RULES AND REASONS FOR FARM CARE OF MILK. 109 



be detected in the milk by the sense of smell or taste. Where the odor 

 was marked it was almost without exception greater in the warm milk 

 than in the cold. 



While it is entirely possible that warm milk may exhale odors in cool- 

 ing, it is also true that it is capable of absorbing other odors at the same 

 time and that an exposure, even for a short time, to an air that is befouled 

 or tainted with any obnoxious gases may be sufficient to impregnate the 

 milk so that the odor can be recognized hours afterwards. 



ABSORPTION OF ODORS PREVIOUS TO MILKING. 



Besides the odors that are absorbed subsequent to milking, milk in- 

 variably has a more or less pronounced odor that is derived directly from, 

 the animal herself that is usually referred to as the "cowy" or "animal 

 odor." While very little is known concerning the nature of these peculiar 

 odors, it is not at all surprising that they exist and that they 'are imparted 

 to the milk. When we understand how different volatile odors are diffused 

 by means of the circulation throughout the body tissues, it might be ex- 

 pected that a fluid having great absorptive properties as milk would be 

 saturated with these peculiar substances. Not only the milk but other 

 secretions and even gaseous emanations from the body are often charged 

 with volatile products that are consumed in the feed. While this is true 

 to a certain extent, even where the animal receives ordinary food, it is 

 materially intensified when the animal is given any food that is rich in 

 these peculiar substances. Thus the volatile principle in onions and some 

 other garden vegetables can be recognized in the expired breath and within 

 a short time. 



The peculiar property of rapid diffusion throughout the system by 

 means of the circulation and the subsequent absorption by the milk makes 

 it necessary to use considerable care in the feeding of certain food stuffs 

 to animals whose milk is to be used for direct consumption or made into 

 the usual dairy products. In the majority of cases where such foods are 

 not fed to excess and are given to the animal immediately after milking 

 the peculiar odors will be thrown off so that at the succeeding milking they 

 will not be markedly apparent. Considerable difference in different ani- 

 mals is, however, noted in this regard. There can be no doubt, however, 

 but that milk is saturated with certain odors derived from the food, if such 

 food is fed a few hours before milking. The question under discussion is 

 mainly whether such a condition will persist from one milking to 

 another. 



An abnormal condition of the animal incident to the disturbance of 

 some physiological function may also affect the milk. When cows are in 

 heat, their milk sometimes assumes an abnormal character and the marked 

 variation, chemically and physically between colostrum and normal milk justi- 

 fies its rejection for the usual domestic purposes. Animals fed largely and 

 exclusively on a single food are apt to have peculiar milk. This is not always 



