222 THE SCIENTIFIC FEEDING OF ANIMALS 



of oxygen, fish should not be fed in the evening, because plants cease 

 giving off oxygen into the water on the approach of darkness. The 

 oxygen supply in water also tends to become less on the approach of 

 storms. The carp wiil instinctively refuse to feed and the food supply 

 will spoil (Knauthe). 



As a rule only "storiers" or "fries" are fed. Smaller fish are fed 

 very limited amounts or not at all. Fish intended for breeding should 

 receive natural food as far as this is possible. 



Fishponds are stocked with carp one year old, of 80 to 100 grams 

 weight. The addition of tenches, especially in mud-bottomed ponds, is 

 recommended. Tenches are more industrious scavengers than carp, 

 searching the bottom of the pond for the leavings of the latter. 



Ponds supplied with artificial food may be stocked from three to 

 four times as heavily as under natural food conditions. All fish, how- 

 ever, require natural food in addition to that supplied artificially. 



In general, fish are fed during the summer only, but daily. Weather 

 conditions being favorable about 20 per cent of the entire summer, allow- 

 ance is given during the month of June, 30 per cent during July, 35 

 per cent during August and 15 per cent during September. The food 

 should be distributed over moderate sized areas of the pond. For 

 hygienic reasons and as a precaution against poaching, the feeding areas 

 should be changed frequently. Overfeeding should be avoided; the 

 practice is wasteful and may be detrimental. 



Feedingstuffs for carp are: 



1. Vegetable. The most important of these are: 



a. Lupines, especially the yellow species. These are cracked and 

 slightly soaked before feeding, but not treated for removal of the bitter 

 principle. From 300 to 400 pounds of lupines are necessary to produce 

 100 pounds of carp meat (feed coefficient 3 — 4); 



b. Other leguminous seeds (peas, vetches, beans, lentils, etc.). 

 Their effect and value is similar to that of lupines. 



c. Indian corn, which is fed in the same manner as lupines. Its 

 high fat content leads to excessive fat deposit in the carp, which is gen- 

 erally regarded as objectionable, making them more susceptible to at- 

 tack by disease, especially in winter ponds. From 400 to 500 pounds 

 of corn are required to make 100 pounds of carp meat. 



d. Other grains (barley, wheat, oats, rye, etc.). They resemble 

 corn in effects produced, and in value. 



e. Potatoes. These are fed raw or steamed. Their food value 

 is low, from 20 to 30 cwt. being required to produce 1 cwt. of carp 

 meat. They are usually supplied only as by-feeds. 



/. Brewers' grains, malt sprouts and molasses. Usually supplied 

 as by-feeds only. 



g. Fungi. Even those that are toxic for human beings may be 

 consumed by fish without harm (Klimmer), 



