2 BULLETIN 1097, TJ. S. DEPAKTMEI=rT OF AGRICULTLTee. 



by consumers, yet when all were blended into the mixed milk of the 

 herd, the resulting blend was pleasing to the taste. 

 Flavors and odors in milk result from four causes : 



1. The internal or phj-sicnl condition of tlie individual co^Y. 



2. Those absorbed witliin the body of tlie cow from highly flavored feeds. 



3. Odors absorbed into tlie milk after production. 



4. Bacterial development within the mills on standing. 



Flavors and odors of the first and second classes are more notice- 

 able just after the milk is drawn and usually do not increase with 

 time. Those of the fourth class become more apparent after some 

 time has elapsed. This bulletin considers principally the factors in 

 Groups 2 and 3, although information regarding Group 1 is brought 

 out by the investigation. 



Milk of pleasing quality is usually produced on farms making a 

 specialty of high-grade milk. On the other hand, the great bulk of 

 the country's supply is produced on farms where milk production is 

 but one of several farm activities, and, as a result, less time is avail- 

 able for controlling the factors which affect deleteriously the flavor 

 and odor of milk. With the exercise of a few precautions, however, 

 some of the defects found in market milk may at least be alleviated. 



Factors affecting the flavors and odors of milk have been investi- 

 gated extensively, and much excellent work pertaining to the subject 

 published. However, such work has largely dealt with the subject 

 in a general way. The authors of this bulletin have studied the 

 problem from a somewhat different angle. The endeavor has been 

 to suggest methods of assistance to the average dairyman in the pro- 

 duction of milk reasonably free from the feed taints too frequently 

 complained of in market milk. 



The objects of this investigation therefore may be outlined as 

 follows : 



1. To determine whether or not the feeding of the different silages does 



affect the flavors and odors of milk. 



2. If such is the case, to determine how these silages may be so fed and 



and the milk so handled as to minimize their effect on the quality 

 of the product. 



DESCRIPTION OF METHODS USED IN EXPERIMENTAL WORK. 



For the experiments, a small barn was constructed at the United 

 States Department of Agriculture Dairy Experiment Farm at Belts- 

 ville, Md. The building was of wooden construction throughout and 

 was divided into two parts, one part providing space for four cows. 

 The material used for floors, walls, and ceiling was No. 1 tongue- and- 

 groove pine. Building paper was placed on the outside walls of the 

 part used for a stable to make the building as free as possible from 

 drafts. Ventilation was provided by doors and windows. 



The stable contained approximately 250 cubic feet of air space 

 for each of four cows, or about one-half the air space required by 



