illLK BY-PRODUCTS 109 



to the presence of various ferment bodies. Skim 

 milk that is fully soured causes less digestion trouble 

 than when partially soured. 



In the handling of skim milk the greatest care 

 should be exercised to prevent its contamination and 

 abnormal fermentation from taking place. The 

 tyrotoxicon organism may develop in skim milk and 

 cause cholera-like symptoms. The separator slime 

 should never be added to skim milk, as it contains a 

 large proportion of the dirt of the milk. Sheuerlen 

 and Bank state that most of the tubercle bacilli in 

 milk are separated in the slime of the centrifugal. 



The keeping ijualities and sanitary condition of 

 skim milk are improved by pasteurizing or sterilizing 

 it at the time the milk is separated. If the skim 

 milk is sterilized, it should be cooled and then pro- 

 tected from further inoculations. Unless it is prop- 

 erly cared for, the sterilizing may luive but little 

 effect in improving its value. Too frequently the 

 factoryman and farmer give but scant attention to 

 the care of the skim milk. A little foul sour milk is 

 left in the skim-milk tank from day to day, and this, 

 acting as a starter, immediately si)urs any fresh skim 

 milk which is added. Some diseases, as hog cholera, 

 have been spread thro\igh lack of care in handling 

 the skim milk at the creamery. 



Separator skim milk differs but little in composi- 

 tion from skim milk obtained by the gravity pro- 

 cess. From the separator skim milk the fat has 

 lieen quite thoroughly removed, while that obtained 



