In the actual distribution of food, it is the rule that only so much food may be 

 given as to have been completely consumed by the fishes before the next feeding. Uore 

 or less feeding is to be done according to the temperature. At temperatures below 13°C, 

 the feeding in nursing and growing ponds should be suspended. About feeding in winter 

 ponda see Chapter X. Caution is also in order with very high temperatures in late 

 summer, for then the oxygen content can be very low. Vfhen diseases are present, feeding 

 should be suspended at once. This is especially necessary when gill rot occurs. In 

 times when strong demands are being made on the resistance of the fishes, this shoiild 

 not be further reduced by the considerable work of digestion. 



These suninarized rules are sufficient for the food distribution in the small fishery 

 operation,. With larger ponds, an exact plan must be set up to include a division of food 

 for the individual months. It must be noted that in the summer the most food is to be 

 given on account of the higher water temperatures. Besides this the heaviest feeding 

 must be shifted to late summer and autumn, because (1) in the autumn, the fishes are at 

 least twice to twenty times the size they were **ien planted, and therefore have a higher 

 food requlrementj (2) in the spring the fishes must become accustomed to take up natural 

 food, otherwise they would neglect the taking up of natural food. Therefore, they must 

 receive little or no artificial food in the spring, 



Xa a guide for the food distribution for the variously high percentual piece in- 

 crease as used for yearling and two year carps, the fomulation of Walter (1932) is 

 given in Table 22* 



Table 22, 



The Distribution of the Total Amount of Food in the Carp Pond in 

 Individual Months at Variously High Percentual Piece Increase, 



Obviously this kind of a plan can never be exactly adhered to, however, it is a 

 guide which gives protection against gross errors. All schematic and rigid summaries 

 are only to bring order in the complexity of production questions of the pond fishery. 

 These plans, however polymorphic they may be, cannot fit into the smallest details and 

 into every special case. 



The feeding should most preferably be done in the morning hours, since the work of 

 digestion increases the oxygen requirement of the fishes, and the oxygen content of ponds 

 Is as a rule higher during the day than at night. With carps the frequency of feeding 

 has but little influence upon the action of the food. According to the experiments by 

 '.Talter in 1927, the peak of success was achieved by daily feeding (except Sundays) in 

 which a food quotient of 3,0 was obtained. By feeding three times a week the quotient 

 was 3,^ with twice weekly 3.3, vdth once weekly 3,6. According to the expenditure of 

 time and labor caused by the feeding, therefore, a three times weekly feeding can be 

 more profitable than a six times weekly feeding. The question must be decided for 

 each case. A similar series of experiments by Walter in t he following year, shows how 

 very much more powerful other unbounded and non-regulatable factors are then the method 

 of food distribution, from which it nay be concluded that other factors are so strong 

 that the weekly food distribution is indifferent in comparison. 



U6 



