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1、水分无氮浸出物图图 概略养分与饲料组成之间的关系概略养分与饲料组成之间的关系 饲料 干物质干物质无机物（粗灰分或矿物质）有机物含氮化合物（粗蛋白质）无氮化合物乙醚浸出物（粗脂肪）碳水化合物粗纤维四、养分含量的表示方法四、养分含量的表示方法 某饲料新鲜基础含某饲料新鲜基础含CP5%CP5%，水分水分75%75%，求饲，求饲料风干基础（含水料风干基础（含水10%10%）下含蛋白质多少？）下含蛋白质多少？ 四、养分含量的表示方法四、养分含量的表示方法 某饲料新鲜基础含某饲料新鲜基础含CP5%CP5%，水分水分75%75%，求饲，求饲料风干基础（含水料风干基础（含水10%10%）下含蛋白质多少？）下含
2、蛋白质多少？ 设为设为x x，则则x90%=5%25%x90%=5%25%x=x=（5%5%90%90%）25%=18%25%=18%DIGESTION消化消化Anatomy and Function of the Gastrointestinal Tract胃肠道解剖和功能胃肠道解剖和功能Key concepts about the digestive system and digestionLarge complex molecules, like proteins, polysaccharides, and triglycerides must be broken down into t
3、heir simplest part before they are absorbed into the blood or lymph. This is the job of the digestive system 大复杂分子如蛋白质、多糖和甘油三酯在吸收入血或淋巴之前必须分解成最简单成分。这是消化系统的工作。Digestion requires enzymes that break specific types of chemical bonds. If an enzyme is not present, digestion of that molecule does not occur
4、消化需要酶。There are two sources of digestive enzymes: those made by the animal (digest soluble CHO, protein and lipids) and those made by microbes during fermentation (digest soluble CHO, protein and lipids and fiber). 消化酶有两个来源： 一是来自动物本身（消化可溶性碳水化合物、蛋白质和脂类）； 二是来自于微生物（消化可溶性碳水化合物、蛋白质和脂类及纤维）Key concepts abo
5、ut the digestive system and digestionFor optimum utilization, digestion or fermentation needs to occur either in front of, or inside the part of digestive system that absorbs the final products produced by digestion 为优化利用，消化或发酵需要发生在消化系统吸收消化产物之前或当中。为优化利用，消化或发酵需要发生在消化系统吸收消化产物之前或当中。Fermentation improve
6、s overall utilization of feeds for all animals 发酵改善所有动物饲料充分利用。发酵改善所有动物饲料充分利用。Differences in size of some parts of the digestive system and location of fermentation within the digestive system dictate the types of feeds animals can utilize and the proper means of feeding. 由于消化系统尺寸大小不同或发酵位置不同决定动物能利用饲料
7、的类型由于消化系统尺寸大小不同或发酵位置不同决定动物能利用饲料的类型及适宜的饲喂方法。及适宜的饲喂方法。为什么胃没有被消化了！为什么胃没有被消化了！Gastrointestinal TractnComplex physiologically and anatomicallynExtends from mouth to anusnFunctionsqDigestionqAbsorptionqProtect body from:qRemove undigested material and wastesqImmunological functionqMetabolismqEndocrine fun
8、ctions (Hormones)nSite of fermentation (symbiosis)咽盲肠十二指肠肝脏胆囊唾液腺舌牙齿幽门括约肌胃食道唾液腺肛门阑尾会厌胰腺大肠小肠直肠RuminantCattle, Sheep, Goats反刍动物反刍动物-牛，绵羊，山羊牛，绵羊，山羊Nonruminants 非反刍动物非反刍动物网胃小结肠盲肠小肠牙齿食道胃大结肠食道瘤胃皱胃小肠直肠胃小肠小肠食道肝脏盲肠结肠瓣胃Simplified Digestive SystemsMouth and Saliva嘴和唾液嘴和唾液nFunction of the mouth 嘴的功能嘴的功能qTake in
9、food 采食采食nPrehensile structureqHorses-lips 马马-唇唇qCattle-tongue 牛牛-牙齿牙齿qPigs-lips 猪猪-唇唇qSheep-lips 绵羊绵羊-唇唇nTaste accept or reject food 品尝品尝nChewing 嚼嚼qReduces particle size which improves digestibilityqStimulates saliva flownMix digesta with saliva 混合混合Pig猪猪Horse马马Sheep绵羊绵羊Cattle牛牛臼齿臼齿切割和犬齿切割和犬齿牙床牙床G
10、rinding grain to reduce particle size锤片转子锤片转子出料口出料口磨的档板磨的档板 Mouth and SalivanFunction of saliva唾液的功能唾液的功能qLubricate food to allow swallowing and mixing of food in stomach of nonruminants润滑食物便于吞咽和食物在反刍动物胃里混合润滑食物便于吞咽和食物在反刍动物胃里混合qInitiate enzymatic digestion (amylase) of starch开始淀粉酶解（淀粉酶）开始淀粉酶解（淀粉酶）qPr
11、oduce buffer to counteract acid in stomach产生缓冲液中和胃酸产生缓冲液中和胃酸Mouth and SalivaComposition of saliva 唾液成分唾液成分qWater水水qInorganic components无机成分无机成分nUsed to supply minerals to digesta andbuffers to regulate pHqOrganic components有机成分有机成分nNeeded for digestive functionsqUreaqEnzymesqMucoproteins黏蛋白黏蛋白Esopha
12、gus食道食道nMuscular tube肌管肌管qExtends from pharynx to cardia of stomach 咽至贲门咽至贲门nStriated muscle 纹状肌纹状肌which changes to smooth muscle平滑肌平滑肌qEsophagus of dogs and ruminants have striated muscle throughoutEsophagusnExtended by reticular groove (esophageal groove) in young ruminantsqAllows passage of milk
13、from esophagus directly into omasum during nursing奶至皱胃奶至皱胃qThis prevents milk from entering the rumen, where it would be fermented resulting in a loss of nutrients 防止奶流入瘤胃防止奶流入瘤胃Stomach胃胃n(Glandular or True) Stomach腺胃或真胃腺胃或真胃nFunctions of true stomach真胃的功能真胃的功能qMixing of food 混合混合qHold food for grad
14、ual release into small intestine食物进入小肠食物进入小肠qProduction of HCl and pepsinogen盐酸和胃蛋白酶原盐酸和胃蛋白酶原qAbsorption of alcohol, aspirin, volatile fatty acids (ruminants), and various other compounds. 吸收乙醇、阿司匹林、挥发性脂吸收乙醇、阿司匹林、挥发性脂肪酸和其它不同化合物。肪酸和其它不同化合物。qThere is no absorption of monosaccharides, amino acids, or l
15、ong chain fatty acids in the stomach. 胃不吸收单糖、氨基酸或者长脂肪酸链。胃不吸收单糖、氨基酸或者长脂肪酸链。StomachnSecretions of true stomach真胃分泌作用真胃分泌作用qHClnDenatures protein-breaks intermolecular bondsnKills most bacteria present in foodstuffsnActivates pepsinogennRuptures starch granules破裂淀粉颗粒破裂淀粉颗粒qPepsinogen胃蛋白酶原胃蛋白酶原nHCl conv
16、erts pepsinogen to pepsin the active enzyme胃蛋白酶原胃蛋白酶原 胃蛋白酶胃蛋白酶nPepsin begins digestion of proteinsnClots milk 合牛奶牛凝结成块合牛奶牛凝结成块Regions of true stomach真胃的区域真胃的区域qEsophageal region食道食道nNonglandular 无腺体无腺体nArea most prone to ulcers溃疡溃疡qCardiac region喷门喷门nProduces mucus, which protects stomach lining产生黏液
17、保护胃内层产生黏液保护胃内层qFundic region胃底胃底nProduces mucus, enzyme, HClnParietal cells-produce HClnChief cells-produce pepsinogenqPyloric region幽门幽门贲门腺体区域胃底腺体区域憩室外部表面幽门食道腺体区域胃切面边缘憩室外部表面幽门腺体区域Normal Esophogeal Area of Pig Stomach猪胃正常的食道猪胃正常的食道Stomach Ulcer in a Human人的胃溃疡人的胃溃疡StomachnSecretions of true stomach真
18、胃分泌作用真胃分泌作用qRennin (abomasum)凝乳酶凝乳酶nClots milkqMucus黏液黏液nProtects lining of stomach from acid and pepsinRuminant Stomach反刍动物的胃反刍动物的胃网胃瓣胃食道瘤胃皱胃小肠瘤胃皱胃网胃气体液体瓣胃Ruminant StomachnRumen 瘤胃瘤胃DevelopmentqIn newborn ruminants the abomasum is the only fully developed part of the stomach.新生反刍动物皱胃充分发育新生反刍动物皱胃充分发
19、育qThe rumen, reticulum and omasum are present, but they are very small and nonfunction.其它胃小而无功能。其它胃小而无功能。Ruminant StomachqConsumption of forages and concentrates and inoculation with rumen bacteria from other ruminants begins fermentation in rumen which caused the rumen to develop. 粗饲料和精饲料消耗和接种瘤胃细菌开
20、始在瘤胃中粗饲料和精饲料消耗和接种瘤胃细菌开始在瘤胃中发酵，引起瘤胃发育。发酵，引起瘤胃发育。qOn average, it takes about 2 3 months in calves and lambs for the rumen to develop. 犊牛和羔羊大约犊牛和羔羊大约2-3个月瘤胃发育期。个月瘤胃发育期。Relative Size of Stomach Compartments胃分隔相对尺寸胃分隔相对尺寸Cattle牛牛, %Sheep绵羊绵羊, %Rumen瘤胃瘤胃 54 (1) 62 (1)Reticulum网胃网胃 7 (4) 11 (3)Omasum瓣胃瓣胃 2
21、6 (2) 5 (4)Abomasum皱胃皱胃 13 (3) 22 (2)Function and Gross Appearance of Stomach CompartmentsPrimary FunctionDistinctive Internal StructureRumen瘤胃瘤胃Fermentation; absorption of VFA, NH3, waterPapillae; 乳头乳头looks like shag carpet粗毛毯粗毛毯Reticulum网网胃胃Fermentation发酵发酵Honeycomb appearance蜂巢蜂巢Omasum、瓣胃瓣胃Reduce
22、 particle size, absorb H2O“Leaves” or many piles looks like a book on edgeAbomasum皱胃皱胃Functions of “true” stomachNone shiny with mucusPapillae of the RumenReticulum (Honeycomb)网胃Omasum (Butchers Bible)瓣胃Fermentation in Rumen and Reticulum瘤胃和网瘤胃和网胃中发酵胃中发酵nThe rumen contains:q25 50 x 109 bacteria/ml细菌
23、细菌q25 50 x 104 protozoa/ml 原生动物原生动物qYeast and fungi also present but in much lower concentrations酵母和真菌酵母和真菌淀粉颗粒淀粉颗粒细菌细菌原虫原虫细菌细菌Fermentation in Rumen and Reticulum瘤胃和网胃中发酵瘤胃和网胃中发酵nAnaerobic microbial digestion of feedstuffs into volatile fatty acids, methane, carbon dioxide, and heat.饲料厌氧微生物发酵生成挥发性饲料
24、厌氧微生物发酵生成挥发性脂肪酸、甲烷、二氧化碳和热量。脂肪酸、甲烷、二氧化碳和热量。nMicrobes synthesize all amino acids, all B vitamins and vitamin K.微生物合成所有氨基酸和微生物合成所有氨基酸和所有所有B族维生素和维生素族维生素和维生素K。nMost unsaturated fatty acids entering the rumen are saturated by the microbes. 绝大多数不饱和脂肪酸生成饱和。绝大多数不饱和脂肪酸生成饱和。Rumination (Chewing the Cud)反刍反刍qPro
25、cess by which ruminants rechew the coarse fibrous part of the diet.饲粮中粗纤维部分饲粮中粗纤维部分qParts of rumination are:nRegurgitation nRemastication nReensalivation nReswallowingRumination (Chewing the Cud)qRechewing reduces particle size and stimulates saliva flow 反复嚼咀降低颗粒尺寸和刺激唾液流动。反复嚼咀降低颗粒尺寸和刺激唾液流动。qDiets lo
26、w in forage result in reduced rumination which causes reduced saliva flow and less buffer entering the rumen 低粗饲料低粗饲料qRuminants spend 610 hours/day ruminating Bloat膨胀膨胀nAccumulation of fermentation gas in rumen that is not belched. 发酵气体积聚，没有排出去发酵气体积聚，没有排出去 BloatEructationqExpelling of gas produced f
27、rom microbial fermentationqDuring peak fermentation 12-30 liters of gas are produced each hourSmall Intestine小肠小肠nDivided into three segments:qDuodenum十二指肠十二指肠nAttached to true stomach, pancreatic and bile ducts enter near the beginning of the duodenumqJejunum空肠空肠nMiddle segmentqIleum回肠回肠nLast segme
28、nt, ends in ileo-cecal valve which regulated flow of digesta into the large intestineSmall IntestinenPrimary site for digestion of proteins, non-fibrous carbohydrates, and lipids. 蛋白质、非纤维型碳水化合物和脂类。蛋白质、非纤维型碳水化合物和脂类。nThe only site for absorption of amino acids, monosaccharides and long chain fatty aci
29、ds. 吸收氨基酸、单糖和长链脂肪酸的唯一位置。吸收氨基酸、单糖和长链脂肪酸的唯一位置。nAll vitamins and minerals can be absorbed in the small intestine. 所有维生素和矿物质能被吸收到小肠中。所有维生素和矿物质能被吸收到小肠中。Small IntestinenLarge amount of surface area in small intestine is due to folds in the wall, presence of villi, and especially microvilli 绒毛绒毛nThe surfac
30、e of the villi are covered withenterocyte cells which contain microvilli. nAbsorption occurs when compounds pass through the microvilli, enter the enterocyte, and are transferred to either the blood or lymph淋巴淋巴.VilliMicrovilli (Brush border)Pancreas胰腺胰腺nEnzymes and buffer from the pancreas enter in
31、to the small intestine via the pancreatic duct.nCell Types:qAcinar CellsnSecrete enzymesqCentroacinar CellsnSecrete buffer n(bicarbonate)qPancreas secrete 1.5 to 2.0 liters of fluid per day for an average humanPancreasnPancreatic enzymes digest starches, dextrins, fats and protein into monosaccharid
32、es, fatty acids and monoglycerides, and amino acids.PancreasLivernSynthesizes bilenBile stored in gall bladder (except in horses)nBile emulsifies large fat globules into a suspension of very fine dropletsnSphincter of OddiqCloses bile duct preventing bile secretion into the duodenumNormal Human Live
33、rCirrhosis of the liverLarge IntestinenMain parts:qCecum (blind pouch)qColonqRectumnActive site of fermentation in all farm animalsLarge IntestinenElectrolytes, water, and VFA are absorbed from the large intestine.nAmino acids, monosaccharides, and long chain fatty acids are not absorbed from the large intestine.End
