1922.] 



Notes on Feeding Bti-ffs for Ai'Iul 



77 



NOTES ON FEEDING STUFFS FOR 



APRIL. 



E. T. Halnan, M.A., Dip. Agric. (Cantab.), 

 Ministry of Agriculture and Fisheries. 



Vitamines in Feeding Stuffs.— Several correspondeuts have 

 wntLen wiLlnii llic last lew weeks asking for information 

 regarding certain proprietary feeding stuffs which are sold 

 expressly on the guarantee that they are peculiarly rich in vita- 

 mines. It appears evident from these inquiries that the farm- 

 ing community would welcome a few notes as to the value of 

 these " vitamines " and the extent to which they are normally 

 present in ordinary farm foods. 



" Vitamines " are substances which, although present in 

 i small amount in feeding stuffs, exercise a profound effect on 

 the health and well-being of growing and adult animals. Therr 

 composition is at present unknown, and their presence in any 

 food or liquid can at present only be detected by the effect they 

 produce on animals when included in a diet known to be free 

 Irom vitamines. 



The ori.oin of the discovery of these mysterious " accessory 

 food factors " forms an interesting story. Some years ago 

 Prof. F. Gowland Hopkins was conducting feeding experiments 

 on rats, in which the substances used consisted of chemically 

 pure protein, fat and carbohydrate, together with ash consti- 

 tuents necessary for normal growth. This constituted in our 

 then state of knowledge a complete diet, but the curious fact 

 was established that, although these rats digested their food 

 satisfactorily, not one of them grew, and if kept on this diet 

 for a sufficiently long time the rats collapsed and died. 



On esta'olishing this fact, it was decided to ascertain the 

 result of adding a few drops of raw milk in the diet, with the 

 astonishing? result that the rats grew normally. There was 

 evidently some substance present in the raw milk which was 

 c^ssentiai to normal growth, and without which growth could 

 not take place. This jrrowth-promotiug substance was called a 

 " vitamine." Contemporaneous research on the diseases of 

 scurvy and beri-beri showed that these disease conditions were 

 caused by the abseftce in the diet of some substances present in 

 small amounts in certain fresh foods. All these substances are 

 irrouped under the term " vitamines," of which three are 

 recognised, called respectively Fat Soluble A, Water Soluble B. 



