Using this criterion, it was found that there was no significant 

 difference between the growth rates of the 3 salmon meals tested (Diets 

 3, 4, and 5) but that all these diets showed a rdghly significant difference 

 from the control (Diet 2). From these results it was concluded that dry 

 meals at the 10 percent level in the diet made a highly significant con- 

 tribution to the growth rate. These analyses leave no alternative but the 

 conclusion that the protein in fish meals prepared by these 3 processes is 

 not altered in such a manner as to make it unavailable to the fish. The 

 second conclusion, that intense heat has no effect on the growth poten- 

 tial of fish meals, is subject to further corroborative evidence. An addi- 

 tional variable, that of a different meal composition, was introduced into 

 Diet U and this may have a direct bearing on the results. Another factor, 

 the short term of the experimental period, may have obscured the signifi- 

 cauice of any differences that may exist between the low-temperature and 

 flame-dried meals. However, there can be no question but that flame-dried 

 salmon offal meal makes a significant contribution to the grcwth rate of 

 blueback salmon. 



Diet 6, salmon viscera and apple pomace, showed a significant difference 

 in weight when compared with Diet 2 and a highly significant difference 

 when compared with Diet 1. From these data it may be inferred that salmon 

 viscera contains an excellent growth potential and may be responsible for 

 the hi^ly significant difference in growth rate which exists in favor of 

 Diet 2 over Diet 1. 



The salmon waste from which the viscera had been removed (Diet 7) 

 showed no promise as a food for fingerling salmon when fed in the raw state. 

 The fish fed this diet showed the lowest rate of growth of any of the diets 

 tested. A highly significant difference existed between the mean weight of 

 the troughs fed salmon waste and that of the next lowest diet — the beef 

 liver control. When compared with salmon viscera the difference is startling. 



The conversion shown in Table 1 is the number of grams of food required 

 to produce a gram of fish weight. The ccxiversion factor serves as a measure 

 of the efficiency of a diet. If the conversion factor shows a specific 

 diet to be very efficient, the relatively high cost of one or more of the 

 ingredients of this diet would be perfectly acceptable by reason of the sig- 

 nificantly better gain per unit of feed consumed. On this basis the use of 

 salmon viscera and salmon meals are more than justified since these products 

 cost from 5 to 7 cents per pound as compared to an average cost of 10 cents 

 per pound for frozen meats and much more efficient conversions to fish 

 flesh result from the use of the salmon products. 



Sunmary 



The experimait was divided into two parts, (l) a survival experiment to 

 establish the presence or absence of the anti-anemia factors in salmon meals, 

 and (2) growth evaluations of five salmon waste products. Both phases were 

 conducted using blueback salmon fingerlings ( Oncorhynchus nerka) as the test 

 animals . 



58 



