78 PRINCIPLES OF FEEDING FARM ANIMALS 



extent, in the perspiration. In case of the herbivora, cal- 

 cium and phosphorus are excreted almost entirely in the 

 feces, while potassium is excreted in both the feces and 

 urine. Mineral matter in the ration is absolutely necessary 

 to the animal. Young animals fail to develop properly, or 

 even may die if given an insufficient supply of mineral 

 matter. If a mature animal is deprived of even common 

 salt, it becomes weak, languid, and finally dies. When the 



Fifi. 13. — These pigs were fed a ration deficient in phosphoric 

 (Wisconsin Experiment Station.) 



ration is deficient in mineral matter, the mineral matter of 

 the bones is used to supply the deficiency for a time. 



Ordinarily, the rations of our farm animals are not defi- 

 cient in mineral matter, with the exception of salt, which 

 usually must be added to all rations. The mineral matter 

 in most feeds is sufficient, and those feeds which are low in 

 mineral matter are fed usually in combination with other 

 feeds which make up the deficiency. An exception to this 

 statement is corn, a feed deficient in calcium, especially, 

 and in phosphorus, to a certain extent, which often is fed 

 to hogs without any supplement, or with supplementary 



