96 SCIENTIFIC FEEDING OF ANIMALS 



(0) Lime, magnesia, and phosphoric acid. — These 

 substances are found in the greatest quantities in 

 the bones. They are also used up in the body, so 

 that if the food does not contain sufficient to make 

 up for the losses in dung or urine, the animal has to 

 draw upon its own skeleton. Under some condi- 

 tions the mineral substances of the bones may be 

 drawn upon to such an extent that the latter 

 become porous and brittle. Where the soil is 

 deficient in lime and phosphoric acid and this 

 deficiency is not made good by manures, the bones 

 may become permanently brittle, for the fodder 

 plants are not able to take up a sufficient quantity 

 of mineral substances for the requirements of the 

 animal. This diseased condition of the bones is 

 particularly prevalent in dry years, because owing 

 to the lack of moisture in the soil less lime and 

 phosphoric acid enter the roots. Soft water poor in 

 lime also favours this disease, whilst insufficient or 

 acid food, digestive disturbances, etc., can hasten 

 its course. In young, growing animals these 

 diseased conditions, due to the lack of lime and 

 phosphoric acid, develop more rapidly than with 

 full-grown ones. Puppies, particularly those of the 

 larger breeds, when fed on meat free from bone and 

 potatoes or rice, show after a few weeks signs of 

 pain when they move, later even when they lie. 

 The ends of the bones and of the ribs are swollen, 

 the legs and bones of the back bend, the teeth re- 



