New York Agricultural Experiment Station. 69 



In summing up the results from these 212 milk samples it is most 

 interesting to observe that they show no measurable effect from the 

 change in barn conditions. Taking the results obtained in the dirty- 

 barn before plastering as the basis of calculation the milk obtained 

 after the barn had been freshly plastered and cleaned showed an 

 increase in germ content of 114 germs per cc., while later, when the 

 woodwork and stanchions had received a coat of fresh paint, the germ 

 content was 119 per cc. less than when the barn was at its worst. 

 If these figures as obtained from the whole milk are corrected by the 

 germ content observed in connection with the udder, which could 

 not have been directly influenced by the barn conditions, the results 

 show that plastering made the germ content of the milk worse by 

 44 per cc. and that painting improved it b}^ 137 per cc. 



What these results really show is that in the last two sets of tests 

 when the barn conditions were essentially alike and unusually clean, 

 the observed difference in germ content is much wider than the 

 difference between the results when the barn was clean and was dirty. 

 The gist of the whole matter is that the influence of the barn con- 

 ditions upon the germ content of the milk was so slight that it was 

 not measurable even when care was exercised to balance all of the 

 other factors as fully as our present knowledge of germ influences will 

 permit. 



In health regulations for the production of sanitary milk there is 

 frequently included a requirement that the cow stable shall be white- 

 washed at least once a year. Accordingly, in 1911, when somewhat 

 more than a j^ear had elapsed after the plastering of the stable, 

 a test of the influence of whitewashing was made. These tests 

 were similar to the preceding ones except for the following details: 

 Four plates were prepared from each sample, two with a dilution of 

 1 to 2 and two with a dilution of 1 to 10, and the plates were incubated 

 five days at room temperature and two days at 37° C. A steamed, 

 protected pail was provided for receiving the milk from each of the 

 three cows at each milking. Samples of this milk were collected on 20 

 days preceding and on 20 days following the whitewashing, the other 

 barn conditions being kept as constant as possible. Samples for 

 the first series were collected October 1-30, the application of 

 paint to the woodwork and whitewash to the plaster was completed 

 early in December and the second-series samples were collected 

 December 18, 1911, to January 6, 1912. The samples were taken 



