FURTHER STUDIES ON PROTEIN AND CALORIE LEVELS OF 

 MEAT-MEAL, VITAMIN SUPPLEMENTED SALMON DIETS 



BY 



Laurie G. Fowler, J. Howard McCormick, Jr. 

 and Allan E. Thomas, Fishery Biologists (Research) 



ABSTRACT 



Feeding trials were conducted with fingerlings of fall chinook salmon (Oncorhynchus 

 tsha.vytscha) to determine the effect of feeding three protein levels, four caloric levels, 

 crystalline vitamins, and meat supplements in a basic meal mixture. After 24 weeks of 

 feeding the results were as follows: 



Fish fed at a protein intake of 27.5 percent produced significantly higher protein 

 deposition than did fish fed at protein intakes of 25 and 20 percent, but tended to be less 

 efficient as measured by protein utilization. 



Addition of supplemental energy calories in the diets resulted in a sparing action 

 on the protein and vitamin requirements of the fish. The energy requirement of the 

 fish increased, in proportion to the protein requirement, as the fish increased in size. 



A crystalline vitamin supplement was inadequate when fed in diets containing a 

 meat supplement . 



Meat supplementation ranging from 10 to 50 percent of the meat-meal combination 

 produced no measurable differences in mortality, average weight, protein deposition, 

 or protein utilization. 



An all -meal diet produced fish with gains, protein deposition, protein utilization, 

 performances , and general condition as good as or better than fish in comparable 

 diets fed meat supplements . 



Feeding trials conducted at the Salmon- 

 Cultural Laboratory, Longview, Washington, 

 in 1962, were a continuation and enlargement 

 of experiments reported by Combs et al. (1962). 

 Fingerlings of fall chinook salmon (Oncorhyn- 

 chus tshawytscha) were used as the test ani- 

 mals . The primary purpose of these and the 

 previous trials was the development of nutri- 

 tionally adequate and economically feasible 

 diets for the artificial propagation of salmon . 



The experiments were directed toward 

 exploring the effect of several protein levels , 

 caloric intakes, and meat and vitamin supple- 



mentation when fed in a single basic meal ration. 

 The composite-meal, basal ration was fed with 

 a meat supplement ranging in amounts from 10 

 to 50 percent of the total mixture and with or 

 without a complete vitamin supplement . The 

 level of protein intake was controlled by partial 

 reconstruction of the diet with water by the 

 method developed by Phillips and Brockway 

 (1959), and the level of calories was increased 

 when desired by the addition of peanut oil. 

 With this technique it was possible to determine 

 the effect of energy calorie supplementation at 

 several fixed levels of protein intake . 



