COAT OF AXIMAL. 5 



of COWS with leaky teats. Dr. R. G. Freeman has found that 

 such show a higher bacterial count in the freshly drawn milk 

 (67). The possibility of improvement in this direction is 

 apparently limited, for v. Behring reports that out of a herd 

 of 30 cows, hardly 10% approach the condition of the theoret- 

 ically perfect cow, i.e., one having no bacteria in the udder (6). 



Foremilk. The very first stream of milk from the teat has 

 been found to contain from 1,000 to 50,000 bacteria per cc. 

 (26). The average of 70 experiments by Conn (lO) gives 

 6,900 per cc. The recognition of the fact that the first streams 

 of milk drawn contain more bacteria than that drawn later 

 suggested the practice of rejecting the first stream or so, to 

 lower the general bacterial content of the milking. A separate 

 vessel is sometimes provided, to avoid the necessity of drawing 

 this foremilk upon the floor of the stall. The whole of the 

 milk contains more or less bacteria and the contamination from 

 the first milk drawn has little effect upon the general average. 

 It has been shown that the rejection of three streams from each 

 teat reduces the bacterial content of the whole milking by 4 

 per cent., an amount practically negligible (60). The rejection 

 of the foremilk is practiced much more generally than is neces- 

 sary, for there are few dairies indeed where the contamination 

 from the foremilk is a noticeable factor as compared with that 

 from other sources. This detail is a survival of the time when 

 it was universally believed that the contamination in milk as 

 drawn was derived from the orifice of the teat. 



Coat of animal. The excrement and mud adhering to the 

 hair of the cow constitute a most abundant source of contam- 

 ination. The amount of filth carried by the animal is greatly 

 influenced by the condition of the barn-xard, varying with the 

 season. Accumulations of manure to which the cows have 

 access, aggravate conditions. Poor location of barns with re- 

 spect to drainage sometimes creates conditions that cannot even 

 be alle\iated by the use of gravel and stone. Instances of the 

 pa\ing of the barn-yard with stone and with cement are known. 

 Currying and brushing the cows is effective, and should be 

 completed at least half an hour before milking is begun. Such 

 a ])eriod of time permits the bacteria-laden dust to settle to the 



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