66 MAINE STATE COLLEGE 



The grain foods of the first period constituted the regular grain 

 rations which the animals had been receiving for more than two 

 years. During the entire time of these periods a record was made 

 of the yield of milk. On five days in each period the milk was 

 analyzed, as was also the skimmed milk from the cold setting 

 process. The five days' cream was churned and the resulting 

 butter was tested for the melting point, the per cent, of volatile 

 acids and the iodine equivalent or per cent, of olein. The facts 

 that are displayed in the preceding tables show : 



(1.) Yield of milk. 



(2.) Its general composition. 



(3 ) The relation of the fats to the albuminoids and to the 

 other solids. 



(4.) The melting point of the butter fats. 



(5.) The relative amount of volatile acids. 



(6.) The iodine equivalent or amount of olein. 



The results reached in this experiment are not striking, neither 

 are they easy to explain. There was a somewhat diminished yield 

 of milk in passing from the first to the second periods, while the 

 composition of the milk remained unchanged or practically so 

 throughout. Not only did the total amount of solids in the milk 

 remain about the same with the different methods of feeding, but 

 the relation in quantity of the various solids did not change, 

 greatly, and whatever changes of this kind did occur were evi- 

 dently not caused by the food. 



It was remarked by both the butter maker and by the chemist 

 who handled the butter in the laboratory, that the butter of the 

 second period was softer than that of the first. VTe would, there- 

 fore, expect to find a lower melting point during the second period 

 and this proves to be the case with the exception of one animal. 

 With part of the animals the volatile acids changed somewhat in 

 passing from one period to another, but these changes are evidently 

 entirely without reference to the character of the ration. There is 

 only one test which gives results that are significant, namely : The 

 test for olein. It appears that the iodine equivalent is uniformly 

 less during the second period than during the first and third, and 

 the differences are quite marked. It is difficult to reconcile this 

 fact with the softer appearance of the butter and the lower melting 

 point. When the olein or liquid fat diminishes in quantity we 

 would expect harder butter and a higher melting Doint. 



