deficiency. In the combination diet this deficiency appeared to be 

 adequately covered. Because of the excellent growth potential of herring, 

 further experimentation might determine proper combinations which would 

 improve the feeding consistency yet retain the grovrth advantage. 



5. A hog liver plus salmon viscera and a hog liver and salmon 

 viscera meal combination were adquate substitutes for the meat-viscera 

 and meat-viscera-meal control diets. These diets produced growth rates 

 as good or better than their comparable controls. They have excellent 

 possibilities as production diets. 



6. Tuna liver substituted for beef liver in the meat-viscera con- 

 trol diet produced comparable gains during the cold water period but 

 resulted in a significantly lower growth rate during the warm water 

 period when 10 percent meal was added to both diets. No anemia developed 

 during the 2l4.-week feeding period. A tuna liver and salmon viscera meal 

 combination resulted in an acute hypervitaminosis A after 8 weeks of 

 feeding. Tuna liver because of its low growth potential and high vitamin 

 A content is not recommended for inclusion in production diets. 



7. Salmon eggs, preserved with 0.5 percent sodium disulfite and 

 stored at room temperatures for 3 months before being frozen, lost a 

 portion of their growth potential. 



8. Attempts to reduce mortality due to feeding 10 percent of salmon 

 meal during prolonged periods of cold water produced, in the main, nega- 

 tive results. Predigested salmon-viscera meal and the vacuum-dried 

 product fortified with h percent each of lysine and methionine did not 

 reduce the mortality, rather the predigested meal aggravated it. The 

 addition of B-complex vitamins to the diet caused a significant reductioQ 

 in the mortality, but the losses were still significantly higher than 

 those of the control lot. A 5 percent meal content in the diet caused a 

 significant increase in grovrth rate without an increase in mortality over 

 the control. A more complete vitamin supplementation may prove the key 

 to mortalities when high-protein diets are fed during periods of prolong- 

 ed cold water. 



9. In experiments with Chinook salmon it was impossible to demon- 

 strate a difference betv*reen the nutritional requirements of chinook and 

 blueback salmon. The standard meat-viscera mixture used for blueback 

 proved entirely adequate for chinook. The addition of 10 percent meal 

 to the Chinook diet (one third each of beef liver, hog liver, and salmon 

 viscera) resulted in a significant acceleration in growth rate with no 

 anemia when fed during the warm-water period. 



Acknowledgements 



Messrs. Halver and Goates of Western Fish Nutrition Investigations 

 of the U. 3. Fish and Wildlife Service offered material aid in the prepa- 

 ration of .the predigested meal used in the experiments and in the design 



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