饲料添加剂第二章营养性添加剂氨基酸.pptx

饲料添加剂第二章营养性添加剂氨基酸Additivesthatinfluencefeedqualityincludepelletbinders,preservatives(suchasantimicrobialcompoundsandantioxidants),andfeedingstimulants.Suchadditivesarecommonlyincludedincommercialformulationstoachieveandmaintainoptimalphysicalandchemicalcharacteristics.Otheradditivesthatmaydirectlyaffectfishperformanceorproductqualityincludeacidifierschemotherapeutants,pigments,exogenous,immunostimulants,probioticandprebiotics.Mostoftheseadditivesaresupplementedtodietformulationstoachievespecificpurpose.Lysineisabundantinbodyproteinoffishandotheranimals.Lysineisfoundinhighconcentrationiningredientssuchasfishmealandbloodmealandinlowconcentrationsinsomeplantproteiningredients,notablycerealgrainbyproducts,suchascornglutenmealandwheatgluten.Duetothereactivenatureofitsε-aminogroup,lysineissensitivetoheatdamageandtononenzymaticglycolyzationreactionsresultinginproductionofMaillardreactionproducts.Theseresultinirreversiblechemicaldamagetolysineandreducetheamountofavailablelysineinfeedstuffsandfeeds.Consequently,lysineiscommonlythefirstlimitingaminoacidinplantproteininfeeds,particularlythoseformulatedwithhighlevelsofplantproteiningredientsorwithproteiningredientsprocessedunderharshconditions.第二章营养性添加剂营养性添加剂第一节氨基酸一、氨基酸L型－能够被动物吸收利用D型－大多数（Met除外）不能被动物吸收利用或利用率较低。天然饲料中的氨基酸绝大部分是以L型异构体存在。自然界中的微生物既能合成L型也能合成D型氨基酸。化学合成的氨基酸多为L、D型混合物。氨基酸构型必须氨基酸(EAA):在动物体内不能合成，或合成速度不能满足机体需要，必须由外源供给一定数量，否则就不能满足动物机体的正常需要。非必需氨基酸(NEAA):在动物体内合成比较多，或动物对其需要较少，或可由其他种类氨基酸转变而成，即使无外源供给也能保证动物正常生长发育的需要。必须氨基酸(EAA):氨基酸平衡理论必需氨基酸缺乏二、饲料用氨基酸添加剂1）赖氨酸（Lysine）（1）L-赖氨酸（2）L-赖氨酸盐酸盐（2）L-赖氨酸盐酸盐2）蛋氨酸（Methionine）2）蛋氨酸（1）DL-蛋氨酸（DL-methionine）（2）DL-蛋氨酸羟基类似物（DL-methioninehydroxyanalogue,MHA）（3）DL-羟基蛋氨酸类似物钙盐（DL-methioninehydroxyanaloguecalcium）3）色氨酸（Tryptophan）4）苏氨酸（L-threonine）5）甘氨酸（Glycine）6）精氨酸（Arginine）7）谷氨酸（Glutaminidacid或Glutamicacid）三、游离态氨基酸和包膜氨基酸三、游离态氨基酸和包膜氨基酸选用限制性氨基酸的注意事项