TESTS OF HATCHERY FOODS FOR SALMON, 1952 



The feeding trials conducted in 1952 at the Entiat Salmon-Cultural 

 Laboratory were a continuation of feeding e xperiraents conducted annually 

 since 19u4 (Burrows et al. 1951, Robinson et al. 195la, Robinson et al. 

 195lb, and Burrows et al. 1952) . Both blueback salmon ( Oncorhynchus nerka) 

 and chinook salmon J5. tshawytscha ) were used as the test animals. 



Two experiments were run simultaneously, each for a 12-week cold-water 

 period followed by a 12-week warm-water period, with the exception that two 

 of the diets in the first experiment were tested under the cold-water condi- 

 tions only. 



The first experiment, utilizing blueback salmon fingerlings, contained 

 the following tests: (1) dry meal toxicity tests in which vitamin supple- 

 mentation reduced the mortality, (2) meal e valuations wherein two meals were 

 found to be comparable to the control, and (3) potential production diets 

 composed of two different groups. Substitutions in the standard blueback 

 diet to avoid the use of beef liver and hog spleen comprised one group; the 

 other was a series utilizing a 50 percent salmon viscera base and various 

 combinations of meat and fish products. A good production diet resulted 

 from each group. 



The second experiment, using chinook salmon fingerlings, embodied a 

 retesting of combinations already found practicable as food for blueback 

 salmon fingerlings. Four of the best meat-viscera mixtures of the 1951 

 trials with blueback salmonwere compared with the standard chinook ration. 

 These tests provided an additional comparison of the requirements of chinook 

 and blueback salmon which were found to be similar in 1951. 



CONDITIONS OF EXPERIMENT 



In the first experiment 30 troughs were stocked with 500 grams each 

 of fingerling blueback salmon at an average size of 1,236 fish per pound. 

 Sample troughs were counted and found to average 1,36] fish each. 



The fingerling chinook salmon used in the second experiment averaged 

 27a per pound. They were stocked into 6-foot circular tanks at 1,000 

 grams per tank. Counts made in the tanks showed an average of 603 fish per 

 tank. 



During the cold-water phase of the experiments the average water 

 temperature was hh-9° F. Daily temperatures fluctuated greatly in the 

 second 12-week phase with an average water temperature of 5o.u* F. 



The techniques, equipment, and methods used were the same as described 

 by Burrows et al. (1951 and 1952). 



