DigestiveSystems消化系统优秀公开课

无氮浸出物图概略养分与饲料组成之间的关系

饲料

无机物（粗灰分或矿物质）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某饲料新鲜基础含CP5%，水分75%，求饲料风干基础（含水10%）下含蛋白质多少？DIGESTION消化AnatomyandFunctionoftheGastrointestinalTract胃肠道解剖和功能KeyconceptsaboutthedigestivesystemanddigestionLargecomplexmolecules,likeproteins,polysaccharides,andtriglyceridesmustbebrokendownintotheirsimplestpartbeforetheyareabsorbedintothebloodorlymph.Thisisthejobofthedigestivesystem

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。Digestionrequiresenzymesthatbreakspecifictypesofchemicalbonds.Ifanenzymeisnotpresent,digestionofthatmoleculedoesnotoccur

消化需要酶。Therearetwosourcesofdigestiveenzymes:thosemadebytheanimal(digestsolubleCHO,proteinandlipids)andthosemadebymicrobesduringfermentation(digestsolubleCHO,proteinandlipidsandfiber).

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）KeyconceptsaboutthedigestivesystemanddigestionForoptimumutilization,digestionorfermentationneedstooccureitherinfrontof,orinsidethepartofdigestivesystemthatabsorbsthefinalproductsproducedbydigestion

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。Fermentationimprovesoverallutilizationoffeedsforallanimals发酵改善所有动物饲料充分利用。Differencesinsizeofsomepartsofthedigestivesystemandlocationoffermentationwithinthedigestivesystemdictatethetypesoffeedsanimalscanutilizeandthepropermeansoffeeding.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。为什么胃没有被消化了！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Ruminant—Cattle,Sheep,Goats反刍动物----牛，绵羊，山羊Nonruminants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SimplifiedDigestiveSystemsMouthandSaliva嘴和唾液Functionofthemouth嘴的功能Takeinfood采食PrehensilestructureHorses-lips马-唇Cattle-tongue牛-牙齿Pigs-lips猪-唇Sheep-lips绵羊-唇Taste–acceptorrejectfood品尝Chewing嚼ReducesparticlesizewhichimprovesdigestibilityStimulatessalivaflowMixdigestawithsaliva混合Pig猪Horse马Sheep绵羊Cattle牛臼齿切割和犬齿牙床MouthandSalivaFunctionofsaliva唾液的功能Lubricatefoodtoallowswallowingandmixingoffoodinstomachofnonruminants润滑食物便于吞咽和食物在反刍动物胃里混合Initiateenzymaticdigestion(amylase)ofstarch开始淀粉酶解（淀粉酶）Producebuffertocounteractacidinstomach产生缓冲液中和胃酸MouthandSalivaCompositionofsaliva唾液成分Water水Inorganiccomponents无机成分UsedtosupplymineralstodigestaandbufferstoregulatepHOrganiccomponents有机成分NeededfordigestivefunctionsUreaEnzymesMucoproteins黏蛋白Esophagus食道Musculartube肌管Extendsfrompharynxtocardiaofstomach咽至贲门Striatedmuscle纹状肌whichchangestosmoothmuscle平滑肌EsophagusofdogsandruminantshavestriatedmusclethroughoutStomach胃(GlandularorTrue)Stomach腺胃或真胃Functionsoftruestomach真胃的功能Mixingoffood混合Holdfoodforgradualreleaseintosmallintestine食物进入小肠ProductionofHClandpepsinogen盐酸和胃蛋白酶原Absorptionofalcohol,aspirin,volatilefattyacids(ruminants),andvariousothercompounds.吸收乙醇、阿司匹林、挥发性脂肪酸和其它不同化合物。Thereisnoabsorptionofmonosaccharides,aminoacids,orlongchainfattyacidsinthestomach.

胃不吸收单糖、氨基酸或者长脂肪酸链。StomachSecretionsoftruestomach真胃分泌作用HClDenaturesprotein-breaksintermolecularbondsKillsmostbacteriapresentinfoodstuffsActivatespepsinogenRupturesstarchgranules破裂淀粉颗粒Pepsinogen胃蛋白酶原HClconvertspepsinogentopepsintheactiveenzyme胃蛋白酶原胃蛋白酶PepsinbeginsdigestionofproteinsClotsmilk合牛奶牛凝结成块

Regionsoftruestomach真胃的区域Esophagealregion食道Nonglandular无腺体Areamostpronetoulcers溃疡Cardiacregion喷门Producesmucus,whichprotectsstomachlining产生黏液保护胃内层Fundicregion胃底Producesmucus,enzyme,HClParietalcells-produceHClChiefcells-producepepsinogenPyloricregion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StomachSecretionsoftruestomach真胃分泌作用Rennin

(abomasum)凝乳酶ClotsmilkMucus黏液ProtectsliningofstomachfromacidandpepsinRuminantStomach

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RuminantStomachConsumptionofforagesandconcentratesandinoculationwithrumenbacteriafromotherruminantsbeginsfermentationinrumenwhichcausedtherumentodevelop.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。Onaverage,ittakesabout2–3monthsincalvesandlambsfortherumentodevelop.

犊牛和羔羊大约2-3个月瘤胃发育期。RelativeSizeof

StomachCompartments胃分隔相对尺寸Cattle牛,%Sheep绵羊,%Rumen瘤胃

54(1)

62(1)Reticulum网胃

7(4)

11(3)Omasum瓣胃

26(2)

5(4)Abomasum皱胃

13(3)

22(2)FunctionandGrossAppearance

ofStomachCompartmentsPrimaryFunctionDistinctiveInternalStructureRumen瘤胃Fermentation;absorptionofVFA,NH3,waterPapillae;乳头lookslikeshagcarpet粗毛毯Reticulum网胃Fermentation发酵Honeycombappearance蜂巢Omasum、瓣胃Reduceparticlesize,absorbH2O“Leaves”ormanypiles–lookslikeabookonedgeAbomasum皱胃Functionsof“true”stomachNone–shinywithmucusPapillaeoftheRumenReticulum(Honeycomb)网胃Omasum(ButchersBible)瓣胃Fermentationin

RumenandReticulum瘤胃和网胃中发酵Therumencontains:25–50x109bacteria/ml细菌25–50x104protozoa/ml原生动物Yeastandfungialsopresentbutinmuchlowerconcentrations酵母和真菌淀粉颗粒细菌原虫细菌FermentationinRumenandReticulum瘤胃和网胃中发酵Anaerobicmicrobialdigestionoffeedstuffsintovolatilefattyacids,methane,carbondioxide,andheat.饲料厌氧微生物发酵生成挥发性脂肪酸、甲烷、二氧化碳和热量。Microbessynthesizeallaminoacids,allBvitaminsandvitaminK.微生物合成所有氨基酸和所有B族维生素和维生素K。Mostunsaturatedfattyacidsenteringtherumenaresaturatedbythemicrobes.

绝大多数不饱和脂肪酸生成饱和。Rumination

(ChewingtheCud)

反刍Processbywhichruminantsrechewthecoarsefibrouspartofthediet.饲粮中粗纤维部分Partsofruminationare:RegurgitationRemasticationReensalivationReswallowingRumination

(ChewingtheCud)

Rechewingreducesparticlesizeandstimulatessalivaflow

反复嚼咀降低颗粒尺寸和刺激唾液流动。Dietslowinforageresultinreducedruminationwhichcausesreducedsalivaflowandlessbufferenteringtherumen低粗饲料Ruminantsspend6–10hours/day

ruminating

Bloat膨胀Accumulationoffermentationgasinrumenthatisnotbelched.发酵气体积聚，没有排出去

BloatEructationExpellingofgasproducedfrommicrobialfermentationDuringpeakfermentation12-30litersofgasareproducedeachhourSmallIntestine小肠Dividedintothreesegments:Duodenum十二指肠Attachedtotruestomach,pancreaticandbileductsenternearthebeginningoftheduodenumJejunum空肠MiddlesegmentIleum回肠Lastsegment,endsinileo-cecalvalvewhichregulatedflowofdigestaintothelargeintestineSmallIntestinePrimarysitefordigestionofproteins,non-fibrouscarbohydrates,andlipids.蛋白质、非纤维型碳水化合物和脂类。Theonlysiteforabsorptionofaminoacids,monosaccharidesandlongchainfattyacids.

吸收氨基酸、单糖和长链脂肪酸的唯一位置。Allvitaminsandmineralscanbeabsorbedinthesmallintestine.所有维生素和矿物质能被吸收到小肠中。SmallIntestineLargeamountofsurfaceareainsmallintestineisduetofoldsinthewall,presenceofvilli,andespeciallymicrovilli绒毛Thesurfaceofthevilliarecoveredwith enterocytecellswhichcontainmicrovilli.Absorptionoccurswhencompoundspassthroughthemicrovilli,entertheenterocyte,andaretransferredtoeitherthebloodorlymph淋巴.VilliMicrovilli(Brushborder)Pancreas胰腺Enzymesandbufferfromthepancreasenterintothesmallintestineviathepancreaticduct.CellTypes:AcinarCellsSecreteenzymesCent