250 Agricultural Chemistry. 



tein and ash content as will meet the rate of development char- 

 acteristic for that species is seen in the following table: 



Days required 

 Protein Ash to double weight 



E\ve 4.9 per cent 0.84 per cent 15 



Sow 5.2 " " 0.80 " " 14 



Cow 3.5 " " 0.70 " " 47 



Mare 2.0 " " 0.40 " ." (i() 



Human 1.6 " " 0.20 " " ISO 



This is a very suggestive relation of the protein and ash content 

 of milk to the rate of growth and serves to illustrate the necessity 

 of maintaining a liberal supply of these materials in easily avail- 

 able form for the growing young. It is also necessary to remem- 

 ber that approximately 50 per cent of the ash of milk is made 

 up of the bone-forming constituents, lime and phosphoric acid. 

 This emphasizes the desirability of maintaining the supply of 

 these ash constituents in the feed of the animal as the mother's 

 milk is withdrawn and other feeds substituted. 



Supply of ash material necessary. Probably no class of farm 

 animals is exposed to as much danger in this regard as the pig. 

 Abundant supplies of lime, in particular, are contained in the 

 hays and leafy parts of plants, but these, normally, do not form 

 a part of the ration of this species of farm animals. The grains 

 are low in lime; and even wheat bran, so often accredited with 

 abundant bone forming materials, is relatively low in lime. It 

 contains an abundant supply of phosphorus, and in so far as 

 the supply of this element is concerned, normal rations for all 

 classes of farm animals, of which the grains and particularly 

 wheat bran form a part, will generally supply a sufficient quan- 

 tity. In furnishing an abundant natural supply of lime to the 

 growing animal, recourse may be had to the legume hays for 

 ruminants or the ground meal from alfalfa or clover hay for the 

 young pig. 



The meadow hays are also rich in lime, but do not contain as 



