52 



DEPARTMENT OF GAME AND FISHERIES 



No. 9 



*This result is in part calculated since the experiment did not run quite 74 days. 



The mortality was high as compared with that of 1930. This was partly 

 due, at least, to infection and for some unknown reason the fish fed on diets 

 5, 6, 7 and 10 appeared to be particularly susceptible to it. The percentage of 

 deaths given in the mortality column does not really show this since the time 

 is not given. When the time of death is plotted against the number an epidemic 

 period is distinctly indicated and it is in this period that the deaths, occurring 

 under the diets referred to, chiefly fall. Furthermore, the mortalities do not 

 indicate the condition the fish were in when the experiments were terminated, 

 and for these same fish it was, on the whole, quite unsatisfactory. Consequently, 

 the calculated data for these particular diets are not of much value. On this 

 account some have been omitted. 



The calculations for diet number 10 were made on the weights obtained 

 at the last weighing when the fish still appeared to be well. 



The food and gain ratio might be called the food equivalent since it represents 

 the relative weights of the different diets required to produce a unit gain in 

 weight of the fish. The costs per 100 grams gain in weight were calculated 

 on the basis of the following prices per pound: ratio F 5c., beef liver lOc, beef 

 heart 7c., beef melts 6c., clam meal 3.5., ration A 6.5c., hog melts 6c., ration 

 B lOc, ration C lie, ration D 3.25c., ration E 7.5c. With the exception of 

 the raw meats these prices do not include shipping. 



A study of the data will show that diet number 9 produced extraordinary 

 growth and that the relative cost of production was considerably lower than 

 that of the beef liver. There was no mortality and the fish were in excellent 

 condition. Diet number 2 also gave good results; the food equivalent was 

 very low as also the relative cost of production when compared with that of 

 beef liver. Diet number 8 should be recommended as well, for it showed itself 

 to be superior to beef liver alone. 



Ration F and ration C were both highly recommended. For some reason, 

 however, both proved to be disappointing. The former contains considerable 

 moisture and this accounts, in part, for its unfavourable food equivalent, but 

 the same reasoning may be applied to the beef liver, for it also contains a high 

 percentage of water. Ration C produces excellent colouration in the fingerlings, 

 approximating that found in the wild state. The clam meal combinations 

 did not prove entirely satisfactory. The writer feels, nevertheless, that this 

 food has possibilities as an ingredient of brook trout diets. 



