156 



DISEASES OF CATTLE. 



Wheat bran, it will be observed, contains three tines as mnch phos- 

 phoric acid as is found in any of the other grains, and four times as 

 much as do oats, beans, peas, or rye; so that if fed in excess it will 

 readily overcharge the urine with phosphates. 



There is another point to be considered, however, in estimating this 

 danger. Wheat bran contains a far greater amount of albuminoids and 

 other nitrogen-containing constituents than do the common grains 

 (these being made up mainly of starch which contains no nitrogen), and 

 all nitrogen-bearing products contained in the blood and tissues being 

 expelled from the body mainly through the kidneys in the form of urea 

 and (in cattle) hippuric acid, it follows that the excess of urea found 

 when such food is consumed must load the urine with solids and bring 

 it constantly nearer to the point of saturation, when such solids (or the 

 least soluble of them) must be deposited. 



The following table will show the relative amounts of the nitrogen- 

 bearing products in wheat bran and some of our common grains: 



It will be observed that, with the exception of oats, none of the 

 grains contain more than two-thirds of the nitrogenous material present 

 in the wheat bran, while in the case of rye and maize there is practi- 

 cally but one-half. Even in the case of oats the albuminoids, which are 

 the more digestible principles, and, therefore, those that are the most 

 easily and speedily converted into urea, are present only to the amount 

 of two-thirds of that which exists in the wheat bran. With such an 

 excess of ash, of phosphates, and of nitrogenous (urea-forming) con- 

 stituents in wheat bran, its tendency to favor the formation of calculi 

 is fully explained. It must not, however, be inferred that wheat bran 

 is not a valuable food stuff. The inference is only that it should be 

 fed with an abundance of water, as a sloppy mash or in combination 

 with an abundance of roots, potatoes, pumpkins, or other succulent 

 aliment. 



In this connection the presence of magnesia in the food or water must 

 be named as favoring calculous formations in the urinary passages. 

 The explanation is that while the phosphate of magnesia thrown out in 

 the urine is soluble in water, the compound phosphate of ammonia and 

 magnesia is insoluble, and, accordingly, if at any time ammonia is in- 

 troduced into urine containing the phosphate of magnesia, there is in- 



