16 
BULLETIN 642, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE 4.—Bacteria per cubic centimeter in dual samples of fresh milk produced 
under conditions as described in Experiment No. 4. 
Udder and teats. Udder and teats. 
Date. Pauple “in Date. : able 
: ) Not 
Washed. Seat : Washed. acer 
1916. 1916. 
Keb. 28; p.mes. 2 ----- 1 1,600 SOO Mar 23 5up sete eee 37 810 2,660 
eb. 29a mies ee oe 2 3,700 SECOOE |W Mici< 24 tay. Tite are 38 1,320 4,800 
INd|oN, HAY, 10, UN Seeaeoeec 3 5, 400 3,600 |) Mar. 24, p.m...-...... 39 1,360 2,970 
Mar siaeamele se er 4 2, 200 6,500 ||. Mar. 25,a.m.......... 40 2,410 4,010 
Mar vl ipeimeeeeee scan. 5 4, €00 6,300 || Mar. 26, p. m.........- 41 1,350 4,200 
Wiles A Gls We oS oaSsonos 6 3,300 CE CRUU NY Wilkens As Bin Wis. Roe eo 42 2,740 4,750 
Mara 2 spamrcnse ere U 1,130 2,250 || Mar. 27, p.m__..-..--- 43 1,530 6,700 
IMari3. ceitnee eee nere 8 2,270 5,300 || Mar. 28, p. m.-.:...-.- 44 2,900 3, 600 
Marios) less sereee 9 1,900 3; 100) ||| Mar: 29 a. me 222222. -- 45 2,300 3, 200 
IMiaia4 Wels ae seer 10 2,700 6,600 || Mar.29, p.m.......-.. 46 2,600 5,100 
WIGHES DS Wot s sansa sse 11 980 1, 520)||) Mar-30,°a- m2 =e 47 3,900 3,500 
Marsosanmitsss es -ce- 2 3, 900 13,300 || Mar.30, p. m....--.-.- 48 1,800 3,300 
iWleye, O5 Os coscasaces 13 2,500 51005) Mans3t a. mse. 2- os. 49 4,200 6,900 
Marsal) tastes cee 14 1, 400 20,400 |} Mar. 31, p.m.....:...- 50 1,5C0 4,100 
Manel 0 Sp emsae seer i 1,370 UE AGO: iI HMjoves tl Bieta ccascdes 51 4,700 3,400 
Wiley Ih, Gio eee Sooee 16 1,150 75 od) |) BUDE, Cho We occodoseA 52 1,6C0 7,400 
Wieye WTS We sadsooeee 17 830 T0505) Ayprigs; ps We seee eee 53 2,300 4,100 
WMbhts SY Bho We Socegesn is 1,480 Za PAMY) || eX[ote 44 hos Saas ssacc 54 3, 400 4,700 
Wires NBy Tis sosooesac 19 620 UE WAY Hi eae Zh 10s Woe ocooes 55 1,400 5,500 
Mar 14am 2 eto ce 20 3,600 SFOs || As Ya20 och an lee ata 56 2520 5,300 
Mare 1a ap eile seee en 21 910 EDO Ny es Dea), Wo ltlecesssscce 57 1,900 2, 200 
Wigye. IAs Wl eooneneuc 22 1,920 2,350 || Apr.6, a.m-.--.-.: Sas 58 2,9C0 7,300 
Maieal5 ip steerer ese 23 820 PANO: Ih joes Oy Os WML esos. sa cnc 59 800 5, 200 
Whe. 1G). Bis Wel ok os cases 24 2,550 EF O0) II INfO2o Gp Bho TMS ces ccesne 60 1, 4C0 3, 300 
Mar.16, p. m..- 25 1,140 TOS) |i) ANOieS Zo 16 Walg cocde cour 61 2,700 1,500 
Wiehe. We Blaise sososcce 26 2,190 AAO), || oes Oo lle sees Seece 62 3, 4C0 9, 400 
Mar Silene eer see 27 1,970 2,680 |; Apr.9,p. m.... 63 3, 200 2,300 
Maris, asm se-s2 28 1,360 204071 Apr lOmatme se eae eee 64 2,10 3, 900 
Ile yes II) 0s 10h coo oousae 29 1,520 TE GHG) ji) Hopes NO) Ds ol scoeesescs 65 2, 400 7, 200 
Wee) 0), Gis 105 see oon se 30 820 3,070 —— 
Mars20 spn amassee a neo 31 680 2,390 Average of milk 
Wikies WL, Bh 15s cadences 32 2,190 3,410 Seymniyol CS aera ee eee 2,154 4,524 
Mat 2 eps We see-se trys 33 1,660 3, 240 Average of ud- 
IM[Ghe IE As WN so saooose 34 2,070 6, 620 der samples. --|.-.....- 739 757 
Mar a22. edn eae. nee cc 35 1,140 2,480 SS 
Mar NOS cc mitssss aaa _ 36 2, 290 3,110 Differences: yeaa |= == aaa 1,415 3, 767 
The interpretation of the average counts obtained from washed 
and unwashed udders must receive special attention. The counts 
as they stand show 2,154 bacteria per cubic centimeter from cows 
with washed udders and 4,524 bacteria from those with unwashed 
udders. It can be said that washing the udder reduced the bacterial 
counts about 50 per cent, which agrees in a general way with the 
results obtained by Stocking. This assertion should not be made, 
however, without taking into consideration the actual bacterial con- 
tent of the milk. When the number of bacteria is small a 50 per cent 
reduction indicates practically no difference in the quality of the milk, 
as, for example, a count of 2,000 per cubic centimeter compared with 
1,000. If, however, the counts were as high as 1,000,000 and 500,000, 
respectively, in the two samples, the factor causing the difference 
would still produce a 50 per cent reduction, but there would be a much 
ereater difference in the quality of the milk with the higher counts. 
The bacterial counts of the 65 samples in this experiment have 
been plotted and are shown in figure 10, which brings out in a 
striking manner the fact that milk from the washed. udders has 
1See list of references at end of bulletin. 
