According to Buschklel. the food quotient rises to 10 when boiling the meat. It is 

 erroneous to believe that the flesh of warm-blooded animals is made more digestible 

 through boiling. One has to remember that boiling destroys all vitamins and makes the 

 protein more indigestible. 



Flesh fora^.e flour . These foodstuffs play a less importciiit role in carp and in 

 trout culture than fish flours. They are a by-product of mostly foreign meat packing 

 plants and of meat extract factories. Only healthy meat from beef, lamb and horse — 

 free from bones, sinews and fat — is used. To the lixiviated meat is added some calcivim 

 chloride, some sodium phosphate and some calcium salts. Adulterations are rare. 



Heat flour is prepared from healthy meat, meat scrap, and bones. The protein content 

 is only about 50 percent. If the flour contains more than 12 percent of calcium phosphate, 

 then according to the Food Law it must be labelled meat-bcaie flour. 



Animal flour, animal body flour, cadaver flour is similarly prepared in the iiiterior 

 rrom the bodies ofiallen animals, meat from flaying establishments, etc. The con^sition 

 is therefore similar to meat flour. It is mostly unusable for trout feeding* 



Feed lime is a by-product of glue manufacture axid contains 37 to 38 percent of 

 phosphoric acid, since it consists for the larger part of calcium phosphate. Adulter- 

 ations, among others with arsenic, suggest caution. Ffeed lime serves for addition to 

 every kind of calcium-poor food. The amount to be added is about 1 to 5 percent. Instead 

 of feed line, about 2 percent of prepared (levigated) chalk or powdered limestone (marble) 

 may be given. 



Spleen. Liver. Brain and Blood . These parts are the most valuable troui; food sub- 

 stances of slaughterhouse waste. Spleen, especially in consequence of its not too high 

 price (5^«33 per 100 pounds in 1930) has become an ideal feed for brood. Even yixen it is 

 at titles slightly expensive in some places there should be no occasion to substitute with 

 essentially poorer foods. It must be considered that spleen serves not only for the 

 production of flesh mass, but also of healthy fingerlings. Under normal conditions the 

 net food costs up to the production of a 10 gram fingerling are at most 7/10 of a cent. 

 After three months, 50 percent of sea fish nay be added to the spleen. The best fish 

 flour, 3 to 5 percent of shrimps and similar foods may be added on. The spleen is 

 especially active on account of its valuable protein and high vitamin content. A regular 

 supply of spleen has become almost indispensable for the mass growing of trout br^od. 

 Since it is difficult to obtain larger amounts of spleen for the summer only, it is 

 advisable to make agreements for the entire year and to feed spleen during the winter 

 to the fingerlings as a valuable addition food. 



Spleen is too expensive for a trout mast. The fish prefer spleen from calves and 

 beef rather than from pigs. In a large fishery, I was able to estimate that 1,210 pounds 

 of fingerlings were grown from brood Tirith about 9,900 pounds of spleen. The food quotient 

 was practically about 8. In this case, hov/ever, the losses of over 50 percent of con- 

 nective tissue occurring from preparation and sieving of the food, and the brood losses 

 of about 50 percent were not considered. The purely physiological food quotient, in 

 which food waste and the losses in food and fishes do not falsify the calculation, is 

 naturally much lower, Cornelius determined, for rainbow trout brood of less than 1 gram 

 at 13°C, a food quotient of 3.2, for fingerlings at lA'C, a food quotient of 2.9. 



Liver from beef, calves, and hogs is relatively too expensive. In several regions 



of Germany, however, on account of the low price it is said to be fed to a large extent. 

 In America liver of beef and sheep is fed to trou'^ broodlings. In comparative food 

 tests which were carried out for me in the fish hatcherj^ st Eberswalde, the brood fed 

 with liver showed a grov.-th 18 percent better than brood fed with spleen and about 10.5 

 percent better than brood given spleen plus natural nutrition. These tests were on rain- 

 bovj trout brood. In V'ohlgamuth's experiments, trout brood digested liver in 7 to 8 hours, 

 and spleen in only 6 to 7 hours. Liver is therefore a very good substitute for spleen. 



Brain is also usable, but it is less valuable than spleen. Similarly, the undoubtedly 

 vitamin- rich kidneys and hearts may be fed, but they are mostly too expensive. Blood 

 given raw is a valuable addition to iron-poor curds or to plant flours, as it contains all 



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