CATTLE FEEDING. 155 



cal compounding of rations ; deviations from them ma}' often be 

 advantageous. The same can be said of all these experimental 

 determinations, they must be intelligently followed ; they are simply 

 guides for the agriculturist, and he is to use them to his best advan- 

 tage. 



The tables of analyses appended to the end of this short article 

 will be of use, if the agriculturist will also use his common sense 

 and experience as guides. 



Rations for the production of Milk. 



Before entering upon the subject of the most rational feeding of 

 milk-giving animals, we must first know the mode of its elaboration. 

 It is not a mere secretion of the mammary gland, it is really a pro- 

 duct of the degeneration of the gland itself ; a sort of fatty degen- 

 eration actually taking place, fat cells being actively generated 

 within it. 



The milk shortly after parturition is filled with cells of a special 

 nature, and it is then called colostrum. These cells after awhile 

 disappear entirely from the liquid and we have in their place the fat 

 alobules of milk. In colostrum we have no casein but albumin. It 

 is only when the mammse are in their fullest activit}' that the albumin 

 and colostrum cells become caseii\and fat globules. The colostrum 

 cells are more or less epithelial in their nature, and have not, or at 

 most only partially, undergone fatty degeneration. The milk solids 

 of a mineral nature show that milk is not what is commonly under- 

 stood b}- a secretion, but that it partakes of the very composition of 

 the generating gland ; the salts most abundantly found in milk are 

 those of potash and the phosphate of lime, while ordinary secretions 

 are very rich in chloride of sodium or common salt. 



The average composition of cow's milk is given in Mie following 

 table : 



Fat 4.0.3 per cent. 



Casein 3.50 



Albumin 0.58 



Sugar of milk ." 4.60 " 



Mineral salt 0.73 " 



Water 8G.56 



The method of generation of milk makes it very evident that the 

 quality and quantity of it depend greatly upon the composition of 

 the gland and its development. It is well known that two cows 



to 



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