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单胃动物体外消化模拟技术研究进展 总被引：3，自引：0，他引：3
本文从畜禽消化道模拟部位、消化酶的来源和分离已消化养分的方法等几方面对单胃动物体外消化模拟技术进行了归类和总结。并通过对各种体外消化模拟方法的特点、预测饲料养分体内消化率和评定饲料营养价值可靠性等方面的比较分析,总结了各种体外消化模拟技术的优缺点及所存在的问题。同时,针对单胃动物体外消化模拟技术今后的发展方向提出了建议。 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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Thompson A 《Topics in companion animal medicine》2008,23(3):127-132
Every clinician is asked "What should I feed my pet?" Understanding the ingredients in pet food is an important part of making the best recommendation. Pet food can be as simple as one ingredient or as complicated as containing more than 60 ingredients. Pet food and its ingredients are regulated by the Food and Drug Administration and state feed officials. Part of that regulation is the review and definition of ingredients. Existing ingredients change and new ingredients become available so the need for ingredient definitions grows. Ingredients for product formulations are chosen based on their nutrient content, digestibility, palatability, functionality, availability, and cost. As an example, a typical, nutritionally complete dry dog food with 42 ingredients is examined and the ingredients are discussed here. Safe, healthy pet food starts with safe ingredients sourced from well-monitored suppliers. The ultimate goal of both veterinarians and pet food manufacturers is the same--long healthy lives for dogs and cats. 相似文献
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A dynamic mathematical model of the digestion of proteins in the small intestine of pigs was developed. The model integrates current knowledge on the transit of digesta along the small intestine, endogenous secretions, digestion of proteins, and absorption of amino acids into a mechanistic representation of digestion. The main characteristics of the model are the following: the small intestine is divided into several segments of variable length but with equal digesta retention time; the rate of transfer of digesta between segments is based on the progression of myoelectric migration complexes; pancreatic and biliary secretions are poured into the first segment, whereas intestinal secretions enter all intestinal segments; protein hydrolysis is described by first-order equations; and an intestinal absorption capacity is used to estimate absorption of hydrolyzed protein. Simulation results are consistent with observed data, although more information is needed to represent reality more closely. The sensitivity analysis shows that parameters for protein hydrolysis largely determine protein digestibility. The absorption capacity of the small intestine limits the absorption of amino acids at the beginning of a meal and modulates the appearance of amino nitrogen in the portal vein. It also shows that amino acid absorption can be limiting to protein digestibility when large amounts of protein are eaten in a single daily meal. The model is useful in evaluating the dynamics of protein digestion and absorption of feedstuffs. The model can be used in evaluating protein digestion of different feedstuffs and feeding strategies. 相似文献
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《The Journal of Applied Poultry Research》2015,24(3):295-303
Feeding broilers barley-based diets requires special consideration primarily due to effects on increased digesta viscosity and decreased nutrient digestion. Pelleting and glucanase supplementation are commonly performed prior to feeding broilers barley-based diets; however, the interaction of these practices is complex. The objective of this study was to establish a comprehensive evaluation of glucanase efficacy including: degree of processing, activity postpelleting, broiler performance, and digesta viscosity. Treatments were arranged in a 5 (diet formulation) × 2 (processing) factorial in a randomized complete block design with 8 replications/treatment. The 5 diet formulations consisted of positive control (PC), negative control (NC), glucanase A (GA) 125 or 1,000 β-Glu-U/kg feed, and glucanase B (GB) 1,000 β-Glu-U/kg feed. The PC and NC diets differed in metabolizable energy by 150 kcal/kg and enzymes were added to NC formulations. Diets were either fed as unprocessed mash or ground pellets. Diet formulation × processing did not interact for feed intake (FI), FCR, or total tract viscosity (P > 0.05); however, a trend was observed for ending bird weight, demonstrating that for ground pellets, GA 1,000 β-Glu-U/kg feed was improved relative to NC and similar to PC (P = 0.0903). Benefits associated with GB were not of similar magnitude, perhaps in part due to a 50% decrease in activity postpelleting. In addition, GA benefits were not suggested for unprocessed mash. The main effect processing was significant (P < 0.0001) demonstrating that broilers fed ground pellets resulted in greater pen ending bird weight, FI, and bird live weight gain (LWG) compared to birds fed unprocessed mash diets. Evaluations of glucanase should go beyond in vitro activity and include live bird performance using feed that has undergone pelleting. 相似文献
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文章探讨了研究瘤胃淀粉消化率及消化动力学的方法存在的缺陷。淀粉消化位点及该位点的消化率对反刍动物从消化道吸收养分的数量和形式具有重大影响。通过皱胃或十二指肠瘘管收集的食糜样品缺乏代表性,而双相指示剂法也不能完全解决这个问题。原位法被广泛应用于瘤胃淀粉消化速率的测定,但关于从尼龙袋中消失的物质被发酵的假设仍有待商酌。并且,原位法一次函数的假设也受到质疑,说明根据消化动力学参数估计瘤胃淀粉消化率的模型需要完善。体外法以反应体系中淀粉消失率或产气量为基础来评估淀粉消化速率,其重要前提是淀粉消化速率不能受反应体系限制。 相似文献
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本试验旨在研究发酵果渣对杜花二元杂交育肥猪的生长性能、养分表观消化率和饲料通过消化道时长的影响。选取480头80日龄左右、体况相近的杜花二元杂交育肥猪(♂杜洛克猪×♀广东小耳花猪),随机分为试验组和对照组,每组24个重复,每个重复10头猪。对照组饲喂基础日粮,试验组饲喂基础日粮的同时,按照猪生长阶段额外添加5%～20%的发酵果渣,饲养试验全期共5个月。结果显示,小猪阶段(25～60 kg阶段,添加5%～10%的发酵果渣),平均日增重无影响,试验组全价料采食量降低6.12%(P>0.05),料重比降低5.57%(P>0.05);中猪阶段(60～80 kg阶段,添加15%的发酵果渣),试验组平均日增重提高6.52%(P>0.05),全价料采食量降低7.55%(P>0.05,料重比降低12.90%(P<0.05);大猪阶段(80～100 kg阶段,添加20%的发酵果渣),试验组平均日增重提高4.69%(P>0.05),全价料采食量降低9.50%(P>0.05),料重比降低12.20%(P<0.05);试验全期,试验组平均日增重提高2.08%(P>0.05),全价料采食量降低7.47%(P>0.05),料重比降低8.62%(P<0.05)。额外添加发酵果渣能不同程度显著性提高杜花二元杂交育肥猪中后期对粗蛋白质的表观消化率,但对钙和磷的吸收具有降低的趋势。额外添加发酵果渣能缩短杜花二元杂交育肥猪前期饲料通过消化道的时长(P>0.05),但能不同程度延长中后期饲料通过消化道的时长(P>0.05)。本试验结果表明,在杜花二元杂交育肥猪日粮中额外添加适量的发酵果渣能提高生长性能,降低料重比,且可一定程度上延长饲料在育肥中后期猪消化道内的停留时间,促进猪对日粮中粗蛋白质等营养物质的消化吸收。 相似文献
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Effect of fibre content in the diet on the mean retention time in different segments of the digestive tract in growing pigs 总被引：1，自引：0，他引：1
Development of mechanistic models of digestion is a means to account for interactions between different nutrients, and between nutrients and the animal. Although some digestion models for pigs have been proposed, quantitative information concerning the underlying processes is extremely limiting. The aim of this study was to determine the effect of dietary fibre on the transit of the solid and liquid phases of digesta in different segments of the gastro-intestinal tract (GIT) in growing pigs. Six barrows (initial BW 30 kg and fitted with two simple T-cannulas at the proximal duodenum and distal ileum) were used in a double 3 × 3 Latin square design. Pigs were offered diets differing in total dietary fibre content (17, 22 and 27%) at 4 h intervals. A single meal marked with YbO2 and Cr-EDTA was used to determine the passage kinetics of respectively the solid and liquid phases of digesta in different segments of the GIT.
The mean retention time (MRT) averaged 1 h from the mouth to the proximal duodenum (stomach), 4 h from the proximal duodenum to the distal ileum (small intestine), and 35 h from the distal ileum to the faecal excretion (large intestine). Increase in dietary fibre content had no effect on MRT in the stomach, tended to decrease MRT of solid phase in the small intestine (P = 0.07), and decreased MRT of both phases in the large intestine (43 to 29 h, P = 0.06). For all diets, transit of the liquid phase in the large intestine was 4–8 h less than transit of the solid phase. 相似文献
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不同饲料对鱼类消化酶的活性有重要影响,主要包括饲料种类及成分,饲料中不同蛋白质源,饲料不同蛋白质水平,饲料添加剂和饲料加工过程的影响,本文将从上述几个方面进行概述。 相似文献
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M. P. Turski W. Zgrajka A. K. Siwicki P. Paluszkiewicz 《Journal of animal physiology and animal nutrition》2015,99(1):73-78
Kynurenic acid (KYNA) was found to be an antagonist of iontropic glutamate receptors and alpha7 nicotinic acetylcholine receptors. Furthermore, it was documented that KYNA is an agonist of G‐protein coupled GPR35 receptors which are mainly present in the gastrointestinal tract. It was also found that KYNA is present in the gastrointestinal tract and that its concentration gradually increases along it. The origin of KYNA in the gastrointestinal tract is not known. Both might be synthesized from tryptophan in it or absorbed from food and other dietary products. Therefore, the aim of the study was to investigate the concentration of KYNA in animal feed. The results indicate that the highest concentration of KYNA was found in animal feeds intended for livestock. The lower amount of KYNA was detected in animal feeds for fish. Interestingly, the lowest amount of KYNA was found in dog and cat feeds. Furthermore, an analysis of KYNA content in animal food ingredients was conducted. The concentration of KYNA found in one of the ingredients – rapeseed meal – was several times higher in comparison to animal feeds studied. The content of KYNA in the remaining feed ingredients tested was significantly lower. This is the first report on the concentration of KYNA in animal feeds. There is a need for further detailed analysis leading to establishing a set of guidelines for animal feeding. 相似文献
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Yeast cell wall and live yeast products and their combination in broiler diets formulated with weekly ingredient variations 
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下载免费PDF全文 J. Fowler M. Hashim A. Haq C. A. Bailey 《Journal of animal physiology and animal nutrition》2015,99(5):932-937
A 6‐week broiler study was conducted to evaluate whether subjecting the intestinal microflora of broilers to the effect of weekly variations in feed ingredients could be ameliorated by the inclusion of yeast‐derived feed additives: a yeast cell wall extract (YCW), live yeast culture (LY) or their combination (YCW + LY). Recent changes in ingredient prices have motivated producers to formulate diets not necessarily based primarily on corn and soya bean meal. Intestinal microflora in birds can vary significantly based on the ingredient composition of their diet, and the make‐up of the flora can influence overall bird performance. Within the three nutrient phases of this study, birds were fed either a traditional corn–soya ingredient profile or a variable‐ingredient regimen, which had weekly changes in the ingredient composition. There were consistent ameliorative effects of the yeast treatments in both the corn–soya and the variable‐ingredient groups throughout all 6 weeks, with the YCW + LY combination showing a reduced effect when compared to either product fed alone. The effectiveness of YCW and LY on ameliorating the effects of weekly ingredient variations appeared most effective during the starter and grower phases, but was less significant during the sixth week. 相似文献
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棉粕是一种仅次于豆粕的优质植物性蛋白原料,蛋白质含量高,氨基酸种类丰富,但由于含有多种抗营养因子而限制了其在饲料中的应用。利用微生物发酵法处理棉粕可以有效降低其抗营养因子含量,还能提高发酵底物中小分子肽、消化酶、有机酸、益生菌等的含量,从而提高其营养价值。发酵棉粕在动物生产中有较为广泛的应用,在生长育肥猪日粮中使用5%~10%的发酵棉粕替代豆粕,对猪的采食量、日增重和料肉比等指标均没有显著影响,且可降低饲料成本;在鸡日粮中添加5%~15%的发酵棉粕可以提高鸡群免疫力,降低发病率,从而节约用药成本,并可改善鸡肉、鸡蛋的品质;发酵棉粕还可作为反刍动物精料补充料中的蛋白质原料,其所含的营养物质可通过促进瘤胃微生物的生长繁殖从而增加反刍动物对粗饲料的利用率;在水产饲料中用发酵棉粕代替鱼粉和豆粕,不仅可以降低饲料成本及饵料系数,还可以改善水质,提高水产动物体内消化酶含量,从而提高营养物质的消化吸收率。作者综述了发酵棉粕的营养价值,并总结了其在动物生产中的应用研究进展。 相似文献
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食糜在鸡、鸭消化道排空速度的比较研究 总被引：2，自引：0，他引：2
为阐明鸡、鸭对营养物质利用率差异的原因，研究了禽别（公鸡和公鸭）和消化道排空期（4、8、14、24、32、38、48 h）对消化道残留内容物含量的影响，比较食糜在鸡和鸭消化道不同部位的排空速度和排空率。结果表明：鸭排空速度比鸡快,但鸭消化道总残留干物质量和各段消化道残留干物质量都较鸡高；食糜在鸭小肠、直肠及整个消化道的排空率低于鸡的；鸭在强饲后24 h，鸡在32 h其内容物基本排空。在本试验条件下，用Sibbald的TME法测定饲料代谢能和氨基酸真消化率时，鸡的排空期定为32 h，鸭的排空期定为24 h为宜。 相似文献
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M S Kerley A R Kinser J L Firkins G C Fahey L L Berger 《Journal of animal science》1985,61(2):504-513
An experiment examining nutritional effects of dietary corncob particle size was conducted using ruminal-, duodenal- and ileal-cannulated sheep in a 4 X 4 Latin square design. Site of nutrient digestion and digesta flow were the principal criteria evaluated. Analyses of dry matter (DM), N, starch and neutral detergent fiber (NDF) were performed on feed, feces and digesta samples. Chromic oxide-impregnated paper was used as an external marker to estimate digestibilities at different sites along the gastrointestinal tract. Ruminal pH and volatile fatty acid molar proportions were also determined. All diets (74.9% concentrates: 25.1% corncobs) were pelleted and were similar in ingredient composition but varied in corncob particle size (corncob mean particle sizes were 6.5, 5.4, 1.4 or .8 mm). Dietary crude protein levels differed little among treatments. Starch concentration was higher in diets containing the larger corncob particles while NDF, acid detergent fiber (ADF), cellulose and hemicellulose concentrations were lower in diets containing larger particles, suggesting a reaction between starch and fiber moieties during the pelleting process. Starch flow past the duodenum decreased (P less than .05) as dietary corncob particle size decreased. Apparent NDF digestion before the duodenum was highest for sheep fed diets containing 1.4-mm corncobs (P less than .05). Apparent starch digestion in the small intestine decreased (P less than .05) as dietary corncob particle size decreased. A considerable amount of NDF was apparently digested in the small intestine of sheep consuming diets containing 5.4- and .8-mm corncobs. Likewise, a substantial amount of NDF was apparently digested in the large intestine. Few differences in apparent total tract digestibilities were noted.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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