384 MARKET MILK 



where milk can be secured clean, fresh and from healthy cows 

 the mortality rate drops to about two to one, showing conclu- 

 sively that it is not cow's milk per se, but rather the condition 

 of the cow's milk which causes the trouble. 



Factors Influencing Quality.^Practically all unfavorable 

 conditions or qualities of milk can be related to one of the fol- 

 lowing causes : 



A. The Cow May he Sick. — If she is, her milk should be 

 considered as also out of condition and undesirable as human 

 food. Green com fed in excessive amounts in late summer or 

 early autumn will induce looseness on the part of the cow, which 

 condition will be promptly reflected in the child consuming the 

 milk. On the other hand, dry hay and fodder which bring 

 about a constipated condition in the cow tend to induce similar 

 condition on the part of the child. Some feeds such as com 

 silage made from mature com or roots should be fed to cows 

 in winter from which milk is sold for infant feeding, since these 

 feeds tend strongly to keep the cow in best physical condition. 



B. Strong flavored feeds, such as rye or winter wheat pasture 

 or the various wild weeds that spring up in spring or autumn 

 in various places:, also produce a milk of inferior flavor, though 

 not particularly detrimental if consumed. 



C. Air which contains foul odors of any sort may be the 

 source of disagreeable flavors in milk. Milk, therefore, should 

 be removed from the stable promptly and kept in a sweet, fresh 

 atmosphere, in the milk house. This class of trouble is, however, 

 of small consequence compared with the condition of the cow 

 and especially when compared with the detrimental effects of 

 bacteria. 



D. Bacteria are microscopic plants which grow under a 

 great variety of conditions all about us. By far the greater 

 number are of no consequence to us so far as our health is 

 concerned (Fig. 124). Milk produced in the winter time in 

 the ordinary stable may contain a dozen or two varieties of 

 bacteria, yet only two or three kinds will be found present ' 

 capable of modifying the milk itself to any appreciable degree. 

 The universally common milk organism is the bacillus which 

 produces lactic acid. 



