Torrey and Lancefield. — Rearing Salmon 151 



Amount Average 



and condition No. of Date of weight of 



of beef liver fed daily fish weighing 20 individuals Gain in weight 



1. 10 grains raw 1800 Mar. 1 .465 grams 



Apr. 2 .525 " 13 per cent. 



2. 10 " cooked . . . 1800 Mar. 1 .465 " 



Apr. 2 .590 " 27 " " 



3. 20 " raw 2000 Mar. 1 .500 " 



Apr. 2 .625 " 25 " " 



4. 20 " cooked ...2000 Mar. 1 .500 " 



Apr. 2 .875 " 7.5 " " 



5. 30 " raw 2000 Mar. 1 .535 " 



Apr. 2 .555 " 4 " " 



6. 30 " cooked ...2000 Mar. 1 .535 " 



Apr. 2 .795 " 48.6 " " 



7. 40 " raw 345 Apr. 5 1.13 " 



Apr. 19 1.35 " 



May 19 1.96 " 73.5 " " 



8. 40 " cooked ... 345 Apr. 5 1.13 " 



Apr. 19 1.48 " 



May 19 2.36 " 108.85 " " 



It will be seen that in each case the fish fed on cooked 

 liver gained weight faster than the others. Excluding 

 from consideration Nos. 5 and 6 on account of the abnor- 

 mally small gain of the fish fed on raw liver, the fish 

 fed on cooked liver gained in weight from 1.48 (Nos. 7 

 and 8) times to twice (Nos. 1 and 2) and three times 

 (Nos. 3 and 4) as much as the others in the same time. 

 Including Nos. 5 and 6 the results would be still more 

 strikingly in favor of cooked liver as food. 



To find the efficiency of the food per unit of cost, it is 

 necessary to take into account certain losses that took 

 place in the process of grinding and cooking, and in the 

 elimination of tough connective tissue unsuitable for food. 

 In ten weighings, the raw liver lost, in preparation, an 

 average of 33 per cent, of its original weight. Similarly 

 the cooked liver lost 43 per cent, of its original weight. 

 This means that for every 100 grams of raw liver avail- 

 able for food, but 85 grams are available after cooking, 

 showing a loss in weight of 15 per cent, in the cooking. 



