1897.] PUBLIC DOCUMENT — No. 33. 115 



In judging the above results, it must not be forgotten that 

 the entire lot of cows was not fed at the same time on either 

 the wide or the narrow ration. For example, in Experiment 

 I. cows I., IV. and VI. were first fed the narrow ration; 

 while cows II., III. and V. were having at the same time the 

 wide ration. It would be exi)ected that cows I., IV. and 

 VI. would naturally show slightly higher percentages on the 

 wide ration, because it vxis fed later; and for a like reason 

 cows II., III. and V. would show higher percentages on the 

 narrow ration. In case of Cow V., on the wide ration, it 

 has already been exjdained that the first two composite 

 samples of milk show low solids, and less than 3 per cent, 

 of fat. In the third sam})le both the solids and fat very 

 noticeably increased. It is evident that this sudden change 

 was not caused by feed ; first, because the animal was in 

 excellent flesh at the beginning of the experiment ; and, 

 second, because the change was a permanent one. The cow 

 had been calved but a few weeks, and for some reason had 

 not come to her average quality of milk. It was there- 

 fore considered advisable, in the wide ration, to omit in the 

 average the first tw^o analyses. With this exception, the 

 first exj)eriment shows very little variation in the (juality of 

 the milk. In the second experiment, cows I., II. and VI. 

 were first fed the narrow ration, and cows III,, IV. and V. 

 first received the wide ration. All but Cow II. being some- 

 what advanced in the period of lactation, it is natural that at 

 least cows I. and VI. should show slightly higher percentages 

 with the wide ration, and cows III., IV. and V. with the 

 narrow ration. This natural tendency is noticed in coavs I., 

 11., IV., V. and VI. One can therefore draw more reliable 

 conclusions when the results from the six cows are averaged, 

 thus eliminating as much as possible the error caused by 

 natural shrinkage. 



