206 THE CHEMISTRY OF THE FARM 



of digestible food each day (reckoned as starch) per 

 1,000 lbs. live weight ; while a fattening ox of the 

 same weight receives 19 '4 lbs. A good cow is thus an 

 animal giving a very large return for the food con- 

 sumed — a circumstance highly conducive to profit. 



As milk is a highly nitrogenous substance, the 

 albuminoid ratio in cows' milk being 1 : 3'7, the diet 

 of a milking cow must contain a considerable supply 

 of albuminoids, and the need for albuminoids will 

 increase as the produce of milk increases. A cow 

 giving abundant milk demands a more nitrogenous diet 

 than a moderate milker ; and a cow, if a heavy milker, 

 will require more albuminoids when in full milk than 

 afterwards. A small cow will also need a greater 

 proportion of albuminoids in its food than a large 

 cow, if both are giving the same yield of milk. 

 This is because the maintenance food, which need 

 only be poor in albuminoids, forms a smaller propor- 

 tion of the diet of the little cow than of the big one. 

 When the total quantity of food is sufficient, dairying 

 statistics show that an albuminoid ratio of 1 : 7, or 

 even 1 : 8, is adequate in the case of large cows or 

 moderate milkers ; while a ratio of 1 : 6 should be 

 employed in the case of small cows or heavy milkers. 



It has been taught by many that the whole of the 

 fat in milk is formed from albuminoids. This, if true, 

 would greatly intensify the demand for albuminoids 

 in a cow's food; the theory in question is not, however, 

 borne out by feeding statistics, or by experiments, and 

 there is no doubt that in the cow, as in other animals, 

 fat is largely produced from carbohydrates. 



Science has not yet suppHed us with all the facts 

 necessary for establishing the ratio between food 



