332 THE FEEDING OF ANIMALS 



The figures here given represent the actual use of nutri- 

 ents by the several animals in Eckles' experiment, and 

 not the suggested standards. These follow: 



These figures are calculated on the basis of the nutrients 

 fed minus the nutrients necessary for the maintenance of 

 the animal without production. Students of these figures 

 should bear in mind that in these investigations the only 

 measures of the efficiency of the rations have been the milk 

 production and the changes in weight of the animals. It 

 is evident that it was not possible by the methods used 

 to determine whether there was, with a given animal, a 

 gain or loss of body substance other than would be 

 indicated by a change in weight, which, as is well known, 

 is often a deceptive standard of measurement. It should 

 be said, however, that probably no practical feeding 

 experiments with dairy cows so far conducted give figures 

 more reliable as a guide to the feeding of dairy animals 

 than those above cited. It will be noted that the increase 

 in the protein and total nutrient requirement for each 

 increase of one-tenth per cent fat in milk is as follows: 



Haecker Savage 



Pounds Pounds 

 Average protein increase for .1 per cent of fat 



in milk ... .0006 .0008 



Average total nutrient increase for .1 per cent 



of fat in milk 0048 .0056 



434. Requirements of certain feeding standards for 

 dairy cows.^In order tQ apply the various standards for 



