over a similar diet without the meal. The addition o f vitamins to the meal 

 supplement reduced the mortality to the equivalent of the nonmeal diet. 



2. Continuation of a $ percent meal diet for 2it weeks produced growth 

 equal to the control diet fed for 12 weeks with no meal followed by 12 weeks 

 of 10 percent meal. The mortality in each case was similar. The control 

 diet, however, proved the most economical. 



3. Four commercial meals were compared with vacuum-dried salmon-viscera 

 meal as supplements during the warm-water period. Whale meal and wheat 

 middlings were inferior to salmon-viscera meal. Seal meal and distillers 

 solubles were comparable to salmon-viscera meal. 



U. Beef lung substituted for hog spleen in the standard control diet 

 produced less growth, although previously the growth had been equal. The 

 higher fat content of the spleen used in this trial was assumed to account 

 for the difference. 



5. Herring, fed in combination with hog liver, beef lung, and salmon 

 viscera, and with beef lung and salmon viscera, produced heavy mortalities 

 caused by an inadequate thiamin content in the diet, insufficient to combat 

 the thiaminase present in the herring. 



6. Arrow-toothed halibut, when substituted for beef liver in the 

 beef -lung variation of the control diet and hog liver in the hog liver 

 beef lung salmon viscera combination produced comparable growth rates and 

 no deficiency symptoms. Both combinations utilizing halibut are highly 

 recommended for production feeding. 



SUMMARY OF RESULTS— CHINOOK SALMON 



The results of the 1952 feeding trials utilizing fingerling chinook 

 salmon as the test animals are summarized as follows: 



1. The standard control ration consisting of beef liver, hog liver, 

 hog spleen, and salmon viscera when f ed to chinook did not differ from 

 the beef liver, hog liver, and salmon viscera diet. 



2. Substitution o f beef lung for hog spleen in the standard control 

 diet reduced the growth rate of chinook salmon as it did that of blueback 

 salmon. The higher fat content of the spleen used in these trials was 

 assumed to account for the difference. 



3. Herring substituted for spleen in the standard control diet showed 

 no evidence of a thi amine deficiency and produced growth rates equal to 

 spleen. 



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