2t) DEPARTMENT OF CiAME AND FISHERIES No. 9 



calculated and by taking the total increase in weight per 100 fish for the duration 

 of the experiment and dividing it into the total amount of food fed per 100 fish 

 the number of grams (or pounds) of food required to produce one gram (or pound) 

 increase in weight of the fish was determined. This figure is called the 'eflBciency 

 factor.' Naturally, the lower this figure is, the more eflBcient the food. 



Summarizing the details of the experiment we have the following results: 



1. Diets 3a and 3b cannot be considered since, after feeding for a period of 132 

 days the fish began to die from an intestinal disorder which could only be 

 blamed on the diet. 



2. Diet No. 4 cannot truly be compared with the other diets of group A, since 

 rainbow trout were fed, whereas the other diets of the group were fed to 



speckled trout. A different growth rate would be expected. However, it should 

 be stated that these fish progressed in health and weight very satisfactorily and 

 there was every reason to believe that the diet was a good one. 



3. Diets 2a and 2b excelled diet No. 1, namely the liver control, as shown in the 

 following table: 



Ck)st for one pound increase in fish weight 

 Diet No. Diets 2a and 2b Liver Control for same 



and 2a+2b Period 



2 a 62.5c 84.0c 



2 b 69.2c 107.1c 



2a+2b 67.4 95.5c 



4. In Grroup B the diets appear in the following order from the standpoint of 

 economy, namely, 8, It), 7, 9, 6, and 5 (liver control). 



5. In Group C diet 13a is the only one that showed any improvement over the liver 

 control diet No. 14. The addition of salmon egg meal to this diet apparently 

 proved uneconomical in this case. 



6. Diet 2 appears to have excellent possibilities as an economical trout food. In 

 view of the absence of suitable refrigeration facilities, at trout rearing stations, 

 the use of raw fish products as food, during the summer months, is surrounded 



by many practical difficulties. During the winter, this difiiculty can be over- 

 come to a considerable extent, but there is the additional difficulty of keeping 

 the fish in a wholesome condition for long periods. Processing the whole fish 

 into a meal is a practical way of handling this food, and obviates the 

 possibility of transferring fish parasites in the raw fish food. We have had 

 several tons of alewives processed and found the meal mixed with raw beef liver 

 equally as good as the fresh fish. The question of drying the fish has been 

 considered, but this method has not been used to date, for the reason that 

 quantities of alewives were difficult to obtain during that period when air drying 

 would be most practicable. 



Diet 13a should also be considered as well as the diets of Group B. Diets 8, 9, 

 and 10 of this group include fresh fish and would present the same problem 

 regarding preservation as diet 2. Diets 6 and 7 do not present these difficulties. 



ACKNOWLEDGMENTS 



In conclusion I desire to publicly express my appreciation of the assistance and 

 support received by the Department from many sources during the year 1935-36. 



Our work, which at times may be somewhat difficult and perhaps onerous, has 

 been made the more pleasant and enjoyable by reason of the continued co-operation 

 of interested persons and the various Fish and Game Protective Associations which 



