INTRODUCTION 



This paper is a report of the 19h9 salmon feeding trials at the 

 Leavenworth Laboratory of the Fish and Wildlife Service. The piirpose 

 of these trials was to develop improved diets for fingerling blueback 

 salmon ( Oncorh^Tichus nerka ) by feeding these fish various foods under 

 actual hatchery conditions. 



The 19h9 studies were a continuation of previous feeding trials con= 

 ducted with fingerling blueback salmon at this laboratory. In these 

 feeding trials, the single component studies included tuna liver and 

 the four major segments of salmon viscera. The remainder of the diets, 

 with the exception of the beef liver control, were of the composite type. 

 The first group of this latter type i-ras designed to test the effect of 

 salmon waste meals at different water temperatures. The second ^J-'oup 

 evaluated the effect of various drying processes on the utilisation of 

 salmon waste meals. The third was a test of hake ( Merluccius prod uctus) 

 as a substitute for hog spleen or hog liver. The fourth was an eva]-° 

 uation of various anti-anemic supplements such as crab meal, beef liver, 

 and herring stickwater in a diet that previously had produced anemia. 

 The fifth and last group was a comparison of crab meal and two salmon 

 waste meals. 



The presentation of this investigation is divided into three main 

 parts. The first part explains the conditions of experiment and in- 

 cludes a short account of the water temperatures prevailing during the 

 experimental period as well as a description of the experimental tech- 

 niques. The second part gives a detailed account of the experimental 

 results. The last part, which is based on the experimental results, 

 gives two recommended diets and substitutions or supplements that may 

 be used in these diets. 



