4IO 



Journal of Agricultural Research 



Vol. IV, No. s 



prevent the silage from spoiling, five cows were used in each group fed 

 silage, although there were only three animals in the other groups. 



For the second year's work grade Jersey cows, comparable with those 

 used in the first year's experiments, were purchased from the same source. 

 The 1 8 cows used were grouped and fed as follows (Table II) : 



Table II. — Grouping and rations of cows in second year's tests « 



a There was a transition period of 10 days between the two 80-day periods. 



Cow 5 in the first group, a heavy-producing cow that had a roughage 

 ration of cottonseed hulls, became so ill that it was necessary to change 

 the character of her ration at the end of 70 days in the first 80-day period. 

 With this individual the second feeding period was cut from 80 to 70 

 days, so as to make a better comparison of the data obtained from the 

 two periods. With all the other animals the data were collected for the 

 full periods of 80 days each. 



The digestible nutrients of the feeds in the first year's trials were 

 estimated from actual digestion trials. (See p. 418.) As no digestion 

 trials of the feed used during the second year's work were made, the 

 coefficients of digestion used in calculating the nutrients digested v/ere 

 taken from Henry (8, pp. 572-577), except for prickly-pear, in which 

 case our own figures were used. The energy values were calculated 

 by the Armsby (i) method. 



EXPERIMENTAL WORK 

 MILK PRODUCTION, FEEDS, AND BODY WEIGHTS 



The principal data by groups, showing in comparative form the results 

 of feeding the various rations, are given in Tables III to VI. Table III 

 deals with milk production, including the fat and solid contents of the 

 milk; Table IV shows the amount of each of the feeds consumed and the 

 body weights; Table V, the nutrients digested; and Table VI, the energy 

 values of the feed consumed. Complete data for the individual animals 

 will be found in Tables XX to XLII. 



