DAIRYING. 35 



profits by giving more attention to the saving of his stable manures. 

 The nitrogen, phosphoric acid, and potash which make plants grow, 

 and which are also contained in human food, such as milk, may 

 by this method be used over and over again, and the only loss of 

 these valuable elements is in the milk, cream, butter and cheese 

 that are sold from the farm. This small loss is made up in some 

 sections by the corn, the oil meal, and other grains which may be 

 bought and fed to the cows. 



98. A summary statement of the expenses and receipts from 

 a cow per year may, therefore, be given as follows : 



Expenses. 



Cow stable, $50, per head, int., taxes, etc $ 5.00 



Value of the cow, $50, depreciation 10 per cent 5.00 



Cost of feed 35.00 



Care and labor . , 15.00 



Total expenses $65.00 



Receipts. 



Calf $ 5.00 



Value of the manure . 10.00 



Total $15.00 



The difference between the expenses and receipts is $50, which 

 must be covered by the milk produced. 



99. Assuming that the total cost of keeping a COW T per year 

 is $50, a calculation may be made to show the cost of milk per 100 

 pounds and per quart when the total production per cow varies 

 from 3,000 to 10,000 pounds per year. If a cow gives only 3,000 

 pounds of milk per year, and it costs $50 to pay her annual expenses, 

 then this milk costs $1.70 per 100 pounds, or 3.3 cents per quart. If 

 the cost of keeping a cow remains the same, $50, and the amount of 

 milk she produces per year increases, the cost of this milk per 100 

 pounds and per quart is shown in the following: 



