THE FEEDING VALUE OF BOOTS 17 



omitted from the food of group C, while 18 Ibs. of roots were 

 added to the food of groups M and T. If one were trying to 

 find the result of this addition of 18 Ibs. of roots to the food of 

 groups M and T by comparing the amount of milk yielded by 

 these groups during the time of preparation with the yield 

 during the time of experiment, one might be led to the con- 

 clusion that the addition had had no effect whatever, or even an 

 adverse effect. The table shows that the yield of milk is 

 gradually reduced for both groups, but this is simply due to 

 the natural circumstance that the yield diminishes with the 

 increasing distance from time of calving. Probably such 

 experiences by practical farmers may have led them to the 

 conclusion asserted by several, that roots have no effect on the 

 yield of milk. To arrive at a true conclusion it is, therefore, 

 necessary, as was done in all these feeding experiments by 

 N. J. Fjord, to compare equal groups of animals fed 

 differently, but concurrently, during the same periods. Or, 

 in the present case, the effect of giving an addition of 

 roots must be deduced by comparing the yields of groups 

 M and T with that of group C during the same periods, or 

 in other words, by comparing the figures horizontally, not 

 vertically. 



We will now examine the analyses of the milk from the 

 different groups, taking the averages of the groups on all the 

 three farms. Samples of milk were taken morning and evening, 

 but as the times of milking had been purposely arranged to be 

 just twelve hours distant from each other, the quantity and 

 quality of the morning and evening milk were so nearly alike 

 that it is sufficient to deal with the analyses of the mixed 

 morning and evening milk. The average composition of the 

 milk of the three groups, C, M and T, was calculated for each 

 farm for the whole 60 days of the experiment proper, and 

 from that again the averages for all three farms. It is 

 these averages for all three farms which are given in 

 the following table. They deal with the milk of 96 cows 

 during 60 days. Each figure, therefore, represents a very 

 large number of analyses, but a study of the detailed 

 tables from which these averages have been calculated shows 

 that the same result which appears from the table below is 



o 



