12 AGRICULTUKAL EXPERIMENT STATION. [Jan. 



mercial feed-stufi's on account of its close relation to corn, 

 of which it constitutes a part, and its higher nitrogenous 

 character when compared with that of the corn meal and the 

 wheat bran (shorts). 



Three cows, mixed breed, from five to six years old, were 

 selected for our work. They were j^ractically in the same 

 milking period, from three to six weeks after calving, at the 

 beginning of the trial. The observation extended over a 

 period of seven months, — October 1, 1886, to April 24, 

 1887. 



The temporary changes in the diet, wherever decided 

 upon, were carried out gradually, as it is customary in all 

 carefully conducted feeding experiments. At least five days 

 are allowed in every instance to pass by, in case of a change 

 in the character of the feed, before the daily observations of 

 the results appear in our published records. The dates 

 which accompany all detailed reports of our feeding experi- 

 ments, past and present, furnish exact figures in that direc- 

 tion. This is, in particular, the case whenever such state- 

 ments are of a special interest, for an intelligent appreciation 

 of the final conclusions presented. 



As our feeding experiments with milch cows were origi- 

 nally undertaken with the intention of carrying out a sys- 

 tematic course of inquiry into the economical relations of 

 the production of milk with reference to the dairy industry, 

 as well as to a practical general farm management, it was 

 thought best, for various reasons, to begin our work with 

 cows of moderate milking qualities. The effect of difierent 

 diets on the quantity and quality of the milk produced, as 

 well as their bearing on the net cost of production, promised 

 to be of particular interest under the stated circumstances. 

 A beg-inninof of our work at the lower end of the scale of the 

 production of milk ofi'ered besides, the particular advantage 

 that the results obtained, by a careful mode of observation, 

 might find a direct application to a still quite numerous class 

 of cows on our farms, which are not infrequently assumed 

 to be of but little merit from an economical standpoint. It is 

 our intention to publish, as soon as practicable, a statement 

 concerning the annual yield of milk of some of our cows at 

 present on trial, and also the net cost of its production, as 



