Food Requirements for Milk Production 309 



THE AMOUNT AND CHARACTER OF THE RATION FOR 

 MILK PRODUCTION 



This ration is used iu various directions. It must 

 supply the raw materials for milk formation, provide 

 for the growth of the foetus, sustain the effort of 

 milk secretion and maintain the usual and necessarj- 

 functions of the animal body. The nature and extent 

 of these uses are in part quite definitely understood. 

 First of all, the kind and quantity of milk solids may 

 be estimated for any given case. The daily production 

 of thirty pounds of average milk, a performance rea- 

 sonably to be expected in a good herd, involves the 

 elaboration of 3.87 pounds of milk solids. For mere 

 maintenance it is fair to assume that the food require- 

 ments of the cow and steer would not be greatly un- 

 like, disregarding the demand for energy utilized in 

 milk secretion, and for the material used in the growth 

 of the young. On this basis the milk solids and the 

 mere maintenance of the cow call for about 11.25 

 pounds of dry matter daily, a quantity utterly insuffi- 

 cient, as experience teaches, to maintain a cow giving 

 thirty pounds of average milk. We are led to the 

 reasonable conclusion that outside the building of milk 

 solids, a large expenditure of food energy is required 

 to sustain the nerve force, metabolic cell activity and 

 warming of the extra water and food, which are neces- 

 sarily involved in milk secretion. This view is sus- 

 tained by the results of investigation. In unpublished 

 experiments by the writer with two cows in full flow 

 of milk, which made only a slight gain in body weight, 



