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

1、Chapter 1-5Vitamins,1.General2.Fat-soluble vitamin3.Water-soluble vitamin,Generalorganic compoundsrequired in trace amounts from an exogenous source(usually the diet)Function independent of enzymes,or in some cases such as vitamin K,may have coenzyme roles（辅酶的作用）normal growth reproduction health Vit

2、amins are classified as fat soluble and water soluble.,Fat Soluble VitaminsVitamin AVitamin DVitamin EVitamin K,Water soluble vitamins primarily coenzyme functionsvitamin B complex VB1(thiamin-HCl,硫胺素)VB2(riboflavin,核黄素)VB3(calcium pantathenate，泛酸)VB5(nicotinic acid，烟酸)VB6(pyridoxine，吡哆素)VB7,Folic a

3、cid(retinal)VB12(cyanocobalamin，氰钴素)choline（胆碱）inositol（肌醇）required in larger quantities and have vitamin C functions other than coenzymes(不作辅酶）(ascorbic acid),biotransformationCholine channel catfishmethyl donors(methionine)choline￥38.5-39.0/kg￥5.0/kg（50%）,Factors affecting the vitamin requirements

4、(1)Size(2)Age(3)growth rates(4)various environmental factors(5)nutrient interrelationships（相互关系）,fairly wide ranges in requirement values for growth in the same species(see Table 1-15)EX.Vitamin E requirement in rainbow troutRequirement Response Criteria25IU/kg WG,absence of deficiency signs(ADS,未出现

5、缺乏症）30IU/kg WG,ADS50IU/kg ascorbic acid stimulated lipid peroxidation(AASLP,维C 刺激下的脂肪过氧化）100IU/kg maximum liver storage（MLS，肝脏最大积累量）,In addition,the requirement values determined by maximum liver storage or based on certain enzyme data(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),are often much higher than the req

6、uirement values based on weight gain and absence of deficiency signs(经常大大高于根据增重率和缺乏症而测定的数据);,A summary of vitamin deficiency signs in Appendix Table A-3,2.Fat-Soluble VitaminsAbsorption and storagealong with dietary fatsconditions favorable for fat absorption also enhance the absorption of fat-solub

7、le vitaminsstored by animals if dietary intake exceeds metabolic needsproduce a toxic condition(hypervitaminosis,维生素过剩症)It is unlikely to occur under practical conditions.,the nutritional history of experimental fish prior to their use in requirement studies becomes criticalThe time required to depl

8、ete fish of their stored fat-soluble vitamins is highly variable（鱼用于消耗体内储存的脂溶性维生素时间差异很大）.Difference in vitamin intake prior to an experimentmay be responsible for some of the conflicting findings on the induction and severity of deficiency signs（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）,2.1 Vitamin Arequired in

9、 vertebrates forregeneration（再生）of the light-sensitive compound rhodopsin（视紫红质）in the retina（视网膜）of the eye.proper growth,reproduction,resistance to infection（抗感染）,and the maintenance of differentiated epithelia and mucus secretions（上皮分化及粘液分泌）,Vitamin A in three forms(1)as an alcohol(retinol)(视黄醇)(2

10、)an aldehyde(retinal)(视黄醛),(3)and an acid(retinoic acid)(视黄酸)In freshwater fish the reversible reactions of oxidation and reductionretinol 3-dehydroretinol(视黄醇3-脱氢视黄醇)retinol retinal(视黄醇视黄醛）3-dehydroretinol 3-dehydroretinal(3-脱氢视黄醇3-脱氢视黄醛),Tilapia retinol 3-dehydroretinolChannel catfish-carotene(胡萝卜

11、素)vitamin A1 and A2 in 1:1 ratioonly if the dietary concentration exceeded 2,000 IU/kgCold-water fish-carotene as a vitamin A precursor（利用胡萝卜素为维生素A前体）.,Tilapia-carotene and canthaxanthin（角黄素）biotransformed vitamin A1 in liverdihydroxyearotenoids（二羟胡萝卜素）astaxanthin（虾青素）zeaxanthin（玉米黄素）,tunaxanthin（胡萝

12、卜二醇）bioconverted vitamin A2In mammalsCarotenoids have been found to fulfill functions independent of vitamin A（具有多种与维生素A无关的生物功能）.,Vitamin A deficiency Rainbow troutanemia（贫血）,twisted gill opercula（鳃盖扭曲）,an hemorrhagic in the eyes and base of fins（眼和鳍基出血）Brook trout poor growth,high mortality,eye les

13、ions（损伤）edematouseyes（水肿）displaced lens（晶状体移位）and degeneration of the retina（视网膜退化）,in channel catfish fed 0.4 mg of-carotenen/kg of diet for 3 years developed exophthalmia（突眼症）,edema(水肿),and hemorrhagic kidney（肾出血）.in common carpfed a vitaminA-dificient diet after 8 to 11 weeks,anorexia（厌食）,pale bo

14、dy color（体色发白）,hemorrhagic skin and fins（皮肤和鳍出血）,exophthalmia（突眼）,and twisted gill opercula（鳃盖扭曲）occurred.,Rapidly growing yellowtail fingerlings（幼鱼）fed a vitamin A-deficient diet developed deficiency signs in 20 days including arrested growth of gill opercula（鳃盖生长抑制）,dark pigmentation（黑色素沉着）,anemia

15、（贫血）,and hemorrhage（出血）in the eyes and liver,accompanied by high mortality（伴随高的死亡率）.Vitamin A adding forms in fish feeds the acetate（乙酸酯）,palmitate（棕榈酸酯）,or propionate ester（丙酸酯）in the form of free-flowing beadlets(自由流动的微粒)in a multivitamin premix(多维预混料).,1.2 Vitamin DSources of vitamon D(1)ergocalc

16、iferol(麦角钙化醇)(D2,which occurs predominantly in plants主要存在于植物)(2)cholecalciferol（胆钙化醇）(D3,which occur in animals).Both forms of D are hydroxylated（羟基化）in the liver to the 25-hydroxy（羟基）forms.The 25-hydroxy-D3（25-羟基-D3）is further hydroxylated in the kidney to 1,25-dihydroxy vitamin D3（1，25-二羟基-D3）,1，25-dihydroxy-D3 is the biologically active form of vitamin D responsible for facilitating mobilization（动员）,transport（转运）,absorption（吸收）,and use of calcium and phosphorus（钙磷）in concert with（协同作用）the act