FEKTILTZER CONTROL STATION. 



349 



In order to more convenienth' make a comparison, these rations 

 are placed together in one table. The German standard ration is 

 also given. 



First k Third Periods, Cows A <fe C, 

 Second Period, Cows A & C 



Di£ference 



First & Third Periods, Cows B&D, 

 Second Period, Cows B «fc D 



DiflFerence 



German standard ration for cows of 

 same weight 



1: 6.1 

 1:12.7 



1: 5.1 



1: 8.2 



The above figures show that the total amount of digestible or 

 available material was practically the same for all cows in all the 

 periods of feeding. But while this material did not differ in quan- 

 tity it was essentiall}' different in kind in the second period from 

 what it was in the first and third. In the second period the digest- 

 ible protein was over three-fourths of a pound less daily, and the 

 digestible nitrogen-free extractive matter (starch, sugar, &c.) was 

 over a pound more daily than in the other two periods. These fig- 

 ures have significance when we place beside them the fact that the 

 average production of milk solids was 20.3 per cent less in the sec- 

 ond period than in the first, and 5.9 per cent less than in the third. 

 To what shall these differences be attributed, if not to the much 

 smaller quantities of digestible protein contained in the rations of 

 the second period ? 



It is important to notice in this connection that the cows eating 

 Timothy hay were more aff"ected by the changes in the grain ration 

 than the cows eating clover hay. It is possible, but not probable, 

 that this is a coincidence, but it can certainly be reasonably accounted 

 for by the fact that in the second period the Timothy hay ration was 

 much more deficient in digestible protein than the clover hay ration. 



