meals were tested; some were prepared from Columbia Hiver-Chinook salmon 

 viscera and others from Alaskan pink salnon viscera and Alaskan pink 

 salmon offal. In addition, a meal prepared from a purposely spoiled or 

 deccmposed pink salmon offal and a commercially manufactured flame-dried 

 salmon olfal meal were evaluated. The nutritive values of raw cannery 

 wastes and diet mixtures containing these wastes, were compared with 

 diet mixtures containing beef liver, hog liver, and hog spleen. Proxi- 

 mate compositicai was determined on 21 different diet components. A 

 discussion and summary of these data was presented in a report (Karrick 

 and Edwards 1948) entitled, "Utilization of Alaska Salmon Cannery Waste - 

 Vitamin Content of Experimental Fish Hatchery Foods," Office of Tech- 

 nical Services Report, Part Two, Section Three, Department of Commerce, 

 Cac -47-17, December, 1948. 



It was found (Burrows, Robinson, and Palmer l95l) that the low- 

 temperature tunnel-dried saimon viscera meal fed as 10 percent of the 

 diet increased the growth rate of salmon fingerlings considerably above 

 that produced by feeding flame-dried salmon offal meal. Temperature of 

 meal preparation also proved to be important since the viscera meal 

 dried at 100° F. stimulated greater growth than did a similar meal dried 

 at a temperature of 145° F. It was also observed dviring these experi- 

 mental feeding trials that dried fish meals added to the diet at water 

 temperatures below 50° F. or before the fish had been feeding for 6 weeks 

 increased the mortality rate and actually retarded growth. After 6 weeks 

 on test and at water temperatures above 50° F. the addition of viscera 

 meals to the diet produced significantly greater growth in the fingerlings 

 than was produced by feeding the regular control diets. 



The 1949 program 



Resvtlts of the 1947 and 1948 feeding trials indicated that salmon 

 viscera can be used to replace part of the meat gland products usually 

 incorporated in the diet, with a definite increase in growth rate as 

 well as affecting a considerable saving in the cost of the food items. 

 During 1949* experiments were set up to determine the contribution to 

 increased growth made by each of the various segregated portions of 

 salmon viscera which are composed of roe, milt, digestive tract, and 

 liver. Evaluation studies were also made on yellowfin tuna liver and on 

 Dungeness crab waste meal. Tuna livers had become available for hatchery 

 feeding due to a reduced demand for the livers for vitamin A production. 

 Crab meal had shown some promise as fish food in nutritional studies 

 carried out by McClaren, Herman, and Elvehjem (1947). Simultaneously, 

 a chemical and vitamin study of raw livers, and liver meals of beef, 

 yellowfin tuna, and albacore t\ina prepared by steam-neated vacuum 

 drying, lyo]^iliaing, (freeze-drying), and acetone extraction was 

 carried out by Jones and Hoyer (1950) at the Fishery Technological 

 Laboratory in Seattle. It was hoped that information concerning liver 

 meals might lead to their subsequent use as a replacement for {>art or all 

 of the raw beef liver customarily included in the salmon diets. 



