PRODUCTION OF MILK OF LOW BACTERIAL CONTENT. 
TABLE 16.—Number of bacteria in fresh cow manure. 
37 
Bacteria = Bacteria Bacteria = Bacteria 
Sample No. per gram. Sample No. per gram. Sample No. per gram. Sample No. per gram. 
Terenas A * UENO O00) Ili HOSS Skee Ae IPS WO; O00) I esas see see 62000007 t46nse y= 6, 800, 000 
Dares mati 1 HI OOOMOCO! |Meat 60; 000; 000 |} 82:-......2- DSOOSOOO) ||P 4ioe sees ae 9, 400, 000 
Sih en ee Se DOOROOON elt Saas see eee A (N00 COO Ill Bic s5oadee GRSOOk O00) ||P 4Senaseeen ae 71, 000, 000 
LM a ee eae 1250095 0008/10 eee ene 15,000; O00) || 342-4 - 5-22 - GHICON COON 4 Ona eee 38, 700, 000 
Gy. pee ee 40, 000, 000 || 20.........- 200007 COONS oseeee se ae 41,000, 000 || 50.......... 17, 200, 000 
Gi sein SHOOOFOOOR NW e21e 52-2 se ee TOE OOOR OOO) Osceesccone 8850005 0007|| Slee 41, 000, 000 
(Mme erste 52000 COO 22525 2 eee S 000000 RSet 14 SOON COONPo2aeeeeecee 60, 060, 000 
Bieare iin t & 23300 000M P23 asa see ae 40, 000, 000 |] 38........-. TF OOO NOOO oSeeeee ae 10, 400, 000 
Bete ari = 650;000;/000) || 24.2252 5222 OOCOSOCO SOEs ee DS OOOMCOO) llwoteee eee 8, 700, 000 
LORE A pe Ed SS COO OOO Pioccsesonace He 500s COOK 40 ease eee HOOOHOOO||Gbat 5455422 3, 200, 000 
elie eS 15, 000, 000 || 26.......... 30, 000, COO || 41......-..- 32, 000, 000 || 56......._.- 2, 900, 000 
OLS Seam. 160, 000, 000 || 27........-- 9, 500, 000 |} 42..._...--- 1183, COO OOO) sI) Giese senses 11, 500, 000 
Dowels 30 0005000) || 2825525 eee" HG S00; O00) |\\ Besse sengas 40, 000, 000 ——__—_—___. 
Te Sak eal LOE OOH000) 29.52. os Op PLOOROOOF|| ma tirane saree ss 9, 500, COO Average..| 49,645, 614 
a eeetet = Soe 690, 000,000 || 30......-..- G00} 0007 4555252 85-- 26, 300, 000 
TABLE 17.—Theoretical number of bacteria which may be added to milk by vary- 
ing quantities of manure. 
Quantity of wet 
Number of bac- 
teria added to 
Pane aded to each cubic centi- Z 
2 : meter of milk. 
Gram. 
0.5 52, 854 
4 42, 283 
13 31, 712 
49} 21,141 
eal 10, 571 
075 7,907 
-05 5, 285 
. 025 2,642 
O01 1,057 
In order to show how much manure would be added to the milk, 
on the basis shown in Table 17, Plate VI shows a number of sedi- 
ment disks.1_ It will be seen from the figure that 0.5 of a gram of 
wet manure represents a quantity far in excess of that found in milk 
as produced on an average farm, and by referring again to Table 17 
it is evident that this excessive quantity of manure would add only 
52,854 bacteria per cubic centimeter. If 0.1 of a gram of manure 
were added to a pint of milk, that quantity would add only 10,571 
bacteria to each cubic centimeter. 
Tt is realized, of course, that these figures are only relative because 
of the variation in the bacterial content of manure, and, furthermore, 
that which does enter the milk is not necessarily fresh. The figures, 
however, confirm former conclusions that manure, though an im- 
portant source of contamination in general, is not so great a factor 
as unsterilized utensils in causing high bacterial counts. 
1 The authors are indebted to George B. Taylor, of the Dairy Division, for this series 
of disks showing definite quantities of fresh manure, 
