ECONOMIC FEEDING OF DAIRY COWS. 



67 



amount prescribed in the above standard, and the whole herd required only 

 at the rate of .048 of a pound. 



Making a summary of the results of the two periods cited we have the 

 following: 



From this we learn that in a herd where the daily average yield of milk 

 ranges from 10 to 43 pounds, and the quality of the milk from that con- 

 taining 2.45 per cent, of butterfat to 6.7 per cent, after making allowance 

 for food of maintenance, at the rate of .7 of a pound of digestible protein, 

 7 pounds of digestible carbohydrates and .1 of a pound of ether extract, 

 per 1,000 pounds of live weight, the nutrients used to a pound of milk test- 

 ing 4 per cent, fat, was .05 of a pound of protein, .22 of a pound of carbo- 

 hydrates and .017 of a pound of ether extract or fat. With this definite 

 information at hand it becomes an easy matter for the feeder to calculate 

 about how much of each kind of nutrients is required to provide for a 

 given flow of milk of fairly average quality. 



FOOD OF SUPPORT. The nutrients an animal uses in rebuilding the 

 tissues of the body as they wear out day by day, in generating heat and 

 providing energy to carry on all involuntary movements of the internal 

 organs, is termed the food of support or maintenance. The amount of 

 food an animal needs for this purpose depends upon its size, disposition 

 and environment. 



The larger the animal, other things being equal, the more food is needed 

 for maintenance, though not quite in proportion to the increase in weight. 

 That is, a small animal requires relatively more food for this purpose than 

 does a large one. An animal being constitutionally timid, irritable, or dis- 

 contented will need more than one having a docile, contented disposition. 



