Hater and Inorganic Substances (UJJieral Matter)* 



<HIn^^ar^ to "fillers" and "roiighage", the nater also plays a role in the proper coa- 

 oentration of supplied food. Insufficiently moistened forage flour often leads to severe 

 inflanmation of the bowels, although the layman may reason that fish have water at their 

 disposal at all ti^es. The mere fact that the natural food of fish contains from 67 to 

 91 per cent of water indicates that iish require a great amount of moisture in their food. 



An excess of inorganic elements, kitchen salt, for instance will irritate the intesti- 

 nal tract, and so will bones, not sufficiently finely ground. 



The different constituents of foodstuffs 8ho\J.d never contain more than 3 per cent of 

 salt, and for fingerlings not more than 1 per cent since trouts are sensitive to salt. 



Cn the other hand, the inorganic materials are of great nutritive ljq>ortance for the 

 upbuilding and maintenance of the skeleton, and will also cc'vmteract hyperacidity, caused 

 l^ formation of excessive amounts of injurious acids fron oxidation of proteins. 



In this respect, recent investigations have shown that full benefits of vitamin A 

 are dependent upon the absence of hyperacidity. 



The necessary inorganic elements — as to amounts and kinds — are best assured iriiere 

 natural foodstuffs are available, as seen from the ash contents in table 3. 



Vitamins 



Although little is knom, at present, concerning the chemical nature of vitamins, 

 they are also necessary for the well being of fishes. Lack of necessary vitamins will 

 lead to disorders in the nutrition and development of fish, and since there is no limit 

 as to the growth of fish, they seem to require vitamins during all of their life time. 

 But, as always in the case of new discoveries, the importance of the vitamins has been 

 greatly over-rated and over-emphasized. 



We distinguish between the following vitamins: 



I. Growth-producing vitamin A . It is soluble in fat and present in butter, 

 codliver oil and in many plants. With the exception of com and soja beans, it is present 

 in only insufficient amounts in cereals and legumes. 



The fishbreeder should know that heat, in combination with exposure to air will 

 destroy the vitamin. 



According to Haempel (1927), vitamin A is absolutely necessary for the growth of 

 young fish. It is best to omit intense feeding of lupine, barley, etc., to carp fry and 

 one-sumner carps. 



II. Growth-producing vitamin B . It is soluble in water and is plentifully 

 present in rice, oats, com, barley, all legumes, seedlings, spleen, liver, heart, kidneys, 

 and also in fruits and vegetables. 



Lack in vitamin B will cause disorders in stomach and intestines, and will interfere 

 with growth and will genersJJLy lower resistance, 



Bspecially for trout fingerlings. vitamin B is of greatest iaportance for proper 

 growth. Galefaction, cocnbined with exposure to air will destroy these vitamins, and so will 

 prolonged storage of dried foodstuffs. Germination will increase the vitamins again in 

 Ivqpines. Through feeding with germination lupines, Haempel could reduce the food quotient 

 of it to one of 2.5 per cent. 



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