（DDGS）的营养物质含量发生了变化。粗蛋白质（25％～30％）和粗脂肪（10％～12％）含量的升高,提高了DDGS在猪饲料中作为蛋白质和能量补充资源的饲用价值。此外,DDGS的有效磷和对生长发育和生产有益的有效因子的含量也有改进。本文对在猪饲料中利用这种副产物进行了探讨。