84 American Fisheries Society 



but I want to say that as far as my experience has gone it is a mighty good 

 thing to use fish to some extent as fish food. With a part fish diet you get 

 a better quality of fish and a stronger fish than if you feed entirely on liver 

 and melts. 



Mr. G. C. Leach, of the U. S. Bureau of Fisheries: I notice nothing has 

 been said in the discussions about beef heart. In the middle west, beef 

 heart usually sells for twenty to thirty per cent cheaper than beef liver, 

 and it has been considered that in protein content it is fifty per cent greater 

 than beef liver. In making up contracts with the packing houses, if it is 

 specified that they must trim the beef liver of all gristle and fat, the fish 

 culturist does not have much to eliminate, and that part that he does have 

 to cut out can be fed to the adult fish. All the better portion of it can be 

 passed through the meat grinder several times, using a very fine plate, and 

 fed to the fry. I have found that it is preferable to the beef liver, because 

 the liver, when ground very fine, disintegrates into a liquid and a fibrous 

 substance, either of which may cause mortality in the trout. The beef 

 heart grinds in very fine particles and the fry get something that does them 

 some good; so, for that reason, out in the middle west we have been feeding 

 beef heart when we could get it, and it has always given very good 

 satisfaction. 



In the middle west, also, we feed to our larger fish various gross fish, 

 such as the gissard shad, and cat-fish, perhaps a little off the mark, and 

 purchased for about six cents a pound. That diet is very good for adult 

 fish, but when ground through the smaller plates it disintegrates and I 

 doubt if it is very good for small fish unless fed with some carbo-hydrate. 

 But for the larger fish I believe it produces a better egg and is more of a 

 natural fish food, especially for trout. 



Professor E. E. Prince, of Ottawa, Canada: I think it is desirable in 

 selecting food always to look at the character of the natural food of the fish. 

 The trout are great insect feeders in the fresh water, and anything that cor- 

 responds to the physical character of this insect food ought to be good. 

 Ground up shrimps of course would correspond to the food they get in the 

 salt water. Fish itself would correspond to the various species of fish on 

 which trout and salmon no doubt live to some extent in fresh water, but I 

 have always felt that the large internal organs of mammals, like liver, 

 lungs, etc., do not quite correspond to anything in the natural food of these 

 fish, and therefore it would be wise to combine other elements with this 

 ground lung and liver in order to provide a concentrated food. 



There is no doubt that fish fed with very concentrated food are apt to 

 have digestive troubles. The digestive canal is prepared to deal with a 

 certain amount of waste, and if there is no waste to the food, indigestion is 

 apt to occur. Consequently, it is a good thing to put in more fresh material 

 along with the fish, or shrimp powder, or whatever it may be, in order to 

 give the intestines some work to do. 



You may have noticed in the Canadian reports that coarse fish ground 

 up was used, years ago, for feeding the young fingerling salmon, and it was 



