76 G Popular Editions of Station Bulletins of thf 



well distributed about the stable, was now determined at each of six 

 milkings, three cows being milked by two men, each milker using 

 the same pail. The interior of the stable was then thoroughly 

 renovated, the ceiling and walls down to within three feet of the floor 

 were covered with Avire lath with two coats of cement and the area be- 

 tween the cement and the floor was covered with zinc. After the plas- 

 tering had been finished, the stanchions, floors and mangers were 

 thoroughly cleaned, thus putting the stable in excellent sanitary 

 condition. As soon as the barn was in order, the germ content of 

 the milk from the same six cows was again ascertained on six days. 

 During this test, every effort was made to conduct all the operations 

 connected with the barn management and the examination of the 

 milk under conditions identical with those of the earlier test, except 

 for the renovation of the stable which had taken place. Soon after 

 this test was completed, the wood work and iron work of the 

 stable were painted. When the stable was again ready for use, the 

 germ content of the milk of the same cows was again determined. 

 The results from the 212 milk samples show no measurable effect 

 from the change in barn conditions. Taking as a basis the results 

 obtained in the dirty barn before plastering, the milk obtained after 

 the barn had been freshly plastered and cleaned showed an increase 

 in germ content of 114 germs per unit, while later, when the wood 

 work and stanchions had received a coat of paint, the germ con- 

 tent was 119 per unit less than when the barn was at its worst. 



In previous studies made at the Station, it was found that the 

 udders of different cows normally contained quite widely varying 

 numbers of bacteria and that the number of bacteria found in the 

 strippings, or last milking drawn from each cow, gives a very fair 

 measure of these bacteria in the udder. In these three tests, samples 

 were taken from the strippings as well as from the whole milk so that cor- 

 rection could be applied for the bacteria of the udder. If the figures 

 as obtained from the whole milk are thus corrected to account for 

 the udder content of bacteria, which could not have been directly 

 influenced by the barn conditions, the results show that the increase 

 in the germ content of the milk during milking was greater by 44 per 

 unit after plastering and less by 137 after painting. 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 greater than the difference 

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

 That is, the influence of the barn conditions was so slight that it 

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

 the other factors as closely as possible. 



A little more than a year after this renovation of the stable, samples 

 were again taken as before and their germ content carefully deter- 

 mined. The plaster, wall and ceiling of the stable were then white- 

 washed and the wood work freshly painted, after which other samples 

 were collected from cows milked under these supposedly improved 



