In the 1951 trials, addition of the B-complex vitamins to the diet 

 caused a significant reduction in the mortality although the losses were 

 still significantly higher than those of the control diet. The addition 

 of all of the major vitamins in the 1952 trials caused a significant 

 reduction in the mortality, and the losses were comparable to those of 

 the control . These results indicate that a relation exists between colder 

 water temperatures and the utilization of, or demand for, vitamins in meal 

 supplements. 



The diets in which 10 percent meal was fed during the first 12 weeks 

 (Diets 3 and h) were discontinued at the close of the cold-water period. 

 The 5 percent meal supplement was continued during the warm-water period. 



A comparison was made between fish fed no meal at cold water and 10 

 percent meal in warm water (Diet 2) and fish fed 5 percent meal during the 

 entire 2li-week period (Diet 5). Mean weights at 12 weeks tended to be in 

 favor of the 5 percent meal diet, though not significantly so. This trend 

 was reversed during the warm-water period, but again a significant difference 

 was not attained* The overall gain (i+5l#) made during the second period by 

 the Diet 2 fish was greater than the gain (bl5%) made by the Diet 5 fish. 

 Diet 2 was more economical because during the period of greatest growth it 

 received 10 percent meal (amounting to 536 grams) as against 5 percent meal 

 (322 grams) in Diet 5 during the same period. The small amount of meal used 

 at 5 percent (50 grams) during the cold-water period did not appreciably 

 increase the total amount of meal used in Diet 5. 



Meal Evaluations 



Four commercial meals were tested in this series in comparison with 

 vacuum-dried salmon viscera meal and in combination with the standard 

 meat-viscera mixture. These meals were whale meal, wheat middlings, 

 seal meal, and distillers solubles. The diets in the meal supplementation 

 trials consisted of the meat-viscera combination for 12 weeks followed by 

 supplementation with the respective meals at the 10-percent level during 

 the last 12-week period. The fish fed wheat middlings (Diet 7) showed the 

 least growth r esponse; they were exceeded significantly by fish fed whale 

 meal (Diet 6). Whale meal was inferior to both seal meal (Diet 8) and dis- 

 tillers solubles (Diet 9), both of which, on the basis of mean weights, were 

 comparable to the salmon -vise era meal (Diet 2). Both seal meal and dis- 

 tillers solubles are recommended as dry-meal supplements for periods of warm- 

 water feeding. 



Potential Production Diets 



The goal of these feeding trials was to find combinations of relatively 

 inexpensive fish and meats that would produce healthy, fast-growing fish. 

 The blueback production diet (Diet 2) has proved a somewhat expensive diet 

 because of the two components, beef liver and hog spleen. In Diet 10, hog 



