578 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [112] 



of nutrititive substances. On tlie whole the food for carp will have to 

 be mixed very much on the same principles as that for cattle and other 

 domestic animals. 



Two other questions will have to be answered, viz. : (1) How much 

 food is to be given *? and (2) How is this to be calculated ? As there 

 are no data on the subject, it will be difficult to lay down exact rules 

 as to the quantity of the food. It will be correct to presume that at 

 least approximately the same principles will have to serve as a basis as 

 those prevailing in the feeding of cattle, and we shall, therefore, be en- 

 abled to fix a standard which will come as near the true one as possible. 



As a sufficient supply of food causes the growth, and consequent in- 

 crease of weight, to be very rapid both in the carp and the hog, and as 

 the carp, like the hog, is an omnivorous animal, we will take the needs 

 of the hog as a basis for determining the quantity of food required by 

 the carp. To produce the greatest possible quantity of flesh aud fat, 

 say 1,000 pounds live weight, a hog needs on an average about 4 pounds 

 of albuminous matter per day. Two pounds of hydrates of carbon 

 and fat, respectively, will correspond to this on the basis of nutritive 

 substances needed for carj)-food, as calculated above. As 100 pounds 

 of worms, beetles, and other insects, when fresh, contain 30 i)er cent 

 dry substance (comprising 13 per cent albuir.inous matter and 3,1 per 

 cent fat, the latter being for purposes of respiration equal to 8 pounds 

 of hydrates of carbon), and as the proportion of albumen to hydrates 

 of carbon in carp-food is as 2 to 1, we may lay it down as a rule tbat 

 1,000 pounds of live carp will require the following quantity of food: 

 9 pounds of dry substance, 4 i)ouuds of albumen, and 2 pounds of hy- 

 drates ot carbon, which in all probability the carp will find in a good 

 pond. This would be tlie standard quantity of carp-food, if nature did 

 not supply any food besides that which is thrown into the pond. This 

 standard may, therefore, be used only in cases where a pond is to be 

 stocked with a larger number of fish than its natural conditions of food 

 allow. 



If artificial feeding is simply to supplement the natural food, the 

 quantity of aritficial food will have to be determined by the quantity 

 of the former contained in the pond ; the proportion between dry sub- 

 stance, albumen, and hydrates of carbon should, however, remain the 

 same as that given above. On this basis a pond which according to its 

 quantity of natural food could sustain 2,000 two years' fish, weighing 

 on an average a half pound eacl^, would, if stocked with 4,000 fish, i. €., 

 with an additional 2,000, have to receive the following quantity of food 

 per day : 9 pounds of dry substance, 4 pounds of albumen, and 2 

 pounds of hydrates of carbon, since the additional weight would be 

 1,000 pounds. This quantity of food will have to be gradually in- 

 creased with the corresponding increase of weight of the fish. 



If natural food is found in the pond, the additional 2,000 fish weigh- 

 ing one-half pound each, would, in a summer, even in medium ponds, 



