Fish Hatchery Management - fisheries & aquaculture

N UTRITION. AN D }.EEDING 227The available calories in catfish feeds and estimated feed conversions canbe calculated by the same procedures as for salmonid feeds, with appropriatevalues for catfish beins substituted.Vitamin RequirementsVitamins are not nutrients, but are dietary essentials required in smallquantities by all forms of plant and animal life. They are catalytic tn natureand function as part of an enzyme system.For convenience, vitamins are broadly classified as fat-soluble vitaminsor water-soluble vitamins. The fat-soluble vitamins usually are found associatedwith the lipids of natural foods and include vitamins A, D, E, andK. The water soluble vitamins include vitamin C and those of the B complex:thiami"e (Br), riboflavin (Br), biotitr, folic acid, cyanocobalamin (Brz)and inositol.Vitamins are distributed widely in ingredients used in fish feeds. Some,such as yeast, contain high levels of several vitamins. The level of vitaminssupplied by the ingredients in the feed usually is not adequate to meet thefishes' requirements. These requirements are presented in Table 24. MostTABLL 24. vt'fAMrnw REqutRF]ML,N rs ExPRESSED AS MILLIGRAMS oR lN l lil{NA-I'ION*AL UNI'IS (IU) PER POUND OF DRY IEI,D FOR SAI,MONIDS AND WARMWA'f!]RFISHI'S. {SCIURCI. NA'I'IONAI, RF]SL,ARCTI COUNCIL I973, I1)77,)WARMWAl !,R I'ISHI]SSUPPI,I,]NII.]N'TALcoNIl'l-lll'lVII AMINSAI,MONII)Sl'EEl)F EEI)A (IU)Dr(ru)E (IU]K'I'hiamincRiboflavinPyridoxinePantothenic acidBiotinCholineVitamin Bt2N iacinAscorbic acidFolic acidI nositol90tJla\I ll. (t3(i.39.1,1.5I u.20..15 "I 3(t20.001){;tt+5.,42.3IU2IX)IJ1005'2.:l0.1) li.2ll3.2 52000.0009-0.0017.7 t2.70-.15.,1U0'2,497.15-1.'2',2.7,t.ll1).19.19.1'22.70.0,t2ir00.00915.,113.(t-,1.5..12.:l,15..1dRequired lcvel is not cstablished."Brown trout require ts'ice the level presented