ing to the amounts of digestible protein consumed, the following 

 average results per thousand pounds live weight are obtained : 



Daily gain or loss of body protein. 



Of the trials at this Station reported in Bulletin No. 42, Experi- 

 ments II, VI and VII showed a slight gain of protein by each of 

 the three animals experimented upon, while in Experiment VIII 

 the losses of protein were very small, except for Steer No. 3. Omit- 

 ting this latter case, the daily averages for each experiment, per 

 thousand pounds live weight, were : 



Daily gain of body protein. 



In the series of experiments with the respiration calorimeter, 

 the results of part of which have been given on page 9, there were 

 two in which 0.44 pound of digestible true protein per thousand 

 pounds live weight sufficed for maintenance. In the remaining 

 experiments considerbly larger amounts were consumed, so that, 

 as pointed out on page n, the results do not show the minimum 

 needed. 



In experiments by the Laboratory for Agricultural Research 

 in Copenhagen, protein maintenance was secured with two dry cows 

 on rations containing an average of only 0.23 pound digestible 

 crude protein per thousand pounds live weight. Their experiments 

 on milking cows, however, indicated a higher figure, viz., between 

 0.45 and 0.60 pound. 



In the light of the results just enumerated the conclusion ap- 

 pears justified that a ration supplying a minimum of about 0.6 



(11) 



