when the food intake was high. The growth response to salmon eggs during 

 warm water periods exceeded that of the salmon viscera control fish. The 

 growth rate of the fish fed the other segments of the viscera was defin- 

 itely inferior to those fed the entire viscera. 



Salmon eggs in composite diets in which beef and hog liver were used 

 to supply vitamin fortification produced gains significantly greater than 

 those resulting from comparable diets including salmon viscera at water 

 tempera tTires above 50° F. 



Salmon eggs were preserved with sodium benzoate, sodium bisulfite, 

 salt, and various combinations of these three preservatives. Mo toxicity 

 to fish was demonstrated by any of the preservatives, although a destruc- 

 tion of thiamine was indicated. Growth of the fish when these eggs were 

 fed at the 90-percent level in the diet was significantly greater than 

 for any group fed the other types of preserved eggs tested and most nearly 

 approached that of the control group fed frozen salmon eggs. Adequate 

 fortification of diets with beef liver, hog liver, and hog spleen produced 

 gains in weight of fish fed a 30-percent level of sodium bisulfite pre- 

 served eggs ccmparable to those fed the same level of frozen salmon eggs. 

 These evaluations were preliminary in nature due to the fact that the 

 toxicity of the chemicals rather than tne effect of prolonged preservation 

 was luider investigation. 



Salmon milt was fovmd to be an excellent binding agent when mixed 

 with salt. Its binding quality was approximately twice that of hog spleen. 

 Vftien used at the 10 -percent level in composite diets, the feeding consist- 

 ency of the ration was excellent. Salmon milt at the 10-percent level in 

 combination with beef liver, hog liver, aJid salmon viscera produced 

 excellent growth and low mortality. In a similar combination with salmon 

 eggs substituted for viscera there was a significant increase in mortality 

 during cold water feeding. 



Salmon Carcass 



The carcasses of spawned out salmon when fed in conjunction with beef 

 and hog liver, and hog spleen, produced a growth rate inferior to cca^r- 

 able diets in which salmon viscera was substituted. Salmon carcasses were 

 deficient in the anti-anemic factor as well as other essential vitamins. 

 There were indications that the salmon carcasses contained at least awflil 

 amounts of thiaminase. Although the growth response with a diet of 30- 

 percent carcasses was less than that with an equal quantity of viscera, it 

 still has possibilities in hatchery diets. Because of the presence of 

 thiaminase and its deficiency in the anti-aneanic factor, salmon carcasses 

 must be adequately fortified in composite diets and fed with caution. 



Canned Salmon 



Condemned (unfit for human consumption) canned salmon did not compare 

 favorably with salmon viscera when included at levels of 45 percent or over 



47 



