1 82 THE CHEMISTRY OF CATTLE FEEDING 



Kent, embracing over two thousand cows, showed that the 

 average cost of the rations used was is. 2\d. per head, and that 

 the average yield of milk was about 2\ gallons. The average 

 cost of the food was, therefore, about 7^. per gallon of milk 

 produced. Practical experts have expressed the opinion that 

 considerable economy might be effected at some of these 

 farms. 



It will be remembered that the formula used to calculate 

 the rations required by cows is based upon what may be called 

 the natural yield of the animals .under the circumstances 

 of the moment. It has been said, however, that the yield 

 can be increased to a certain extent by making still further 

 additions to the rations. This has been denied, but it is 

 probably true nevertheless. The amount of food required to 

 produce such an increase is, however, greatly in excess of that 

 calculated by the formula, and the cost of production is, there- 

 fore, much greater. 



The yield of any cow shows a constant tendency to decline 

 owing to the gradual advance in the stage of lactation, and 

 farmers and dairymen under contract to supply certain quantities 

 of milk are naturally often tempted to try to force up the yield 

 to the utmost limit of the cow's capacity. But if it be true, as 

 stated, that this can only be done at much greater expense, it 

 is clear that the process cannot be pushed very far without 

 seriously diminishing the profits. There is reason to believe 

 that it is sometimes overdone. It would be cheaper and, 

 therefore, more profitable to regulate the rations according to 

 the natural yield of milk to which the formula applies ; and if 

 this yield is not sufficient for the purpose, to bring in another 

 cow. 



Rations. The following are examples of rations actually 

 used by farmers. The average live weight of the cows was 

 about 1200 Ibs. and the maintenance ration required would, 

 therefore, be about 40 kt. 



