216 FISH HATCHERY MANAGEMENT 



feed that contains at least 50''] protein; at 6—8 weeks the requirement de- 

 creases to 40*: of the feed and to about 35% of the feed for yearling sal- 

 mo nids. 



Recor :ein levek in trout feeds as percent of the diet are: 



Starter feed fi:y 45—55% 



Grower feed fingerlings 35-5% 



Production feed (older fish 30-40% 



The level of protein required in feed varies with the quality- and propor- 

 tions :: -^ -:i. r:::e:rLi ihat make up the feed. Between 0.5 and 0.7 pound 

 ;tary- protein is re: _ ri :o produce a pound of trout fed a balanced 

 jjatcherv rf £ The requireiiient for protein is also temperature- dependent. 

 The opcLn^ prote:- 'rr'. :- :'-e fe^d for chinook salmon is 4-0 ai 47"F 



?? : rzrv rv catts:-: 7zzds 



T-r 7^\^:^ :::i5 ;: ri::-;- ire rich •'- T-r-ein. Catfish may mecaboiize 

 5-:me i r.^r i:::f - :;: r'rrr- Prcte.r .. .:zarion is affected by the pro- 

 -r - ;:_.-:f i.-i ■• i:f: :-rmrer3.r.:rr. L'-'-t :-:::5h convert the best animal 

 z:.- 7 ::_::t ::;- —.-.- : : :. — r; z-..-: :-iz :hey do the best plant 

 --rzr. soyiea.- mei.. I: li - r ::hy thai a combination of protein 

 ii-rirs T I: iT-r: wrs- "zziwz. Tites :L=.- a.- • wz.z-- source. In catfish 

 :eeas. a: --'. ' :: .-r iir.ir. i- "r - tt:. :t — t-: should be animal 



reins w-e- :-r;. ire red a: cem.- 



'"'F cr ce.i'A. Hc-rt'e% er. a mix- 



. _-.^v at both extremies. The pax- 



- "r pr::rm z-z . Z'—.rri ::: :i:::3- i:^ i : size-rr.i:^ 



Frv :: : 'irz - z\ \'-^'i 



1 



Fi-r : - .:- :s 25-^5^ 



\^rT- :i -r t1 ii mu:- 2^ me- «;!. ea.i. izi -t reed is bala.i:- 



