172 



Journal of Agricultural Research 



Vol. VI, No. 4 



Table I. — Comparison of the effect of a full and a limited allowance of water on the 

 composition of milk — Continued 



cow 2 



In studying the data obtained in these trials it will be noted that all 

 the milk constituents except the fat show very little variation during the 

 different periods, and that these differences are attributable more to the 

 individual animals than to the character of the ration. Taking the 

 average figures for the two classes of rations, it will be seen that the full 

 water allowance ration tended to increase the quantity of milk produced 

 and to cause a slight reduction of the fat content of the milk. A study 

 of the data for individual cows by separate periods, however, will show 

 that this average effect of the different rations is caused more by the 

 order in which the rations are fed than by their character. Of the data 

 obtained from the eight cows used in this test those from only one (No. 2) 

 show indication of any effect of the ration upon the composition of the 

 milk, and the data from the seven other cows are so negative that this 

 variation is probably caused more by the individual than by the ration. 

 Two of the cows, Nos. 17 and 19, show practically no variation in either 

 quantity or quality of the milk produced; one other, No. 100, decreased 

 gradually in the quantity of milk produced and increased gradually in 

 quality, regardless of the ration; while the remaining four, Nos. 8, 9, 14, 

 and 2 1 , gave milk the fat content of whifch varied considerably from nor- 

 mal in different periods, even on the same ration. These variations were 

 independent of the character of the ration — that is, the abnormal per- 

 centage of fat was in some cases found when the full allowance of water 

 was given and in other cases when the quantity was reduced. A sum- 

 ming up of all the data obtained shows that the feeding of rations whose 

 water content is varied by controlling the quantity of water drunk has 

 no influence upon the composition of the milk produced. 



