MEATS AS THOUT FOOD 



133 



than when the product is used with the jioorer meats, but the superi- 

 ority of the better combinations is not so great as might be expected. 

 In fact, our experiments with yearlings and ohler fish indicate that 

 clam heads can be fed in combination witli almost any fresh meat 

 with satisfactory results. 



During the past two years a considerable percentage of "clam 

 heads '' has been included in the ration of the brood stock at the 

 Pittsford experimental hatchery, and the results have been highly 



% MORTALITY 



15 ?0 25 



20 



AER. 



10 30 

 MAY 



19 

 JUNE 



Figure 4. — Comparative growth and total mortality of brook trout fingerlings 

 fed clam meal combined with various meat products. iV4 = beef liver, 50; 

 clam meal, 50. NU = beet liver, 25; beef heart, 25; clam meal, 25. N16 = 

 beef melts, 50; clam meal, 50. N18 = beet melts, 25; beef heart, 25; clam 

 meal, 25 



satisfactory. The fish are vigorous and healthy, the form of the body 

 closely approximating that of wild fish, and the coloration is better 

 than is usually the case in hatchery fish. The quality of the eggs 

 has also been uniformly good. The effect of the food on the eggs, 

 however, has not been checked by carefully conducted experiments, 

 but we are hoping to carry on investigations in this field in the near 

 future. 



Good results have also been obtained with a meal manufactured 

 from the dried meats of fresh-water mussels. This meal was found 

 to be somewhat inferior to the meal derived from clam heads; and 

 since there is no probability of its being available in commercial 

 quantities its use was discontinued in our later experiments. 



