In a test, made at the hatcheries at Eberswalde, increase in weight and groTrth came 

 to a sudden stop by changing abruptly from a spleen diet to a diet of liver. The grorth 

 curve of tMs brood was at a standstill for 5 days, while the control fishes kept on 

 spleen showed a curve which increased steadily. 



It is a fundamental rule in trout feedjnp: that the fish must be fed until their 

 appetites are fully satiated . The faster they grow — at a certain temperature — the less 

 food goes for strict sustenance and the more goes for increase, the more favorable is the 

 food quotient, 



"Forced fattening" in trout culture is the cheapest routine, after all, provided it 

 does not interfere yrLth a good general health. Inferior food and long continued same- 

 ness of diet may be injurious to good health. Well-fed trout, just like well-fed carp, 

 are distinguished by a well rounded-out high tiack. This is. especially the case with 

 rainbow trout. Naturally nourished fingerlings are as a rule, slimmer than strongly 

 fed ones. 



The brood can be given food by two different methods whether they are nursery fed 

 in the brood house or fed in the pond. The food mash can be spread on the rough top 

 surfaces of flower pots which are then placed inverted on sticks under water in the 

 ponds or they can be hung on a wire in the brood troughs, or the food mash can be con- 

 veyed into the water by means of sieve boxes (see Fig. /^) briefly placed on the water 

 surface. There it must.be at once taken up by the brood. The sieve box is a simple 

 small box, the bottom of which is spanned by perforated metal or with wire screen 

 (see Fig. 13), In the nursery feeding with spleen of brood capable of eating, a sieve 

 with 1 millimeter mesh or perforations may be selected. The spleen which has been 

 scraped from the membranes is forcibly nibbed through the sieve if necessary. The food 

 thereby reaches the water finely divided and clouds it for a short time, vrtiich is very 

 favorable for the intake of food. 



In feeding with the help of flower pots, two sets of pots must be available, of 

 which one set must alternately be cleaned and placed on the pond dams to drj', v.'hile the 

 other set with the food is under the water. The fishes become easily accustaned to 

 this method of feeding. IThen they are hungry it has often been observed that the 

 flower pot has been emptied in a we-rj few minutes. Many fish growers maintain, that the 

 feeding out of flower pots expedites the development of strong size differences among the 

 brood. The number of flower pots in a pond must therefore not be too small. 



The first nurserj' feeding often causes several difficulties. It succeeds best if 

 the food mash (spleen) is rubbed through a fine hair sieve into the water, especially in 

 the inflow. The brood troughs in the brood house must, from this time on, be set to 

 receive as mucn light as possible. They must no longer be covered. Food rests which 

 have sunk to the bottom must be regularly removed from the brood box shortly after the 

 feeding. Brook trout as a rule are at first particularly poor feeders, but OTice accus- 

 tomed to artificial feeding, they later become remarkably lively. 



Larger trout are simply fed with the aid of a food scoop (see Fig. ^3), The trout 

 learn very quickly to take up food and come swimming to the surface with lively motions 

 when the feeder approaches (-see Fig. 43), The food is taken in almost entirely on its 

 way from the surface to the pond bottom. Entirely blind trout seek their food to a 

 large extent from the bottom. It has been recommended frequently to have a few carp or 

 tench in the pond to keep the bottom free of food residues. These fish, however, cause 

 cloudiness in the water by wallowing on the bottom and make the fishing out more diffi- 

 cult. The planting of "side line" fishes has therefore recently become unpopular. 



In any case in trout feeding the food should be very well distributed upon the 

 pond surface or in the brood box so that the weaker trout are not crowded away from 

 food by the stronger ones. It shoula be mentioned again that the brood ponds and more 

 especially the "mast ponds" in intensive feeding management must not be too small and 

 that the food utilization is good only in the correctly stocked pond. On the one hand, 

 there must be enough fishes in the pond so that a certain competition over the food 

 increases the food intake, and on the other hand, there must not be so many fishes on 

 hand that the space factor complex and perhaps also the share of natural food becomes 

 unfavorable for the individual ilsh. 



