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胃肠道的完整性是决定动物健康与否的关键因素。胃肠道的发育又与饲料的供给有关。胃肠道内腔表面覆盖有黏膜层,以保护胃肠道上皮细胞免遭消化过程和饲料中毒素的破坏。胃肠道中有大量的微生物生长发育,可保护动物免遭病原微生物入侵,并在大肠中发酵未消化的饲料成分。发酵产物是大肠中肠细胞可利用的营养。精氨酸、谷氨酰胺、苏氨酸和组氨酸可用于维持肠道的完整性。 相似文献
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青粗饲料喂猪的原理与实践 总被引：1，自引：1，他引：0
1猪利用青粗饲料的生理基础猪属于单胃、杂食、后消化道发酵动物。猪的大肠全长约4～4.5m,包括盲肠、结肠和直肠。猪的盲肠和前结肠每分种蠕动4～10次,前结肠的逆蠕动把食糜送入盲肠,盲肠的蠕动又把食糜推入结肠,这样食糜就在盲肠和结肠间来回移动,使食糜能在大肠中停留较长时间,增进消化吸收,并为微生物活动创造了良好条件[1][2]。研究表明,猪大肠内的微生物区系包含高活性的反刍纤维素分解菌属和半纤维素分解菌,其中包括琥珀酸生成纤维菌(Fibrobactersuccinogenes)、白瘤胃球菌属(Ruminococcusalbus)、生黄瘤胃球菌(Ruminococcusflavefa… 相似文献
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三、氨基酸的消化率与利用率 猪对蛋白质的消化过程从胃中开始,以氨基酸形式主要在小肠中被吸收利用。未消化的部分进入大肠。这部分蛋白质有些在大肠中主要被发酵,产生氨气、CO_2等,有些被用于合成微生物蛋白质。这些产物很难在大肠中被猪体吸收利用而随粪便排出体外。 相似文献
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本试验旨在用体外法研究不同蛋白质水平对杜长大肥育猪盲肠微生物发酵特性的影响。试验首先采集10头杜长大肥育猪大肠不同区段食糜,测定其主要养分含量,以确定食糜碳水化合物与粗蛋白质添加比例;然后以3头猪盲肠食糜为接种物,酪蛋白水解物为发酵底物进行体外发酵试验。试验组蛋白质水平分别为1.00、1.75和2.50 mg/m L,每组4个重复,37℃体外发酵24 h,测定产气量、p H以及氨态氮、菌体蛋白和短链脂肪酸含量。结果显示:1)猪盲肠食糜各养分含量在一定范围内变化,碳水化合物与粗蛋白质含量比范围为1.86~3.24,平均值为2.66。2)随着蛋白质水平的升高,产气量显著增加(P0.05),氨态氮、总短链脂肪酸、支链脂肪酸、乙酸、丁酸、戊酸、异丁酸和异戊酸含量显著升高(P0.05)。以上结果表明:猪大肠食糜中碳水化合物与粗蛋白质含量比在一定范围内变化,而盲肠微生物对蛋白质的发酵能力随底物蛋白质水平的升高而增强。 相似文献
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《河南畜牧兽医(综合版)》2001,22(11)
猪后肠对纤维的降解猪的小肠和大肠不分泌降解纤维的酶，纤维能被产生纤维酶、半纤维素酶及其它酶的一些微生物所降解，这些微生物在反刍动物和非反刍动物的盲肠和结肠里大量存在。与瘤胃微生物相仿，猪大肠中类杆菌属细菌和瘤胃球菌属细菌是主要的纤维分解菌。饲料纤在大肠中停留２０～４０小时小肠２～１６小时，在此期间它被部分分解为挥发性脂肪酸ＶＦＡ，包括醋酸盐、丙酸盐、丁酸盐以及甲烷、氧气和二氧化碳等气体。ＶＦＡ很快被后肠吸收，并提供肥育猪和成年猪３０％的维持能量需求，因此，它对体内总能利用是相当重要的。ＰＳＥ猪肉… 相似文献
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长期以来 ,人们对日粮纤维持否定态度 ,认为不仅没有营养价值 ,而且还会降低整个饲料的营养价值。自从人的医学上发现膳食纤维与一些“文明病”(血管病、直肠癌、肥胖等 )有着某种联系后 ,膳食纤维随之成为医学的研究热点 ,同时也带动了动物营养学者对日粮纤维的研究。本文主要阐述猪利用日粮纤维的研究状况。1 猪利用日粮纤维的生理基础1 1 猪生物学特性 猪作为杂食动物 ,采食量较大 ,消化道长 ,消化速度较快 ,能部分地利用植物性饲料。我国传统养猪业比较粗放 ,因此我国的猪一般都具有食性广、耐粗饲的特点。1 2 猪大肠内的微生物区… 相似文献
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关于反刍动物瘤胃及猪大肠内的微生物消化 总被引：1，自引：0，他引：1
<正> 栖居于胃肠道内的微生物对草食动物的消化和营养具有十分重要的意义。非反刍单胃动物(兔、马、猪等)的微生物消化,主要在大肠内进行。反刍动物(牛、羊等)除大肠外,复胃的第一、二室(瘤网胃),则是微生物对饲料进行消化代谢的主要场所。研究反刍动物及猪的微生物消化,不但对饲料合理利用,提高乳、肉、毛、役的生产性能有重要意义,在比较生理学方面也可提供有价值的资料。本文就我们近年研究结果作一简要介绍。 相似文献
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在动物的消化追酶可以促进饲料的消化。饲料中的淀粉、蛋白质和脂类,都容易被动物自身的消化系统分解。然而,许多其它成分,如植物细胞壁中的多聚糖,仅能部分地被单胃动物,如猪和禽所消化。反刍动物可惜助其瘤胃中的微生物发酵分解这些细胞壁多聚糖,而单胃动物对这些多聚糖的发酵仅局限于大肠,因此发酵很少。 相似文献
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Histology and Mucin Histochemistry of The Digestive Tract of Yellow Catfish, Pelteobagrus fulvidraco
The histology and characteristics of mucins secreted by epithelial mucous cells of the digestive tract in yellow catfish, Pelteobagrus fulvidraco were investigated using light microscope and transmission electron microscope. The digestive tract was divided into a pharynx, oesophagus, U-shaped stomach (with a cardiac, fundic and pyloric part) and intestine, composed of anterior intestine, middle intestine and posterior intestine, which consisted of a mucosa (epithelial layer), lamina propria-submucosa, muscularis and serosa. A large number of isolated longitudinal striated muscular bundles were present in the lamina propria-submucosa of pharynx. Goblet cells were observed throughout the digestive tract, except in the stomach. In the cardiac and fundic stomach, a plenty of gastric glands were observed, whereas they were absent in the pyloric part. Numerous mitochondria and endoplasmic reticulum were observed in the columnar epithelial cells of the intestine, especially of the anterior part. The epithelial mucous cells contained neutral or other two mixtures of acid and neutral mucins, the first being the most common. The neutral mucin was the only type of mucins in the stomach, anterior intestine and middle intestine. The results of this study will be helpful for understanding the digestive physiology and diagnosing some gastrointestinal diseases in yellow catfish. 相似文献
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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. 相似文献
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W G Pond 《Journal of animal science》1987,65(2):497-499
There is continued incentive for the development of alternative feed resources for use in swine production. The availability of distillery by-products may be expected to increase as the use of corn and cereal grains for ethanol production expands. The acceptability of distillery by-products, milling by-products, forages and other fibrous feeds as energy sources for swine depends on such factors as cell wall content of the plant, degree of microbial fermentation in the large intestine, and extent of absorption and utilization of the volatile fatty acids produced. Physiological effects of dietary fiber, including effects on gastric emptying, rate of transit of digesta, gut motility, digestive secretions, and absorption and utilization of breakdown products need quantification. Limited evidence suggests that there are genetic differences in the response of pigs to dietary fiber and in their ability to utilize it as an energy source. Recombinant DNA technology offers the possibility of cloning cellulase genes from microorganisms for application in swine feeding programs. The extent to which biotechnology will be applied in swine feeding will depend ultimately on the economic incentive for developmental effort and on unknown biological limitations of the pig and its gastrointestinal microbial ecosystem. 相似文献
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Scott Ford 《Journal of Exotic Pet Medicine》2010,19(2):140-150
Birds of prey have developed talons, a hooked beak, and a tongue and oral cavity replete with pronounced hooks and papillae for prehending large boluses of food. The size of the proventriculus in relation to the ventriculus and weak musculature of the ventriculus, combined with an extremely acidic luminal pH, are consistent with a gastric digestive physiology maximized for protein digestion. The pyloric sphincter retains indigestible matter in the stomach, which is later compressed into a pellet and egested. The ventriculus, pylorus, pancreas, and an elongated duodenum coordinate to maximize neutralization of acidic peptic juices and increase the efficiency of digestion and absorption. Raptors are susceptible to a variety of infectious and noninfectious diseases that affect the digestive tract. Diagnostic testing and treatment recommendations for raptor intestinal disease conditions are discussed in this article. 相似文献
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肠道是肉鸡重要的消化、内分泌及免疫器官，肠道健康主要依赖于营养物质、微生物菌群和肠道黏膜之间的动态平衡。肠道消化吸收功能与肠黏膜上皮细胞的生长及肠道形态结构的完整性直接相关。研究表明，丁酸钠作为能量来源，可刺激肉鸡肠道上皮细胞增殖并改善肠道黏膜形态，促进绒毛生长和肠道组织发育。丁酸钠通过肠道游离脂肪酸受体FFAR2和FFAR3介导肠道内分泌细胞分泌多种激素，促进胃肠黏膜的发育，刺激胃和胰腺分泌消化酶，促进养分消化吸收。丁酸钠是肠道稳态的重要调节因子，可刺激黏蛋白的产生，增加黏液层厚度，降低结肠上皮的通透性，维持肠道完整性和黏膜屏障功能。丁酸钠促进宿主防御肽（HPDs）的合成，抑制肠道内有害菌的增殖，降低内毒素对肠黏膜上皮细胞的损伤。丁酸钠通过抑制NF-κB激酶（IKK）下调促炎症途径，抑制NF-κB的活化，预防肠黏膜炎症发生，进而促进消化吸收和保护肠道健康。综上，丁酸钠具有肠道保护和抗菌作用，可增强肠道完整性，促进营养物质的消化吸收，提高免疫力和抗病力。在饲料工业禁抗的背景下，对抗生素替代品丁酸钠的研究和应用非常重要，作者就丁酸钠对肠道功能的作用机制进行重点阐述，以期为其在肉鸡饲料中替代抗生素提供科学依据。 相似文献
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A. Wilfart Y. Jaguelin-Peyraud H. Simmins J. Noblet J. van Milgen L. Montagne 《Livestock Science》2007,109(1-3):179-181
Nutritional feed values are currently based on aggregate criteria such as the ileal or faecal digestibility. Digestibility is the result of two competing processes: digestion and passage. In order to develop mechanistic models of digestion to be used for feed evaluation, both processes have to be quantified. The aim of this study was to determine the hydrolysis kinetics of main constituents (organic matter, N and starch) in wheat, barley, wheat bran and soybean meal, using a three-step, enzymatic in vitro method mimicking digestion in the stomach, small and large intestine of pigs. Kinetics of hydrolysis (i.e. solubilisation of feed constituents) was modelled using an exponential segmented model estimating the extent and rate of digestion in each digestive segment. Digestion of organic matter of soybean meal occurred mainly in the stomach (67% vs. < 30% for other feeds) resulting from an efficient protein hydrolysis at this site. Organic matter of cereals was mainly digested in the small intestine (55%), as a result of starch digestion. Fractional digestion rates of organic matter were higher in the stomach than in the small intestine (20–35 vs. 2–15%/min). The potential digestibility of organic matter was nearly 87% for wheat and soybean meal, 78% for barley and 61% for wheat bran, which correspond to typical in vivo digestibility values. The results of the present study allow characterising different feeds with the objective to model the digestion process in pigs. 相似文献
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欧洲猪生产中抗菌饲料添加剂的禁用及对猪胃肠道微生物发酵的有益调控的研究 ,促进了非消化性寡糖的研究。非消化性寡糖 ,作为化学益生素最显著的作用就是对有益菌 ,如双歧杆菌的特殊的刺激作用 ,并通过竞争性排斥病源微生物如大肠杆菌的生长 ,抑制有害菌的作用 ,从而有助于保持胃肠道合适的菌丛。然而 ,猪日粮中包含的特异性非消化性寡糖对微生物生态系统、消化过程及动物的生产性能的作用存在着争议。由于大多数非消化性寡糖在胃和小肠中快速的发酵速率 ,因此上段消化道的糖分解活力不能在整个消化道中维持。若使用在整个胃肠道部分包括大肠能够发酵的非消化性寡糖的复合物可延长化学益生的作用 ,并且证明其作为饲料添加剂在猪饲料中的使用是有效的 相似文献