256 American Fisheries Society 



Discussion 



Mr. John W. Titcomb, Albany, N. Y. : Would it not be possible 

 to get these same comparisons between different species at the same age? 



Mr. Hayford: It would be possible, but the difference is in the 

 weight. 



Mr. Titcomb: In comparing the growth of these different species, 

 did you get a record of the weight of different kinds of food used? 



Mr. Hayford: We gave each species one-fiftieth of its weight 

 daily, divided into two foods. It might be possible to use a cheaper food 

 and more of it. This is a matter that requires a good deal of considera- 

 tion because under different temperatures it works differently. What 

 might be good at 51 degrees might work differently at another 

 temperature. 



Mr. Titcomb: Do I understand you to say that in feeding you 

 used sheep plucks and livers ground together? 



Mr. Hayford : Yes, all ground together. The best results were 

 obtained from the beef liver and maggots in the case of the brook 

 trout, and from the sheep plucks in the case of the brown trout. 



Mr. Titcomb: I suggest that anyone who wants to carry this test 

 along with the maggots produced from fish will find that it is a very 

 much less offensive operation than producing maggots from meat. It 

 is a very simple matter to produce tons of maggots from cold storage 

 fish, and the odor does not extend very far beyond the building where 

 they are produced. In connection with our fish-cultural operations we 

 catch a great many carp and bill fish. They are placed in cold storage 

 and eventually taken to one of the game farms and changed into 

 maggots for feeding the pheasants. Every particle of the fish is used 

 except the skin and the bones. It is a very simple process. 



