ILLINOIS DAIRYMEN'S ASSOCIATION. I 2/ 



into the milk. Is it any wonder that milk that contains dirt sours and 

 spoils more readily than clean milk? There are but few things richer 

 in germ lift than the filth particles coming from the fecal discharges of 

 animals or the dust and dirt of hay, bedding, etc. 



Many think where they have strained out these particles that are 

 visible to the naked eye, that they have removed the source of trouble, 

 but let me tell you, if bacteria adhere to hairs, dirt particles, etc., and in 

 this way find their way into milk, a removal of these larger particles by 

 straining does not remove the danger. In this way you may have removed 

 the visible dirt, but what of the invisible dirt, the living germs that will 

 for the most part pass any strainer that will clean milk. These tiny forms 

 are washed through into the milk, there to grow and develop. To remove 

 them from milk after they have once come in contact with this fluid is 

 only to lessen the difficulty, it does not overcome it. They should be kept 

 out. Again some of the dirt and filth that drops into milk this way dis- 

 solves, and so if bacteria are adherant to any particles that are soluble 

 they must float off in the fluid as the solid substance passes into solution. 



The conditions with reference to the character of bacteria coming 

 from the manure are somewhat different from what they were years ago. 

 With the more intense feeding of cattle, particularly the increase of nitro- 

 genous elements, the manure is softer, more fluid, and contains more 

 bacteria. As many as 375,000,000 of these organisms per gram were 

 found in fresh manure. 



How can the germ life that finds its way into milk from this source 

 be lessened? The experiment of exposing sterile gelatine plates under 

 the animal and noting the number of colonies growing on these plates will 

 give one an approximate idea of the importance of this point. From 

 experiments on our own herd I have estimated that from 3,000 to 10,000 

 bacteria fall into an open 10 inch pail per minute. To get at this number 

 per unit of volume, one can multiply this number by the number of 

 minutes necessary to milk and then divide by the amount of milk in the 

 pail (expressed in cc.) The amount thus contributed can be quite readily 

 determined. 



Naturally these bacteria are in a dried condition and as such are 

 readily dislodged. Just as in the street where every wind current, how- 

 ever slight, whirls up from the street dust innumerable organisms, so 



