MANUAL OF CATTLE-FEEDING. 23 



least wlien tlie food was most abundant but was poorest in 

 salts, sliowing that nature can be very economical and get 

 on with a minimum. There is a Ihnit to this, however. 

 The exci'etion of salts can be diminished but not entirely pre- 

 vented, and if the supply of salts is too small, the animal 

 loses mineral matter continually, and sooner or later dies. 



Practical Conclusions. — In practice, in the feeding of 

 mature animals intended to be kept in a medium condition, 

 or to be fattened, a lack of the* necessary mineral matters 

 is scarcely ever to be feared. They are, indeed, generally 

 present in large excess. 



Only common salt is in certain respects an exception, as 

 will be explained more fully below. 



The opinion is indeed somewhat prevalent that a lack of 

 phosphate of lime in the fodder may be tlie immediate 

 cause of the disease, prevalent among cattle in some 

 neighborhoods, called rickets. 



This explanation is, however, at most, only valid in case 

 this lack was experienced by the animal from its earliest 

 youth up. In the case of full-grown and healthy animals, 

 the lack of phosphate of lime cannot well be the cause of 

 the disease, since experiment has shown that such animals, 

 when they are insufficiently supplied with this substance, 

 die in a comparatively short time, and before any essential 

 change takes place in the composition of the bones. 



Young and rapidly-growing animals naturally need, both 

 relatively and absolutely, a greater quantity of phosphate 

 of lime than old and full grown ones. In the feeding of 

 milk cows, too, regard must be had to the quantity of 

 phosphate of lime in the fodder. (See Part III., chapters 

 Y. and VI.) 



Uses of Common Salt.— As mentioned above, salt 

 occupies, to a certain extent, an exceptional position. 



