2, Animal Foods . 



Fresh Liarine Fish (54^ to 65 cents per 100 pounds in 1930), in a fUlly unspoiled 

 raw state form the most natural bulk food which the fish breeder can offer his fishes. 

 Fatty marine fishes like herring and smelt are excluded, but haddock, codfish and coal 

 fish (Gauds virons) with and without head are usable. Small fishes like gurnard (Trigla 

 hirundo), small flounders, also fish heads (for their high content of small bones) can 

 be of great value when the remaining food is poor in minerals. 



On account of easy spoilage and high freight costs, fresh marine fishes can only be 

 considered by trout fisheries near coasts (North Sea) or by fisheries having good rail- 

 road connection with North Sea Fishery Ports (Geestamonde, Wesermuende and Cuxhaven). 

 The purveyors for marine fishes are the large wholesale fish dealers of these fishery 

 ports. As a rule those fish which have become damaged and unsightly in the loading room 

 of the fishery steamer or in reloading, are sold cheaper. Fishes which have been too 

 plentifully left at the auctions, consequently reek with a strong ordor and are usually 

 taken at once to neighboring fish meal factories and can be used only (after previous 

 steaming) in very nearby fisheries. It is very Important to safeguard a most regular 

 supply throughout the year by means of definite agreement"?. Strong, ventilated boxes, 

 baskets, or food tubs are used lor transportation. Only fish in exceptional (good) 

 condition may be transported. 



In trout feeding the food quotient for marine fish is very variable, corresponding 

 to the kind of fish to be fed, the age and growing power of the trout, the height of 

 losses occurring, the kind of dispensing and preparation of the food, perhaps the height 

 of the temperature and of the oxygen content. A quotient of 5 in the dispensing of raw 

 sea fish is very good and mostly represents the highest performance in practical manage- 

 ment. Cn the average 6 to 8 must be figured. In the experiments of Riggert, as in 

 most experiments, the natural nutrition probably played a role. If there is an occasional 

 food shortage or if the fishes for other reasons grow to table size only after two years 

 or later, then the food quotient probably still lies over 8, namely at 9 or over. Brood 

 may receive, after two months, additions of faultless sea fish to the spleen; after three 

 months the addition may be as much as 50 percent. 



Dried Fish . This fish food (consisting chiefly of Chatoessus nasus) has been Import- 

 ed from East India, during the last few years. In 1930, the cost was about $4.55 per 

 100 pounds. The fish are air-dried and their price is only slightly higher than the 

 price of fish flour. Before use, the food has to be soaked in tanks when the sand, 

 clinging to the fish will fall to the bottom. According to a letter from Professor Brtlhl, 

 these fish are predominantly Ch atoessus nasus . 



Fish Flours (costing about $4.11 per 100 pounds in 1930) are made predominantly 

 from easily spoiled wares as already mentioned, fron de-fatted fish residues in the cod 

 liver oil industries, and from fish heads. The "steamed flour" is prepared by comminution, 

 drjdng with steam or flue gases, grinding and sieving. If the starting material consists 

 entirely or predominantly of herring, then the produced flour is very fatty and must be 

 labeled "Herring Flour" according to the German Food Law. Good fish flours must not have 

 been overheated. In this case the protein is altered and cannot be decomposed by pepsin 

 into peptones and albumoses, or by trypsin into arainoacids, and is therefore indigestible. 

 Heated flours should actually be dried in the absence of air, since only then are vitamins 

 preserved. Good, are most flaky, lighter "air dried codfish flours" (which are sometimes 

 also re-dried by heat action) as in the best quality coming from Norway, and all others 

 which are light colored, flaky, not too fatty (less than 3 percent fat), salt poor (under 

 3 percent, for brood under 1 percent), not too rich in bones (less than 30 percent calcium 

 phosphate), and which are not protein poor "Fish Flours", "Codfish Flours", "Lean Fish 

 Flours", "Vniite Fish Flours", "ViTiitefish Flours". According to Lehmann, among a larger 

 number of analyzed fish flours, 77.1 percent contained more than 3 percent of fat, 41.4 

 percent more than 3 percent salt, and 18 percent more than 1 percent of sand. On© contain- 

 ed up to 23.5 percent of fat and one a salt content up to 12.2 percent, lioldy, too 

 watery (containing over 12 percent v;ater) foods occur, also food adulterated with sack 

 fibers, sawdust, etc. L^ch and Claus who, in the years 1930-1931, tested the con^josition 

 of the fish flours in commerce, place the aain value on testing the flours for cleanliness 

 and freshness. The expensive chemical analysis can in some cases be omitted, since 



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