the; science; of feeding animals. 31 



lowest cost per unit. This point is where the standard is fixed. 

 There are standards for growing animals, for fattening, for 

 work and for milk. 



The \\'olfi'-Lehmann standard for milch cows was 2^/4 pounds 

 digestible protein and 13^ digestible carbohydrates and fat; 

 and any combination of fodders from which a cow could disrest 

 these amounts of nutrients was deemed satisfactory. 



Feeding standards must be somew'hat elastic, for obviously a 

 cow giving four quarts of milk does not require the same feed 

 as one producing twent\- quarts. A sliding scale of standards 

 for milk has been arranged according to the amount produced. 

 Again, as the standard depends upon economical production, it 

 follows that in a locality where protein is expensive and carbo- 

 hydrates cheap the nutritive ratio will be wider than where the 

 reverse is true. 



Rations are combinations of fodders that are calculated to give 

 a profitable yield of the product for which the animals are kept. 

 These may be worked out scientifically upon a feeding standard. 

 The best practice is to depend mainly upon home grown forage, 

 and make this as complete as is profitable to do. By growing 

 clovers, and cutting early, endeavor to make the home grown 

 protein as much as possible. 



The purchase of feeds should be supplementary in their char- 

 acter. They should not usually exceed one-fourth to one-third 

 of the ration, and should be purchased with an eye to providing 

 the nutrients lacking in the home grown fodders at the lowest 

 cost. 



