seaboard but according to Atkins (I9O8) and Titconb et al. (1929) the 

 results were not conclusive. Frozen herring in the round is a cheap 

 available source of fish food on the Pacific coast. 



The first group of diets in the second experiment were single com- 

 ponent rations. In these studies the intent was to measure the poten- 

 tialities of the individual products not for use as production diets but 

 as possible supplements to other combinations. Whale liver (Diet 20), 

 arrow-toothed halibut (Diet 21), and herring (Diet 22) were fed as 

 unsupplemented rations for comparison with beef liver (Diet 19)- The 

 whale-liver diet vtas discontinued after U weeks due to a high mortality. 

 It was indicated that this toxic effect was produced hj an excess of 

 vitamin A in the whale liver. Both arrow-toothed halibut and herring 

 proved to have a higher growth potential than beef liver with herring 

 being superior to halibut. In the herring-fed fish, symptoms of a 

 thiamin deficiency were discernible after 6 weeks of feeding and were 

 very pronounced at the conclusion of the experiment. No such symptoms 

 occurred in the fish fed the arrow-toothed halibut. 



In the second group of trials various substitutions were made in 

 the standard meat-vis cera-meal mixture. In Diet 2U whale meal was 

 substituted for salmon viscera meal. This whale meal was an especially- 

 prepared, low-temperature-dried product supplied by the Seattle Techno- 

 logical Laboratory of the Fish and Wildlife Service. The growth response 

 of the fish on the diet containing whale meal was comparable to that of 

 those fed salmon viscera meal. Whale meal appeared to be an adequate 

 substitute for Sctlmon viscera meal. Because of the growth stimulus 

 supplied by the lov/-temperature-dried whale meal it is proposed to test 

 a commercially-prepared, flame-dried whale meal next season. 



Whale liver (Diet 2^) substituted for beef liver in the raeat- 

 viscera-meal mixture produced an adequate diet when fed for a 12-week 

 period. The grovj-th rate was comparable to the control (Diet 23) and no 

 anemia was indicated. Because of the results of the single component 

 studies, however, in which v;hale liver produced an acute toxicity, it 

 is doubtful if vihale liver would be a safe product to include in pro- 

 duction diets. 



Beef lung was substituted for hog spleen in Diet 26. This substi- 

 tution was based on the results of the 12-week period of the first 

 experiment. The growth rate on this diet was practically identical to 

 that of the fish fed the control diet. The mortalities v/ere not signi- 

 ficantly different and the hemoglobin content of the blood was comparable. 

 If anything the bound quality of this diet was better than that of the 

 control. Because of its cheaper price and equal nutritional adequacy, 

 the substitution of beef lung for hog spleen in the meat-vis cera-meal 

 mixture can be recommended. 



Previous experiments with ocean fish sbustituted for various products 

 in the meat-viscera-meal mixture indicated that the deletion of spleen 



lU 



