however, is indicated to be leas than that of beef liver. When 

 fed in conjunction with other products which are deficient in 

 this factor, salmon viscera does not. nrovide adequate fortificatj 

 Equal parts of hog liver and salmon viscera in combination with 20 

 per cent salmon viscera meal did not prevent an anemia from developing 

 in blueback salmon during a 2u-week experimental period (Table 5, 

 Diet 6)„ Both salmon viscera and hog liver contain the anti-anemic 

 factor but not in sufficient quantity to fortify the high level of 

 meal used in the diet. Salmon viscera at the 50 per cent level 

 when fed with U0 per cent hake and 10 per cent meal resulted in an 

 anemic condition in the fish at the close of the experiment (Table $ 3 

 Diet7)„ Hake is known to be deficient in the anti-anemic factor but, 

 according to Wales (19 Ui), the addition of £0 per cent beef liver" 

 to a diet of ocean fish consisting principally of hake produced an 

 adequate diet for trout. Because the substitution of salmon viscera 

 for beef liver produced an anemia it may be concluded that salmon viscera 

 does not contain amounts of the antianemic factor comparable to beef 

 liver. 



The results of these feeding trials indicate that salmon viscera 

 produces an excellent growth response in blueback salmon, superior to 

 any meat product tested, but is a less potent source of the anti-anemic 

 factor than is beef liver and contains but minimal amounts of panto- 

 thenic acid, sufficient only to support blueback salmon when the food 

 intake is high, Salmon viscera, therefore, should be fed in con- 

 junction with other products which will supply adequate vitamin for- 

 tification, particularly during periods of low water temperature. 



Salmon Offal 



Salmon viscera represents but 30 per cent of the entire salmon 

 offal. The remainder, consisting of the heads, collars, tails, and 

 fins, represents a large potential source of fish food. Two feeding 

 trials were conducted to evaluate this material. In the first trial, 

 salmon trimmings, the offal from which the viscera was excluded, were 

 fed at the 100 per cent level (Table h, Diet 13). The growth rate on. this 

 diet was very poor and the fish showed an acute anemia at tl e con- 

 clusion of the 12-week, experimental period. In the second trial, the 

 entire offal, in conjunction with 10 per cent, salmon viscera meal, was 

 fed (Table $, Diet 17). At the end of 10 weeks the experiment was dis- 

 continued due to an excessive mortal! ty„ Although the fish were not 

 anemic there were pronounced symptoms of a pantothenic acid deficiency. 

 The growth rate on this ration was very low— one of the poorest tested 

 during the I9U8 season. By deduction it may be concluded that the 

 factor responsible for the reduced growth rate in the entire salmon 

 offal was the salmon trimmings. 



18 



