drates, 



Fat 



lb. 



lb. 



7. 



.1 



6.48 



.48 



13.48 



.58 



ILLINOIS DAIRYMEN'S ASSOCIATION. 319 



Much careful study and investigation has been devoted to 

 the question of determining the amounts of digestible protein, 

 carbohydrates, and fat needed for cows of different weights and 

 varing yields. To Professor T. L,. Haecker belongs the credit of 

 securing the data from which Table 1 has been computed. 



In all animals there is a constant breaking down of the body 

 tissue caused by wear, and there is energy expended in keeping 

 up the vital processes and in maintaining the body temperature. 

 The food used to rebuild worn-out tissues and to furnish heat 

 and energy when the animal is at rest is called the food of main- 

 tenance. If a 1000-pound cow is producing 30 pounds of 4 per 

 cent milk she will require digestible nutrients about as follows : 



Carbohy- 

 Protein, 

 lb. 



For maintenance 7 



For producing .30 lb. 4% milk 1.40 



Total nutrients required for maintenance and milk 2.10 



A cow of the same weight producing 40 pounds of 4 per 

 cent milk will require a ration conaining 2.57 pounds protein, 

 ■15.64 pounds carbohydrates and .74 of a pound fat. If her yield 

 were 50 pounds of 4 per cent milk her ration should contain 3.03 

 pounds protein, 17.80 pounds carbohydrates and .90 of a pound 

 fat. 



In feeding dairy cows, the fact that they should be fed ac- 

 cording to their milk production, is frequently overlooked. A 

 cow capable of producing 60 pounds of 4 per cent milk a day must 

 be fed a much larger amount of digestible nutrients, if she is to 

 produce her greatest yield, than a cow giving only 10 pounds of 

 milk testing 3 per cent. This point should be strongly empha- 

 sized, for a cow cannot give in her product what she does not 

 receive in her food. By referring to Table 1 the nutrients re- 

 quired for any yield of milk may be easily determined. If the 

 cow weighs more or less than 1000 pounds a proportional in- 

 crease or decrease in the food for maintenance should be made. 



From the weight of a cow and the amount of milk she will 



