combination. The composite meal consisted of 

 35 percent vacuum -dried salmon carcass meal, 

 30 percent dried skim milk, 20 percent cotton- 

 seed meal, and 15 percent wheat germ . The 

 meat mixture fed in combination with the com- 

 posite meal consisted of 50 percent each of beef 

 liver and hog liver. The composition of the 

 diets and the vitamin supplement are given in 

 table 1 . The ingredients of the basic mixtures 

 and their proximate analyses are shown in table 

 lA. 



growth since total gain includes fat deposition 

 which is not considered to be true growth 

 (Gerking. 1955; Phillips, elal.., 1956). Protein 

 utilization, a measure of the efficiency of a diet 

 for growth production, was calculated by divid- 

 ing the amount of protein fed by the amount of 

 protein deposited in the fish. In order to com- 

 pensate for the high mortalities sustained in all 

 groups, calculation of protein and fat deposition 

 was based on average weight per diet corrected 

 for mortality. 



A vitamin supplement containing the water 

 soluble vitamins essential for chinook salmon, 

 as determined by Halver (1957), was included in 

 one series of diets. High -viscosity CMC (car- 

 boxymethyl cellulose) was used as a carrier for 

 the vitamins and as a diet binding agent. The 

 composition of the vitamin mixture was such that 

 0.5 gram per kilogram of fish weight per day was 

 sufficient to provide for maximum storage (Halver 

 et al. 1960). Additional CMC was added to the 

 rations to provide two grams per 100 grams of 

 diet. The composition of the vitamin supplement 

 fed is presented in table IB. 



6 . Ettets containing high levels of dry 

 meals required a different mixing technique than 

 that usually employed for rations composed 

 principally of meats. The dry ingredients in- 

 cluding meals, vitamin mixture, salt, and CMC 

 were pre -mixed to insure homogeneity. The 

 meat and meal components were then mixed to- 

 gether with measured amounts of water to pro- 

 duce mush -type diets similar in consistency to 

 meat diets. 



7 . The feeding trials were intended \o 

 continue for a 24 -week period; however, due to 

 high mortalities they were discontinued after 14 

 weeks. The cercariae of the digenetic trematode 

 Nanophyetus salmincola which were prevalent in 

 Abernathy Creek were believed to be the prin- 

 ciple cause of the mortality. Data included in 

 this report were compiled after 12 weeks of 

 feeding before losses became excessive. 



8 . The chemical composition of the fish, 

 as determined by proximate analysis, was the 

 criterion used for analyzing the results of the 

 experiments. Protein deposition instead of 

 total gain in weight was used as the measure of 



RESULTS OF EXPERIMENTS 



The test diets included a standard control 

 and 20 experimental diets which were designed 

 to measure the effect of four levels of meat 

 supplementation, the addition of a vitaniin sup- 

 plement, two protein levels, and three calorie 

 levels. A summary of the results of the experi- 

 ments is presented in table 2. All of the experi- 

 mental diets produced gains comparable to or 

 exceeding that produced by the control diet. The 

 control has been fed on a production basis at 

 Entiat for several years and at Longview during 

 1961 with excellent results. 



Effect of Meat and Vitamin Supplementation 



Diets containing the lowest level of meat 

 supplementation, a ratio of 10 parts meat to 90 

 parts meal, proved adequate in maintaining the 

 fish. The vitamin supplement fed had no mea- 

 surable effect on growth or mortality. The com- 

 posite meal fed was apparently of higji value for 

 Chinook salmon since calculation of vitamin con- 

 tent had revealed possible deficiencies in certain 

 of the low meat-hig^ meal diets. However, 

 since the rearing tanks were outside and were 

 supplied with creek water during most of the 

 experimental period, the contribution of natural 

 food may have been sufficient to fortify marginal 

 diets. 



Effect of Protein Levels 



The 25 percent protein diets produced 

 significantly more weight and greater protein 

 deposition than comparable diets fed at the 20 

 percent level. There was a trend toward greater 

 protein deposition and more efficient protein 

 utilization in the groups fed the diets containing 



