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DigestiveSystems消化系统1DigestiveSystems消化系统2四、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？DigestiveSystems消化系统3四、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
2、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？设为设为x x，则则x90%=5%25%x90%=5%25%x=x=（5%5%90%90%）25%=18%25%=18%DigestiveSystems消化系统4DIGESTION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DigestiveSystems消化系统5Key concepts about the digestive system and digesti
3、onLarge complex molecules,like proteins,polysaccharides,and triglycerides must be broken down into their 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 specif
4、ic types of chemical bonds.If an enzyme is not present,digestion of that molecule does not occur 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 fi
5、ber).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）DigestiveSystems消化系统6Key concepts about 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
6、 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 improves 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 d
7、ictate 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！DigestiveSystems消化系统7Gastrointestinal TractnComplex physiologically and anatomicallynExtends from mouth to anusnFunction
8、sqDigestionqAbsorptionqProtect body from:qRemove undigested material and wastesqImmunological functionqMetabolismqEndocrine functions(Hormones)nSite of fermentation(symbiosis)DigestiveSystems消化系统8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DigestiveSystems消化系统9RuminantCattle,Sheep,Goats反刍动物反刍动物-牛，绵羊，山
9、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DigestiveSystems消化系统10Simplified Digestive SystemsDigestiveSystems消化系统11DigestiveSystems消化系统12Mouth and Saliva嘴和唾液嘴和唾液nFunction of the mouth 嘴的功能嘴的功能qTake in food 采食采食nPrehensile structureqHorses-lips 马马-唇唇qCattle-tongue 牛牛-牙齿牙
10、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DigestiveSystems消化系统13Pig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DigestiveSystems消化系统14DigestiveSystems消化系统15Grin
11、ding 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 DigestiveSystems消化系统16Mouth 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
12、粉酶）开始淀粉酶解（淀粉酶）qProduce buffer to counteract acid in stomach产生缓冲液中和胃酸产生缓冲液中和胃酸DigestiveSystems消化系统17Mouth 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 function
13、sqUreaqEnzymesqMucoproteins黏蛋白黏蛋白DigestiveSystems消化系统18Esophagus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 throughoutDigestiveSystems消化系统19EsophagusnExtended
14、 by reticular groove(esophageal groove)in young ruminantsqAllows passage of milk 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DigestiveSystems消化系统20Stomach胃胃n(Glandular
15、 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 gradual 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、挥发性吸收
16、乙醇、阿司匹林、挥发性脂肪酸和其它不同化合物。脂肪酸和其它不同化合物。qThere is no absorption of monosaccharides,amino acids,or long 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。DigestiveSystems消化系统21StomachnSecretions of true stomach真胃分泌作用真胃分泌作用qHClnDenatures protein-breaks intermolecular bondsnKills most bac
17、teria 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 converts 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DigestiveSystems消化系统22Regions of true stomach真胃的区域真胃的区域qEso
18、phageal 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
19、边缘憩室外部表面幽门腺体区域DigestiveSystems消化系统23Normal 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DigestiveSystems消化系统24StomachnSecretions of true stomach真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 pepsinDigestiveSystems消化系
20、统25Ruminant 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DigestiveSystems消化系统26DigestiveSystems消化系统27Ruminant 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育qThe rumen,reticulum and omasum are present,but they are
21、 very small and nonfunction.其它胃小而无功能。其它胃小而无功能。DigestiveSystems消化系统28Ruminant 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
22、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。DigestiveSystems消化系统29Relative 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26(2)5(4)Abomasum皱胃皱胃13(3)22(2
23、)DigestiveSystems消化系统30Function 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 particle size,abs
24、orb H2O“Leaves”or many piles looks like a book on edgeAbomasum皱胃皱胃Functions of“true”stomachNone shiny with mucusDigestiveSystems消化系统31Papillae of the RumenDigestiveSystems消化系统32Reticulum(Honeycomb)网胃DigestiveSystems消化系统33Omasum(Butchers Bible)瓣胃DigestiveSystems消化系统34DigestiveSystems消化系统35Fermentatio
25、n 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DigestiveSystems消化系统36Fermentation in Rumen and Reticulum瘤胃和网胃中发酵瘤胃和网胃中发酵nAnaerobic mic
26、robial 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
27、 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。DigestiveSystems消化系统37Rumination(Chewing the Cud)反刍反刍qProcess 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 nReswallowingDigestive
28、Systems消化系统38Rumination(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 low 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 ruminat
29、ing DigestiveSystems消化系统39Bloat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DigestiveSystems消化系统40BloatDigestiveSystems消化系统41EructationqExpelling of gas produced from microbial fermentationqDuring peak fermentation 12-30 liters of gas are produced each h
30、ourDigestiveSystems消化系统42Small 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 segment,ends in ileo-cecal valve which regulated flow of digesta into the l
31、arge intestineDigestiveSystems消化系统43Small 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 acids.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 vitam
32、ins 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。DigestiveSystems消化系统44Small 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 surface of the villi are covered withente
33、rocyte 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.DigestiveSystems消化系统45DigestiveSystems消化系统46VilliMicrovilli(Brush border)DigestiveSystems消化系统47Pancreas胰腺胰腺nEnzymes and buffer
34、 from the pancreas enter into 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 humanDigestiveSystems消化系统48PancreasnPancreatic enzymes digest starch
35、es,dextrins,fats and protein into monosaccharides,fatty acids and monoglycerides,and amino acids.PancreasDigestiveSystems消化系统49LivernSynthesizes bilenBile stored in gall bladder(except in horses)nBile emulsifies large fat globules into a suspension of very fine dropletsnSphincter of OddiqCloses bile
36、 duct preventing bile secretion into the duodenumDigestiveSystems消化系统50Normal Human LiverCirrhosis of the liverDigestiveSystems消化系统51Large IntestinenMain parts:qCecum(blind pouch)qColonqRectumnActive site of fermentation in all farm animalsDigestiveSystems消化系统52Large 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.DigestiveSystems消化系统53EndDigestiveSystems消化系统54
