水产动物营养与饲料学－双语教学课件chapter1-5-Vitamins.ppt

水产动物营养与饲料学－双语教学课件chapter1-5-Vitamins.ppt

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Chapter1-5Vitamins,1.General2.Fat-solublevitamin3.Water-solublevitamin,Generalorganiccompoundsrequiredintraceamountsfromanexogenoussource（usuallythediet）Functionindependentofenzymes,orinsomecasessuchasvitaminK,mayhavecoenzymeroles（辅酶的作用）normalgrowthreproductionhealthVitaminsareclassifiedasfatsolubleandwatersoluble.,FatSolubleVitaminsVitaminAVitaminDVitaminEVitaminK,WatersolublevitaminsprimarilycoenzymefunctionsvitaminBcomplexVB1（thiamin-HCl,硫胺素）VB2（riboflavin,核黄素）VB3（calciumpantathenate，泛酸）VB5（nicotinicacid，烟酸）VB6（pyridoxine，吡哆素）VB7,Folicacid（retinal）VB12（cyanocobalamin，氰钴素）choline（胆碱）inositol（肌醇）requiredinlargerquantitiesandhavevitaminCfunctionsotherthancoenzymes（不作辅酶）（ascorbicacid）,biotransformationCholinechannelcatfishmethyldonors（methionine）choline￥38.5-39.0/kg￥5.0/kg（50%）,Factorsaffectingthevitaminrequirements

（1）Size

（2）Age（3）growthrates（4）variousenvironmentalfactors（5）nutrientinterrelationships（相互关系）,fairlywiderangesinrequirementvaluesforgrowthinthesamespecies（seeTable1-15）EX.VitaminErequirementinrainbowtroutRequirementResponseCriteria25IU/kgWG,absenceofdeficiencysigns（ADS,未出现缺乏症）30IU/kgWG,ADS50IU/kgascorbicacidstimulatedlipidperoxidation（AASLP,维C刺激下的脂肪过氧化）100IU/kgmaximumliverstorage（MLS，肝脏最大积累量）,Inaddition,therequirementvaluesdeterminedbymaximumliverstorageorbasedoncertainenzymedata（表1-15中根据肝脏最大储存量或些酶的数据而测定的需求值）,areoftenmuchhigherthantherequirementvaluesbasedonweightgainandabsenceofdeficiencysigns（经常大大高于根据增重率和缺乏症而测定的数据）;,AsummaryofvitamindeficiencysignsinAppendixTableA-3,2.Fat-SolubleVitaminsAbsorptionandstoragealongwithdietaryfatsconditionsfavorableforfatabsorptionalsoenhancetheabsorptionoffat-solublevitaminsstoredbyanimalsifdietaryintakeexceedsmetabolicneedsproduceatoxiccondition（hypervitaminosis,维生素过剩症）Itisunlikelytooccurunderpracticalconditions.,thenutritionalhistoryofexperimentalfishpriortotheiruseinrequirementstudiesbecomescriticalThetimerequiredtodepletefishoftheirstoredfat-solublevitaminsishighlyvariable（鱼用于消耗体内储存的脂溶性维生素时间差异很大）.Differenceinvitaminintakepriortoanexperimentmayberesponsibleforsomeoftheconflictingfindingsontheinductionandseverityofdeficiencysigns（可能是导致维生素缺乏症现象和严重性方面存在争论的部分原因）,2.1VitaminArequiredinvertebratesforregeneration（再生）ofthelight-sensitivecompoundrhodopsin（视紫红质）intheretina（视网膜）oftheeye.propergrowth,reproduction,resistancetoinfection（抗感染）,andthemaintenanceofdifferentiatedepitheliaandmucussecretions（上皮分化及粘液分泌）,VitaminAinthreeforms

（1）asanalcohol（retinol）（视黄醇）

（2）analdehyde（retinal）（视黄醛）,（3）andanacid（retinoicacid）（视黄酸）Infreshwaterfishthereversiblereactionsofoxidationandreductionretinol3-dehydroretinol（视黄醇3-脱氢视黄醇）retinolretinal（视黄醇视黄醛）3-dehydroretinol3-dehydroretinal（3-脱氢视黄醇3-脱氢视黄醛）,Tilapiaretinol3-dehydroretinolChannelcatfish-carotene（胡萝卜素）vitaminA1andA2in1:

1ratioonlyifthedietaryconcentrationexceeded2,000IU/kgCold-waterfish-caroteneasavitaminAprecursor（利用胡萝卜素为维生素A前体）.,Tilapia-caroteneandcanthaxanthin（角黄素）biotransformedvitaminA1inliverdihydroxyearotenoids（二羟胡萝卜素）astaxanthin（虾青素）zeaxanthin（玉米黄素）,tunaxanthin（胡萝卜二醇）bioconvertedvitaminA2InmammalsCarotenoidshavebeenfoundtofulfillfunctionsindependentofvitaminA（具有多种与维生素A无关的生物功能）.,VitaminAdeficiencyRainbowtroutanemia（贫血）,twistedgillopercula（鳃盖扭曲）,anhemorrhagicintheeyesandbaseoffins（眼和鳍基出血）Brooktroutpoorgrowth,highmortality,eyelesions（损伤）edematouseyes（水肿）displacedlens（晶状体移位）anddegenerationoftheretina（视网膜退化）,inchannelcatfishfed0.4mgof-carotenen/kgofdietfor3yearsdevelopedexophthalmia（突眼症）,edema（水肿）,andhemorrhagickidney（肾出血）.incommoncarpfedavitaminA-dificientdietafter8to11weeks,anorexia（厌食）,palebodycolor（体色发白）,hemorrhagicskinandfins（皮肤和鳍出血）,exophthalmia（突眼）,andtwistedgillopercula（鳃盖扭曲）occurred.,Rapidlygrowingyellowtailfingerlings（幼鱼）fedavitaminA-deficientdietdevelopeddeficiencysignsin20daysincludingarrestedgrowthofgillopercula（鳃盖生长抑制）,darkpigmentation（黑色素沉着）,anemia（贫血）,andhemorrhage（出血）intheeyesandliver,accompaniedbyhighmortality（伴随高的死亡率）.VitaminAaddingformsinfishfeedstheacetate（乙酸酯）,palmitate（棕榈酸酯）,orpropionateester（丙酸酯）intheformoffree-flowingbeadlets（自由流动的微粒）inamultivitaminpremix（多维预混料）.,1.2VitaminDSourcesofvitamonD

（1）ergocalciferol（麦角钙化醇）（D2,whichoccurspredominantlyinplants主要存在于植物）

（2）cholecalciferol（胆钙化醇）（D3,whichoccurinanimals）.BothformsofDarehydroxylated（羟基化）inthelivertothe25-hydroxy（羟基）forms.The25-hydroxy-D3（25-羟基-D3）isfurtherhydroxylatedinthekidneyto1,25-dihydroxyvitaminD3（1，25-二羟基-D3）,1，25-dihydroxy-D3isthebiologicallyactiveformofvitaminDresponsibleforfacilitatingmobilization（动员）,transport（转运）,absorption（吸收）,anduseofcalciumandphosphorus（钙磷）inconcertwith（协同作用）theact