EDITORIAL, 803 



ciencv of calcium in proportion to ])hosphoric acid in some of the 

 most important local feeding stiitfs, notably oat hay and corn, and to 

 this deficiency has been attributed disease, lack of thrift, and other 

 imfayorable conditions which haye been obseryed particularly \yith 

 horses and mides. It is a custom to feed these animals ver}^ largely 

 on oat hay and corn and it has been found that supplementing the 

 ration with alfalfa hay or some other feeding stuff which will make 

 good the deficiency in mineral matter will correct the evils. For a 

 similar reason the feeding of crushed bone to cattle is practiced in 

 South Africa and is attended by good results. 



The results of a number of pig-feeding experiments at American 

 and Canadian experiment stations also haye a bearing on this question. 

 It has been repeatedly shown that pigs fed corn alone do not nuUve 

 satisfactory growth and that better results are obtained when some 

 feeding stuff, for instance, animal meal, which is richer in protein 

 than the corn, is added to the ration. It was natural to suppose that 

 the improyement noted was due to the larger proportion of protein 

 and to a better balanced ration, and it is probable that the results 

 obtained are in greater or less degree due to this factor, but it seems 

 apparent that it is not the only factor inyolyed. Corn, as is well 

 known, is deficient in mineral matter as compared with a good many 

 other common feeding stuffs and there is reason to belieye that it is 

 the mineral constituents of the supplementary feed, as well as the 

 added protein, wdiich are responsible for the better gains and im- 

 j)royed physical condition. 



Of special interest in this connection are the physiological studies 

 made Ayith small animals on the effects of abnormal quantities of 

 protein or the comparative value of protein from different sources. 

 For instance, it seemed apparent from some of the observations made 

 that an exclusive meat ration was attended by serious results mani- 

 fested b}^ rough coats or abnormally developed organs. Further in- 

 vestigation, however, has shown that the abnormal conditions are not 

 dependent altogether upon the character and amount of protein fed 

 but are influenced by the ash constituents also. For instance, when 

 lime was added to the meat ration of rats fed for experimental pur- 

 poses, the coat was smooth and lacked the abnormal characteristics 

 observed with rats fed meat only. 



It is interesting to note that in the case of pigs the favorable re- 

 sults were obtained when more protein, and at the same time more 

 mineral matter, was added to the ration, while in the case of the rats 

 it was possibly too much protein which gave the unfayf)rable results, 

 but that here again the remedy was found to lie in a change of the 

 mineral matter supplied. 



