viscera meal or salmon offal meal, -further use of crab meal in ex- 

 periments seem to be warranted, since these trials revealed that crab 

 meal has several advanta;::es not found in salmon meals when fed at tem- 

 peratures averaging U5° F. 



RECOMMENDED PRODUCTION DIETS FOR BLUEB/lCK SALMON 



The requirements of a diet suitable for production purposes should 

 be as follows: good growth, low conversion rate, low mortality, and 

 no discernible sjnnptoms of nutritional deficiencies c The diets in this 

 experiment that most fully meet these requirements during periods of 

 cold-water are Diets 13 and lU (Table 1) which are composed of a meat- 

 viscera mixture of 22.2 per cent each of beef liver, hog liver, hog 

 spleen , and 33»1| per cent salmon viscera. When warm-water prevailed, 

 ■^iet 111 proved superior to Diet 13 C^^^^le 3). Diet lb during the wirm- 

 water period, consisted of tie preceding -neal-viscera mixture at the 

 rate of 90 per cent and salmon viscera meals at the rate of 10 per 

 cent. Although the meal used with Diet lb was a 100° tunnel-dried 

 salmon viscera meal, other salmon waste meals could have been used 

 with satisfactory results. The best results from a meal probably 

 would be obtained with vacuum-dried salmon viscera meal (Table k) » 



If the hog spleen in this production diet is unavailable or too 

 expensive, hake, which is much less costly, may be substituted (TaMe 



5). 



The hog liver-salmon viscera combination, although not showing 

 up as well as the recommended diet in this experiment, nevertheless has 

 possibilities of being a satisfactory diet for blueback during warm- 

 water periods (Table 1, Diets 5, 6, and 7) . If a meal is used with 

 this combination, crab meal or a combination of crab meal and salmon 

 meal should be used and not one of the salmon meals alone. Beef liver' 

 could be add^d to supplement this diet, if necessary (Table 1, -Diet 9), 



•^'or other possible diets or substitutions in the recommended 

 diets, see Burrows etal. (195l). 



SUMR^UIY 



With these particular diets and using blueback salmon as the 

 test animal, the summary of results is as follows: 



1. Tuna liver as the sole component of a diet produced a low 

 growth rate, a high mortality'' rate, numerous dieficiency symptoms, but 

 no anemia. 



2. Of the various segments of salmon viscera, salmon eggs produced 



18 



