the higher proportions of meat indicating the 

 possibility that the protein quality of the meat 

 was superior to that of the meal for chinook 

 salmon. 



Effect of Caloric Levels 



Peanut oil was added to four diets fed at 

 the 20 percent protein level to determine the 

 effect of increased caloric intake on protein de- 

 position and utilization and on fat deposition. 

 Diets 7, 18, and 20 were each fed at a meat- 

 meal ratio of 30:70 with caloric levels of 1300, 

 1650, and 2000 calories per kilogram respec- 

 tively. The caloric level was increased in diets 

 18 and 20 by substituting peanut oil for a portion 

 of the water in the mixed rations. Diets 9, 19, 

 and 21 were fed at a meat-meal ratio of 10:90 

 and at caloric levels corresponding to 7, 18, 

 and 20. 



Protein deposition and utilization: --An 

 increase in caloric level from 1300 to 1650 

 calories per kilogram in 20 percent protein 

 diets resulted in greater protein deposition and 

 more efficient protein utilization. The addition- 

 al calories supplied by the peanut oil were ap- 

 parently utilized to meet, at least partially, the 

 energy requirement of the fish, thereby sparing 

 the protein. These results concur with those 

 of Phillips et al. (1961) who reported that in 

 feeding trials with trout, diets which contained 

 cod liver oil produced more growth than com- 

 parable diets fed without oil. Diet composition 

 may be an important factor influencing the util- 

 ization of lipids for energy since Buhler and 

 Halver (1961) reported decreased protein effi- 

 ciency and an inhibition in fish growth when 

 dextrin was isocalorically replaced with corn 

 oil in semi -synthetic diets fed chinook salmon. 



Fat deposition and protein calorie to 

 energy calorie relationship:- -A further in- 

 crease in caloric level from 1650 to 2000 

 calories per kilogram did not increase protein 

 deposition or protein efficiency but increased 

 fat deposition in the fish fed the 2000 calories 

 diet at the 30:70 meat-meal ratio. A caloric 

 level of 1650 calories per kilogram with a pro- 

 tein calorie to energy calorie ratio of 1:1 appears 

 to be near optimum in the 20 percent protein 

 diets tested. The fish fed the 2000 calorie diet 



at the 10:90 meat-meal ratio contained a fat 

 deposit significantly less than that of the fish 

 fed at the 1650 calorie level . It is considered 

 likely that the fish withdrawn for analysis from 

 the 2000 calorie group were not a representative 

 sample . 



SUN4MARY 



The results of the 1961 feeding trials 

 with fall chinook salmon fingerlings may be 

 summarized as follows: 



1 . Experimental diets consisting of a 

 composite meal supplemented with meats pro- 

 duced gains equal to or exceeding those pro- 

 duced by a standard production control diet. 



2 . A ratio of only 10 parts meat to 90 

 parts of the composite meal in mixed diets 

 proved adequate for maintaining chinook salmon 

 fingerlings . 



3 . A synthetic vitamin supplement had 

 no measurable effect on either growth or 

 survival under the conditions of the experiment. 



4. Diets fed at the 25 percent protein 

 level produced significantly greater gain in 

 weight and higher protein deposition than com- 

 parable diets fed at the 20 percent protein level . 



5. An increase in caloric level from 1300 

 to 1650 calories per kilogram in 20 percent 

 protein diets resulted in significantly greater 

 gain, higher protein deposition, and more ef- 

 ficient protein utilization . A sparing action on 

 the protein by the addition of energy calories 



as peanut oil is indicated. 



6. Increasing the caloric level to 2000 

 calories per kilogram in 20 percent protein 

 diets did not produce either greater protein 

 deposition or increased protein efficiency above 

 that of comparable 1650 calorie diets. A pro- 

 tein calorie to energy calorie ratio of 1:1 is 

 indicated to be near optimum in the 20 percent 

 protein diets tested. 



