DAIRY FARMING DAIRYING. 909 



The effect of feeding roughage ami brushing cows was to increase the nnmlier of 

 colonies from 46 to 109 and 307. The greatest source of contamination in milk was 

 found to be the cow herself, and the greater jiart of this contamination was found to 

 come from the udder. Washing the udder reduced the number of colonies on an 

 average from 578 to 192. Determinations were also made of the amount of dirt fall- 

 ing from udders apparently clean, slightly soiled, and muddy during the time 

 usually rc(iuired f(ir milking and with manipulations corresponding to those used in 

 milking. AVith udders apparently clean the amount of dirt falling before washing 

 was 3.5 times as great as that falling after washing; with udders slightly soiled the 

 amount before washing was 18 times as great as that after washing; and with muddy 

 udders the amount before washing was 90 times as great as that after washing, sho\v- 

 ing the decided advantage of washing udders before milking in the iiroduction of 

 clean milk. 



City milk supply, \V. J. Fk.\ser {lUinoi.^ »S7«. Bid. 'J~\ jiji. ^51-21! 2, fiys. 9). — The 

 statements made in this bulletin are based upon the results of 7 years' experience in 

 conducting a sanitary dairy at the University of Illinois and upon the results of 

 investigations. Suggestions are made concerning the care (if yards, construction and 

 care of barns and stables, cleanliness in milking, care of milk and dairy utensils, 

 standardizing milk and cream, and other matters requiring attention in the produc- 

 tion of good milk. 



Milk productioii at the University of Illinois ( J/lii/ulx Sla. Car. 7S, pp. 16, 

 ii(js. 8). — This is a description of tlie methods employed in tlie [iroduction of sanitary 

 milk at the University of Illinois, and is distributed with the bulletin noted above 

 as an illustration of the means that maybe taken <if informing the public of the 

 metli(jds enii)l()yed in the production of good milk. 



Comparison of bacteria in strained and unstrained samples of milk, 

 II. W. Conn and W. A. Stocking, Jr. {Connecticut ,Sturr.^ ,Sta. Rpt. 1003, pp. o-J-37). — 

 This series of experiments was designed to test the effect of straining upon the bac- 

 terial content and keeping quality of milk. The milk was drawn into an ordinary 

 open pail, sampled, strained through 2 layers of sterilized cheese cloth and again 

 sampled, plate cultures being made from the samples soon after taking, after being 

 kept at a temperature of 70° F. for 50 hours, and at the time of curdling. Determi- 

 nations of acidity were made at the end of 50 hours and at the time of curdling. 



The results, which are tabulated, show on an average very little difference in the 

 bacterial content of the strained and unstrained samples, and also very little differ- 

 ence in the time of curdling. Tlie time required for curdling varied from 42 to 104 

 hours, the samples all being kept at the same temperature. This difference was 

 apparently not due to the number of bacteria originally in the milk, as the sample 

 curdling in the shortest time had at the outset the smallest number of bacteria. A 

 slightly larger percentage of acid bacteria were present in the unstrained than in the 

 strained samples, the difference, however, not being considered large enough to have 

 any significance. 



In general, samjjles showing the greatest nundjer of Itacteria at the end of 50 hours 

 showed also the highest percentage of acidity. The nundier of bacteria present at 

 tiie end of 50 hours seemed wholly independent of the number present at the outset. 

 While the lactic-acid bacteria in fresh milk ranged from 9 to 53 per cent of the total 

 number present, they constituted usually from 99 to 100 per cent at the time of curd- 

 ling. The number of bacteria at the time of curdling varied from 211,000,000 to 

 2,700,000,000 and had apparently no relation to the time of curdling. The acidity of 

 the milk at the time of curdling also varied greatly, and while usually it was from 

 0.0 to 0.8 jier cent, in 2 cases it reach('(l l.b5 and 1.23 jier cent. 



Strained and unstrained milk preserved at 70 and 50° F., II. W. Conn and 

 W. A. Stocking, Jr. {('(mnectictU Storrs Stn. Rpt. lOOS, pp. 38-51). — In continuation 

 of the above experiments tests were made to compare the number and kind of 

 2H722— No. 9—04 G 



