The resialts of previous experiments showed that hake could be used 

 as a substitute for hog spleen in the meat-viscera diet during either period 

 of water temperature. The results of this experiment also showed that either 

 hog spleen or halibut sax;Hust produced greater growth than hake in t he meat- 

 viscera-meal diet. The comparisons in this experiment of the different com- 

 ponents, such as salmon eggs, salmon milt, and salmon waste meal with a hake, 

 beef liver and hog liver base, indicated that hake was compatible with these 

 componpirt-^ 



Whole Cod 



Whole cod ( Gadus macrocephalus )^ ordinarily considered as a food 

 for humans J also may be considered as a possible fish food because of the ex- 

 tremely low market price of cod in the round. 



liilhole cod was tested in a singly component diet. Diet 1;!, against 

 the beef liver control, Diet 19^ and against halibut sawdust. Diet 1|3. It 

 was also tested as a component of the neat-viscera-neal cor.,binaticn by sub- 

 stituting whole cod for hog spleen to make Diet i;2. Whole cod in this com- 

 bina^on may be compared with hog spleen in Diet h6, halibut sawdust in Diet 

 U3, and hbke in ^iet 35 since all of these diets have the same base. 



As a single component, whole cod did not produce as much weight as 

 either beef liver or halibut sawdust (Table 2, Diets hi, 19 and i;3). The 

 differences were significant. As a component of the meat-viscera-meal com- 

 bination in Diet 1(2, whole cod proved to be inferior to hog spleen or hali- 

 but sawdust (Table 2, Diets U2, UIi, and U6), Whole cod was the equal of hake, 

 however, as shown by the lack of difference in mean lot weights between 

 Diets Ul and 35. 



From these results, vhole cod, as a growth producer in the meat- 

 viscera-meal combination, may be rated inferior to halibut sawdust and hog 

 ' spleen but equal to hake. 



Halibut Sawdust 



Halibut sawdust is the band saw waste resulting from the preparation 



of halibut (Hipnoglossus stenolepis) for human consumption. The quantity of 

 this by-product is not great, but i)0,000 pounds are annually available in 

 this Seattle area at a very nominal cost. 



The experiment with halibut sawdust, similar to the previous ex- 

 periment with wh-ole cod, tested halibut sawdust as a single component. Diet 

 h3s and as a component of the meat-viscera-meal combination. Diet kh' 



As a single component, halibut sawdust provided gains that were not 

 significantly different than beef liver (Table 2, Diets h3 and 19), but were 

 significantly greater than those provided by whole cod (Table 2, ^-'iets ii3 and 

 hX) " As a component of the meat-viscera-meal combination, halibut sawdust 



17 



