The Milking machine as a factor in dairying


Material Information

The Milking machine as a factor in dairying a preliminary report
Series Title:
Bulletin / United States Department of Agriculture, Bureau of Animal Industry ;
Practical studies of a milking machine
Bacteriological studies of a milking machine
Physical Description:
55 p., 4 leaves of plates : ill. ; 24 cm.
Lane, Clarence Bronson, 1870-1929
Stocking, W. A ( William Alonzo ), 1872-1926
U.S. Dept. of Agriculture, Bureau of Animal Industry
Place of Publication:
Washington, D.C
Publication Date:


Subjects / Keywords:
Milking machines   ( lcsh )
federal government publication   ( marcgt )
non-fiction   ( marcgt )


General Note:
"January 29, 1907."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029613015
oclc - 22367370
System ID:

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A A!-




1W lt4 t


Property of the Unitfed Stpog Government

Issued Janiuary 211L 1907.




C. B. LANE, B. S.,
,Assistant Chief, Dairy I)irtist',,. ltreat of ,-4iintal Industry.

W. A. STOCKING, JR.. M. S. A..
Bacterio/ogist, Storrs -grictllnrat E.ipcrinmitt Salion,
Professor of Dairh iaclr'rio!o,, Con ner/hcut
.-1fricu/tnralI College.


a * : *,* a :


Clhief- A D. MELVIN.
l..t ;1a(nt Cl("tC A. M1. FARRI.'GTON.
Ch;f( irlrl: E. B. JONES.
Biorli/errn; firi.iu: MARION D[)ORET, c.hief.
Diiri Dee riod:. ED. H. WEBSTER, chief: C. B. L\KF, assistant chief.
,p.](vtkIwo D;i sii: RI ( 1ST:Dh'oIM, chief: 1'. (1. Hotrc, associate chief; MORmIS
WO.I>EN, a-istJt ll chief.
Pdetoloyi,.,I IMi;i.,lo':. Jon R.. 1MOLER, chief.
/,ra,' tilemee' ;, 1;n, icii Himi W HI(. K .IN, chiel.
Dei,';s., ril Zol,,l-y: BRANTON If. HAN-S' N, hie'f.
Eji'rie',t Staltion: E. C'. SCnROEDEn, .u perinten lent; \V. E. CoTTrox, assistant.
.I c,;ncl I ,lnsbnl I,t I I,." ( ;:' RI.F M. RiNnIa L.
Editor: .1AES M. 1H1 KENS.

7"lf. Ed. IL. Wel-ter.
A.-s.'t,,ItI .'leei: C. B. LIne. el: Win. Hart I)exier.


Butter Imstligahom.': C'. E. Gray, chemist. in charge; C. \W. Fryhofer, assistant;
E. A. McDonald, WV. S. Smarzo. WV. J. C'relicott market inspectors.
Marl..l n,/l. ,n,.,q.litie: C. B. Lane, assistant chief, in charge; R. H. Shaw,
chemist; (George M. \Whit.akr, E.llis M. Sanee, I'an C. Weld, assistants.
rl,,.-,e iecslit ,g.rn. C'. F. DInant. expert, in clharge. American varieties: John L.
Saninis, ciiiit: Jiy \V. MInore, expert maker. European varieties: Charles
Thoimc, mycologist: .Arthur WV. Dox, cleemist; T. W. Issajeff, expert maker.
.Seu/e,,er, daier,/ 111 e.xi'ileiou.: B. H. Ra'vl, expert, in 'harge; H. N. Slater, Duncan
Stuart, J.. A. Conovwr, S. E. Barris, .1. W. Ridgwayv, J. E. Dormnan, assistants.
Blel/;iie. (mnd m ier't',eeCet miie'stli11l7tines. B. D. White, expert, in charge; G. H.
Parks., architect; W. J. Latiun-r, Joeserh A. Lnckie, assistants.
Dair'i lloraturi,'s.- L. .. Rogers, bo.eteriiolgical t hemist, in charge.


Ie,,owatlefd Iettr ',ctorte's M. W. Lang, 510 Northwestern Building, Chicago, II].,
in charge.
Imteiited Iier mar/ketl: Levi Wells, Laceyville, Pa., in charge.
Ih,.le'etors: Robert McAdam, 51) Northwestern Building, Chicago, Ill.; George M.
Whitaker, Washington, D. C .: E. A. MclDonalh, Seattle, Wash.
Deputy i:,.spertor.,: S. B. Willis, Boiton, Mass.; R A. McBride, J. H. Barrett,
6 Harrison street, New York, N. Y.; H1. P. Olsen, St. Paul, Minn.


IV,.ts/'nqim, I). C., Orchuer 1.3, 1906.
SIR: I have the honor to transmit herewith a preliminary report on
"The Milking Machine as a Factor in Dairying." an investigation of
this subject by the Dairy Division having been authorized by you.
The first part deals with the practical side and the second part with
the bacteriological phase of the subject.
Recent improvements in milking machines have led to their intro-
duction and practical use in some of the larger dairies of the country,
and there are indications that these machine., may come into general
use in the near future and become an important economic factor in
the dairy industry. While the investigations so far made have been
too limited to justify any sweeping deductions or positive conclusions,
it is believed, in view of the importance and present interest of the
subject to dairymen, that the results here presented are of sufficient
value to warrant their publication, and I therefore recommend the
publication of this report as Bulletin No. 92 in the series of this
Bureau. The investigations will be continued and further results may
be reported later.
The experimental work which is the basis of this bulletin was con-
ducted in August., 1905, but owing to unavoidable delays the manu-,
script has not been ready for publication until now.
Respectfult ly, A. D. MELVIN,
Cth if' B Bu it ait.
Seclretli'y qf AgriV'lt rc.




Introduction .............................................. ............ 9
Som e m ilking, m alhine-i in u e ......................................... .. ..... .. 10
A foot-power m ilker ................................. ................ 1 it
A pow er mn ilker ................................ .. ........ ...-- 11
A milker designed f,.r either hanId ,r power ............................ 12
The machine used in the in e-tigyat ion ........... ... ................ 12
Cost of equipment fbir machine e milking ......... ........... ............. .. 13
Different kinds of Ipowter wIiic.h may Ie, utilized l........... .............. 13
Experiments in which handI and machine milking %%ere ,ollared........... 14
E xperim ent N o 1 .................................................... 1-
Time required for hand anI machines milking compared ............ 17
YieldJ oft milk from hand andI machine milking comparF-d ............ 18
Thoroness of hand and tma' hine milking compared ................. 20
E xperim ent N6. 2 .................................................... 20
Time required for hand and machine milking -ompared ..............'4
Yield of milk fr',n hand and.I machine milking oii'npared ............ 24
Thoroness 'if hand and machine iiiilki n. iipared ......... ....... 2-'5
Quality ov f the m ilk ............................................... 26
General consideration-s ..................................................... 27
Effects of milking mat-hinues ulpon tlii!- .ow ..... ...................... 27
Adjusting the machines titlih- s ....................................... . '28
Practical,-ility (if using machin-s f,,r iairge andi small herdls ............... 29
How the general intruductiori '.,f the milking ni'alhiie w.,uili i affect thte
da iry in' lustry .... ....................................... ... . 29
Suggestion s for inprotenient- ......................................... 29
Objections and diffi culties ............................... . .... ..... :,0
Need for further inve-.tiation; ....................................... 31
Results of vxperien.'e with milking machines as reported 1iy ,ar i,,,v ....... ii2
Adilendun, ............................................................ .32


Production of -anitarv miilk ............................................... .A
Experiments de-igne t, te.-.t the sanitary character of maihin--lra\i n niilk.. 34
Experiments at Farm No 1 .......................................... 14
Methoil if experiitnent ....... ............................. :1.4
First treaty enter i oi the m ilking m achine- ....................... ... :;t
-.'ond treatment of the machines........ ...................... ...7
Third treatm ent -f the- m achineA .............. ................... 411
Fourth treatm ent '.f the m a.-hines .......... ..................... 41-
Fifth treatm ent of the m machines ................................... ..... 41
Sixth treatment iof the machines ............. ... ............ 44
Keeping qualities of the m ilk ..................................... 44
Summary of experiments at Farm No. 1 .......... .............. 45



Experiments to test the sanitary character of machine-drawn milk-Cont'd. page.
Experiments at Farm No. 2 ............... ............................ 40 :
M ethod of experiment........................................... 46
First treatment of the machines ................................... 47'.
Second treatment of the machines ................................. 48
Third treatment of the machines .................................. 49
Fourth treatment of the machines ............................ ..... 50 '
Fifth treatment of the machines .................................... 52
Sixth treatment of the machines ........................ ......... 52 :
K keeping qualities i if the m ilk ....................... ............. 54
Summary of results of bacteriological investigations -...----..--------......---------- 54 i


PL\ r'- S.

PL.A'E 1. Fig. 1. A foot-power milker with attachments. Fig. 2. The saiie
machine in operation............................ ....
2. Fig. 1. A power milker iith attachments. Fig. 2. Thle caiilv
machine in operation ..................................
3. Fig. 1. Milking machine for use with either hand or ;'o%%er. Fig.'2.
Same machine in operati'on............................
4. Fig. 1. Milking machine used in experiments. Fig. 2'. The -arne
machine in operation ..................................






rTEXr FII;l HE.-.

Bacteria in atmosphere of barn at farming No. 1.......................
Bacteria in matlhine-drawn milk in experiment N0. .37 ...............
Bacteria in machine-drawn milk in experiment No. 101 .............
Bacteria in milk drawn by steamn-terilized machine in experiment
N o. 101A ........................ ....... ......... ........... ....
Bacteria in machine-drawn mIilk in experiment No. 103 ..............
Bacteria in atmosphere of barn at farm No. 2 ........................

Fm;. 1.


DigIhized b,' ie Irnileinel Aichiae
i1l 2012 wilh luindorig Irom
Uni,.-r.ily ol FIo,ida George A Smalners LiDiaries. *111 suppuOL irom LY'RAS.IS aria Ihe Sloan FouLndabon

hip rchie oig details machinOOuni



By C t I..AN, B S.,,4h11 hiiill ) I|,J i 1 ', ,.if A ,mm /Inl f ,hi t i.


For more than a quarter of ai contllr:v machinery has been tucces-
fully used in separating the cram: from the milk and churning it into
butter, but a machine for milking the cows ha.-, be..n more difficult to
supply. It has long been rcaliz"d that a; smcces-ful andi practic;il cowv
milker would mean a protitalble revolution of the dairy industry, a-; it.
would render the work of milking muitch easier and reduce thile nccity
for hired helpl), thus making the dairiymain more independent. Efforts
have been made )y score, of invent(ors for more than half a century
to con-struct a machine that would milk tcows in a satisfactory manner
and without injury. The (German writer Martiny states th:.l h2t1 dif-
ferent milking machines known to him had been patented in different
countries or mentioned in the dairy literature between the Years 1S77
and 1S98.
The annual report, of thle IUnited States Conmmi.-ioner of Patents
show that during the period of 34 years frin 1S72 to Il.J)5, incli-,ive,
127 patents were taken out in this country alone for milking' machines
or separate parts of them. A number of machines have I,,en slcces-
ful in extracting thie milk from the cow by either pres-,ure or suction,
or by the two combined, hut have fallen -hort of being practical in
some vital point. Naturally v, inventors have attempted to imitate the
way in which the calf sucks its dam. The difficulty has been to
reproduce thie peculiar influence which the sucking calf has upon the
cow and to devikse a machine which will not irritate the animal and
which will do its work without injury. Another difficulty in devising"
a cow milker has been to construct it so that it could lie adjusted to all
cows. Individual animals vary greatly in the size and conformation
of their udders, and even the same cow varie, somewhat. in the size
and shape of her udder and teats during tile different .s.tages of her
11522-No. 92-07-2 9


lactation period. Cows also vary greatly in disposition and temper-
ament. A successful cow milker, therefore, must meet all these
different conditions. Since milking must necessarily he an artificial
process. it hai' been thought for some time that animals would become
accu.-tomed to being milked by machinery just the same as they.
become accustomed to hand milking, provided a milking machine
could be perfected that would be comfortable to the animal when in
operation. A heifer, for example, coming into milk the first time
would take us readily to one artificial method as to another, other
things being equal.
While no milking machine yet invented has shown its practical
value in a way' that has led to its general use, recent improvements in
machines of this type have resulted ingreatersimiplicity of construction
and effectiveness in operation, and consequently they are in practical
use in a limited number of the larger dairies. Indeed, the prospect for
the general introduction of milking machines appears to be so favor-
able that it was thought advisable by the Secretary of Agriculture to
authorize an investigation of the fundamental problems involved in
the use of such machines. These fundamental problems may be stated
as follows: (1) The practicability of substituting machine for hand
milking in the actual operations of dairying; (2) the effects of machine
milking on the quantity and composition of the milk yielded by the
cows: (3).the effects of machine milking on the cleanliness, sanitary
character, and keeping qualities of the milk.
In making such an investigation it was, of course, necessary to
select sume machine for use. The machine selected is one which
wa, found to he in actual use in a number of dairies, and one which
appeared to offer adequate means for conducting the proposed inves-
tigation. Its selection was not intended as in any sense a recom-
mendation of thi, particular minachine to the favor of dairymen. It is
believed, however, that. in so far as the investigation has demonstrated
the merits of this machine, it will benefit all inventors and manufac-
turer, of successful milking maichine.-.
The authors fully appreciate the fact that these investigations have
been too limited to justify any .weeping deductions or positive con-
clusions. But in view of the probable general introduction of such
machinery in the near future, it is believed the results of the investi-
gations are of sufficient value to justify their publication.
As a complete account is hereinafter given of the machine used in
the investigation, a brief description will suffice for the other machines
presented here, none of which were used in this investigation, and in
regard to the efficiency of which no opinion can consequently be



This, machine (pl. 1) is designed for use in small herds and has no sta-
tionary fixtures,. It consists of ai sutction pure1) worked by foot power,
2 pieces of rubber hose. and s suction cups to be attached to thile teats
of the 2 cows, which can be milke-d at thle same time. The milk passes
thru the cylinder, and also thru the valve in the pump p)istonl itself.
The operator sits between thlie 2 cows and works the puLmp with his
feet. On opening the spigot the suction rapidly draws the cups over
the teats and the milk begins to flow into the milk pail, which is hung
on the spout of the pump.
The teat cups are hollow and conical. Nearl y an inch from the
large end thile cup is almost closed by a soft rubber diaphragm: this
disk, being elastic, fits air-tight around the different-sized teats. The
teats fill the conical cup except at the small end where suction is
applied. The cup is made of three pieces of smooth hard rubber. To
the end of the cup is attached a piece of glass tubing thru which the
milk may be seen, and this is again connected with a small rubber
tube. By means of a spigot in the tube the suction may ie cut off
when the teat i., empty. The milk is conveyed from the spigot to the
head where the milk from all four teats unites and passes into the large
hose which carries it to the pail.
This machine has, been in operation since 1-s92.


The accompanying illustration (pl. 2) s-hows a cow milker which
has recently been l)ut upon the market. It consists of an ordinary
milk pail made of block tin and holding about 1. quart.,. On top of
this pail is a tight-fitting lid of aluminum. On this lid is mounted a
pump or pulsator which works automatically and causes, the intermit-
tent action of the machine. Connections are made means of rubber
tul)ing to the exhaus.,t and air-pressure pipes, which are laid thru the
stable with convenient liranche.- between the cows. Two rubber tubes,
each about 3 feet long, are also connected with convenient nozzles on
the lid, and on the other end of each are 4 cups which fit snugly over
the cow's teats, 2 cows being milked into one pail. As the pullsator
oscillates (at the rate of about 60 times a minute) the vacuum is alter-
nately turned on and off, the teat cups causing suction and release at
each alternate stroke.
The machinery for operating the pulsator consists of an exhaust
pump and a compressor; the exhaust produces the stuction and oper-
ates the pulsator in one direction, while the compressor operates tlhe
pulsator in the opposite direction.

*[ *.* :
The milking machine .,hown in Plate 3 consists of simple air
composed of two cylinders, each of which is independent of the.i
in its action. One cylinder milk., one cow, and one the other.
valve chambers, supported at thle ends of the rods, are for the purple
of keeping the milk from running back into the pump, and also to giw
the pump sufficient and continued .suction for the space of about to,
to fifteen seconds. When the pressure is off of one of these valve'.:
chambers the milk flows from it of its own gravity into the pailA.
Each cow can be milked separately, or both can be milked into oneG
pail, as desired. Cows cin lie milked into either open or closed pailhs
The machine is operated by either hand or power, the hand machli|"0
being convertible into a power machine by simply bolting an air devio :,
to it. In the operation of the power machine it is necessary to pipig!]
the stables, a comprest air tank being required, which must be filled"'.:"
by some power running an air compressor. There are no pulsator.:;:!!
or vacuum pumps in the construction of the machine. The teat cups
are provided with a rubber sleeve. ...A
'.. ,.s;3
With this machine the milk is drawn by intermittent suctiao.r
The suction may be created by either a vacuum pump or a steaf
ejector. Connected with the vacuum pump is a vacuum reservoir andx
a pipe running the whole length of the cow stable, with a connect
valve or vacuum cock between each pair of cows. A safety valve"ia|.
connected to the reservoir to prevent the vacuum from running highS1..
than is desired.
The machine itself (pl. 4, fig. 1) consists cf a heavy tin pail, whli&o
is cone-shaped and holds about. 55 pounds of milk. The cover of t
pail is a disk, in which is a vacuum motor which produces the pal
tions in drawing the milk from the teats. The cover fits the
tightly and excludes all air. B
To operate the machine it is placed between the pair of cows to
milked. A rubber tube connects the pail top or pulsator with" t-i
vacuum cock above the stanchions. On opening the cock the air .....
drawn from the pail and the motor immediately starts. The dego$
of pressure maintained is about one-half atmosphere, or 7J pounds t'w
the square inch. Leading from the pail .cover or pulsator are t %
flexible tubes besides the one leading to the vacuum cock above
stanchions. At the end of each tube are 4 cups, which are fitted o
the teats of the cow. The milk from the 2 cows is discharged iiaY.
one pail (pl. 4, fig. 2). In operation the machine makes a low, click-Vi
ing sound, which is caused by the motor. The vacuum pulsations rnitil.:.
from 50 to 70 per minute and may be easily adjusted to the" speed \


BUL. No. 92, B. A. I.




BUL. No. 92, B. A. 1.




BUL. No. 92, B A I.




BUL. No. 92, B. A. PLATE 4.


MENi" ,
r :.,



Bu-. No. 92, B. A. I


a decrease in yield, but. the milk would be of poorer quality. A sim-
ilar effect is produced in the case of machine milking. If the engine,
or whatever power is employed to work the pumps, stops for any
cause during the milking, a marked decrease in the yield of milk
G,.,'1;ne e;nqbic..-These are most commonly eniployed for power
at the present time.
lF/,lcr;/ii mo/or.%.-Some farmers located near cities find electricity
the most convenient power. This has worked successfully on two
farms at least. In one case a trolley line passes near the barn and a
wire i- attached to the main trolley wire and connected with a 1-horse-
power electric motor inside of the building. As electric roads are
now being rapidly built thru country districts it is quite possible that,
thi, mna y prove a popular method of securing power to operate cow
s,/,1,, poiri,..-Steamn engines are employed on some farms, and
they will be found to work satisfactorily in supplying power to
operate' the milking machines. Where steam is used on farms for
other purposes it can be made to run the milkers with but little extra


Two experiments were conducted by the Dairy Division in which
tests were made to determine the time required to milk by hand and
by machine. The yield of milk, its chemical composition, and other
points that were considered of interest to dairymen, were also studied.


Front a herd of 13 cows, S were selected for this test, the others
being nearly dry. The animals were Jerseys and Ilolsteins, all 5
years old or over. This herd had been milked with the machines for
over three years.
The cows were divided into two lots of 4 each in such a way that
each lot gave practically the same amount of milk. The test con-
tinued for thirty days and was divided into three periods of ten days
each. At the beginning of the first period. Lot I was milked by hand
and Lot II by machine. At the end of each period of ten days the
methods of milking the two lots of cows were reversed so that the
result, from milking by the two methods could be compared. The
milking was all performed by one man.


TABLE 1.-Machine milkig: Time required to mnillk, and yield ofin milk and sirippings.

The cows and dale.

LAT 11, 4 COWS.
July 21............
July 22 ............
July 23.............
July 24 ............
July 25 .............
July 26.... ........
July 27 ............
July 28 .............
July 29 .............
July 30 .............

Daily average......
1.OT I. 4 rows.
July 31.............
August 1 ...........
August 2 ...........
August 3..........
August 4........... i
Augu,,t s ..........
August 6 ..........
August 7...........
A ugu.t 8........
August 9........
Tota.l ....
Daily average.
LOT 1i. 4 cows.
August 10 .........
Auguqi 11 ..........
August 12..........
August 13..........
August 14 ..........
August 15 ..........
August I( ..........
August 17 ..........
August IS ..........
August 19 ..........
Daily average......
Grand intal ..
General average...

Morning. Evening. Total Ii

Yield of milk. d Yield of milk. Viel
tip___ Cd __ 2
El .-- S------- ---
"5 I I i,., 3 a. .',.
'- ". '- 3. o c '

| ,. I - . . .
2) [ C, -? ; i f C'

iin. Lbs. Lbs. i Lbs. Min. Lbs. Lb6. Lb.. .1m.n. Lbs.
14.00 30.50 1.25 31.75 13.00 2.5.00 1.60 26.50- 27.010 ..50
14.00 36 50 .75 37.25 12.00 34.7.5 .80 35. 5! -.,, 00 71.25
14.00 31.N50 .,50 32.00 13.u00 28.00 o8.1 36.10 27.0U0 b9.50
13.IS 36.5, .7f, 37. 2.5 15. u 36. 5 .10 37.00' 26.50 73.00
14.511 35.00 .b0 3.1.5j u1 .t50 33. u) i 3) 50. 26 00 O 0.01l
13. Ut0 36.511 .50' 37. 0 12.5i 34.5-0 .5' 35. fi0 25.50 71.00
12.50 34.00 .2: 34.25 12. u 11 32. 10 r.0 32 6u0 2 50 5 0U
13.001 30.50) h5.2-j 35.75 14.uO 34 ',J .40 35. 20! 27. U00 5.30
13. U0 35. 00u .775 35.75 13 50' 32'. 10 .40 32.401 26i. 50 70. (0
12 ,.u 37. 0S .601 39. 0, 12 t0J 2Ju. 2.5 .90 30.151 24.0011 66.573
133. N') 34C.. Soi 11.iui 357.5W 126.50 i321.Ro 14.200.0'0326. 00262. 668. 30
13.39' 34 65i 11U 3.'> 7"'. 12..I 5 32. I 1.42 33.60, 26. '0 66. %3

13 001 30 00 .75' 12 51 27.30 1.80 29.101 I'12.50 57.30
.3 50 34.50 .75 3).2"5, 14. 'O 27.30 .ou 27. 0 27 50 61..S
13.0,1 34.00 0 34.5oi 13.00 27.0u i .50 27.50, 21) 00 t.I.OU
12. 50 3 50 36 .00W 13.00 21. o0i l. Ou 2-. 00 2).50 60. Ou
12. 00 3.0 76 32 75 13 00 24 50 .;5 25. 25 2,.00 5'6. bu
13.00 34.50 .7., 3- 2 15.0 26.25 1.00 27 25 2'1.00 io 75
12. 5, 32.50 .75 33.25 9' 14.00 25 .50' .t30 .5 .0 W-. 50 16. 00
13.00! 33.00 .50' 33.5 i 14.00 2' .'75 2 00 27 u0 C1u. 25
12 33.50 .50 34.00 1.50 27.75: .7' 2s. -0 2S.001.1 ..2.5
13.00, 31.2.5 .0 3.75 13.00 34 004: .0 34...4LI 2.. 0 68.
-- --i -. .
128.00 334.2,o 6.25 340 50137. 00 271 8 7..7o27$. 6026%.0.i 600.1i
12.SO0 33. 42 .62 34.051 13.7,1 2; 081 .77 26.50 60 51

11.00(10 36.00 .50 36.50 11.25 30.10 1.00 31.101 2225 66.10
12.00 36. (N) .2.5 36.25 12 01' 32 00 .2:; 32 252' 2'4 00 68. Ui
13.50 33.00 .0z 33.50 15.00 .27 7-1 5.251 33.00 2N 56' 60.i7.
12.50 34.00 .2) 34.'25 13 u,'31.o0' 3.7,5 31.75, 2.611b 65.00
13.00 40.00 .21 40 '5 I1.0U 26.oU 1.50' 27 .50 2 Oil I 11.00
11.00 39.50 .2. 39. 7' 16.50 33.50 .25 33. 7 311 -d- 73.00
13.00 35.50 .50 6.0U 13..5u 31 00 .70 31.70 2t;..0 66.50
12. 60 34 60 25 34 75 14.u, 36 50 .295 36.7." 26 5i 71.00
13.00 33.00 .25 33 2'5 14. 50 4u. 00 50' 40. 60 2. 00 73.00
14.001 40.00 .,<0 40.50 1,. ou37.50: 5.75134,125 30.000 77.50
129.00 s61.503 .30 3L,5.00,141.7'32.351 19.20344 55)270.79 686.-,
12 90 36.15' .3 16.5to 14 171 32.53J 1.92; 34.45 27.07 tC fi6.
,390.S 142.2 20. 751.063 00.407 "591S u 41.1 95. 15797 7511.960..i
13.02 31.71 .69. 35.43 13 57 30. 0' 1 37 31.97 26 9 65.34

or day.

d of milk.

2 V

i E-
if I.-

Lb( Lbs.
2.75 5. 25
1. 55 72.80
S8.t0 u.. 10
I T 74.25
l.UO 71.00
1.d 7'2.00
S.4" 6.85
5 fi5 70.95
1. ]'. 71.15
1 1 .15

-* ,150
2.52 69.35

2 5.5 59.85
1 2-5 63 06
1. i 62 00
1.5 '61.51
5.50 55. 00
1. 7' 62 50
1.W: fig9 0i
1. 25 C.l SiW
1. 2 62 .!0
.9L 69 15
141.0 61. u10
1.40 61.91

1. 5u 6: 6')
.50 6_ 50
5.75 66 50
4.00 69 00
1.75 0,.'a,
.501 73 50
1.20 67.70
W.,C 71 50
.7S 73 7.
6.25 l 3 75

2-. 70, 709 50
S227 70 95
Wl 402,U22 10
2.0 b 67.40

a One ciwl h-ld up milk (7.5i poundsI on Pm tounI of stranger being in barn.
bone row held sip milk 15 puundsi on dLcunl of stranger being in barn.
c Black row hr-lId Lip milk ,ndi gave 4.75 pt undrs by hand.
dBlack crw hlid up milk and gag'e I poundiis by hand sliranger in bar).
e Black cow held up milk and gave 6 pounds by hand.


TI URLE 2.- [fvini ,nll.,. ;/ T 1,in, .,IJ r fit., w II u,,l i.iel' uf min ilk and stripping.

Mrniiiiu I: ciminL" Toial for day.

|. i.d .f Diilk. : Yie ld if milk. Yield of milk.
Ti^; .-,w n.l' = -^- ^- < _.. -^ -= --
Th "nw and= =

I ~ i^ ; *. i L c. 6-
__ S

l I In 1IV Ll. Lb...
.M/-, P ... J., L ., i.i | ..I, M,, | .b. .1,,,. / ... Lbq. L .
lr' 1 ....... _'.1 i I 'lli .5''1 3-2 .50 2iJ Lj il 3' 2LI I '0 :4 1 IU 41.000 63 .'0 3.300 6 .6500
.illY ; ....... ... 2' .1. "i. i' 1 .5 l7 1' 0 D 21 '120 Oil 320 '2 3 O I.I 0i 2.5(j0 67.700
.iii . '2 .-1 Slli -4 Io I 0 3. 0 17 I.I 2- l 1 0 90 32.t..,O 62 20 2.700 64.900
IA. "I .. ; I lU .._ "ii I 2 2.. I:t.. 1i; in 3.LifI 1.'"S .31 25 37.0O nfi 00' 2 500 67.500
Ii,! *..........24 .1 i' 1 -:. 36.25- 20. "i1 29 75 1 31 110 1.5 111 64.7 "2 500 67.2.50 -
i .. ..... 1' '111 13 S 45 oI 1 : 16. bu1 17 Iiii :;i 51) 1 u .3' 00( 36; .00 70. Ou 2. .500 72.500
I3 .5 ... -' .: .' il 2 t. 21. 9 IV 12' 0(1 fil) 33 D 3; .r)O 64.00 2_950 66.250
liii' -"'......... .....i .,:' lI-Il I.1 3.;O 17 26 3, 00 .00 .10 l Oil 41.0U 68.00 2.000 70.000
il' 'i ... ... i.2'' "i6. Lu) I .') 36. '%L. 1I'.l 3.1 80 1 I1 34 90 3" 50T 68 SU 2.600 71. 400
I t ...... 2 1I" :i '.1 1 7 .; 31.25 1 1 :.t i i 00 l.L.i :1 f 90 37 O O 1 62. 30 3.650 66.150
". ..I. -'2' i.;.- ii I 1'0 351 Il 177 t'.',:l. t5 13 50329 1, 3.q :4 2 6.: 6l,, 26 500 1i80.150
i.lld ,1 .t!' :. .12 1 : I' ] ki 3, III 7 ;72 31 ",6 1.3.5 32 91" 39 2.:l 65.316, 2. 6,M0 68.015
nI'T i l *I i'i'
Jil: '1 ....... ". li : f ill 1' 37.; ,' 21.00' 3.1 .i 1.0i" 321..50 47 000 70.30. 1.750 72.250
Aui.i-l 2', '." .,1 ,liI 7, 31.7.5' -20.0u .31 60 .61.l 321. (I1 4. 00 62 60 1.'250 63.850
AiL, t i[ 2 ...... 21 .111 I il .I 7% 31 7.5 19.0(I. 3i 00 .( i 33. 7.5 10. 0 i 67.00, I 0O 68.500
Aii-3 3 .f 2i If 2. 0 '' ;.'0 3 .50 21 Of0 31 5' 90 32. 10 14.000 57. 50; aS. 400 65.900
AII I-|t I .... . -'3 .%1 ::1 (i 6 -7-, 31 7.5; -1000 33 7.I 1 3-, 06 13.W0 64.7.7| 2.050 66800
Aici- I ;4 21 IIC 7- 4: .31 0
Ail .. "1 rI i; 1il1 7.5 36 7, 1 22. n.i o. n 00, 1 -' :1 3 .-> 43 ti ll 8 00 2 000 7U.000
Ai il-t i ... 24 on .I :i 0 3 2-'.UO, 19.111. :1I 00: .'01 31. 50 43.0 1 62. :01I 1.000 63.500
I 2iii*[ 7 .... .. 2" i"S 5 o .10 :, -Sli 23.0Mi 30 701 I 00' 31 70 4.5 000 '5. 70' 1.500 67.200
.AI], '. 3 .... I. '3 "1i .;'. O0 .,0 3 Ol O 21 50 NI. 'D1 7N. 1 '1 4" 4 .64" 70 70 1.2.50 71.950
AllguL .' ...... 21 O),i ;ir 1O I 41 .'6 ni1 19.00 Q 43 0 5,1' 3: '.0 43 000 69. 10 I 000 70.400
Ii-'I . ai ,*l I 111 1 1 '17 20i.. 041:1'24. 6" A 43 10 I 439 .500 6 8. t.'" 21.700 6, 0.350
.iIl' '- ".. .. 2 3 i .J1 411 1 '2 31.72 2f' 6'O .i 46, A1I A3 ._1 43 ill 6.S .S61I 2. 1701 68.035
11, I I, .411 ,

.\ae,-tl I0 ...... -;1 2 (i O I 00' 29.00, lii.. (i -1' 75 2 Nl. 27.75 37 000 .3. 7. 3. 000 56.750
.A iII-' 1 I- I ...... -14 V'l 31 lu 7' 31.7;.5: 1.' "J 241. 00 .',11 21 0Li 43 00U 55.00 1.550 b6.5.50
I fig -l 12 ..... 21 0i -', 1 i, 0 29.00i 21n oif 2, 2". 1. 10' 2n 3.5 41 000 53.75' 1.600 i5 350
A I1.'141 I; . I 1. :I Ii Ij I 31.S ,i It6 '01 2. 50 1.5 2 9 7 :37.000 .", .O 2 .500 61.000
I -l. 14 fill 3 111-, 2. .13. 2.), 1 1l "- *6 2 ti'l 27 2-5 40 1100 59 25 1.2.5l" 60.500
\ 1.i-t I 1 .... I "i t 32 N,| l 11 '. 2"i or 1 2' 3 ** 3'0 ) 39 oiiJ 61.00 1.7.50 62.750
'1 .'nn-L . . '21 ill 3 i"il I fit <1 P'0 it, fll 2-, 20 1 5i' 29 70 37.001' 5",. 20 2. 500 60.700
\11 I 1 . ... -' il .1 7 1 0 7 .3 17. 1 1 2' ll 1I 2'. 3.0 2.5 39 (10 6.0 00 000 62 000
,I L.I ,0 fi 31 Il 7 31 7. 17 0c) 32 rl I :I 1 3 .:2 37.10J 63 00 2L.000 65. 000
.A ,.1-1: .... .1 1, 2 f ,' 1 :o 7 M 2I 1 ILI :il ill 1 2,' 32 71 I 8 lio'l 61 00l 2.000 66.000
'lnlIi....... 11 i.4ilT. M) 7 0 314 '0 17'. I-l-l2 4.' 12.65 2.'2 1 2 l a uOl1 '5658.45 20 I.O 606.600
.I,1ly % l., .. 21 I' : 7'. 7l 72 31 1l1 17 Si 27 91 1 2*6 2'9 21 3q.800 .8.61; 2.015 60.660
'6r..nd [.a-tl. iw'o .itj7q Ou 33 71 1.012 75561 2%"l'. 75 34.W19%4..3. 1,.217.750 1,99..75 68.3.501,967.100
t r.n,.r l iH r- 6 |,
,>. ....... "2-1 x4 32 6m 1 12 .33 76 18.71 31 66 1 15131 M1 40.92 63.29 2.28.5 65.570
On I _,._ h.ld u- milk -- pu-IIndsI.
auOne. too held up milk t7 puu-ndsj.


Naturally one of the lir.,t qiwestions asked wvhen a dair N-manI is 'oin-
sidering the installation of miilking machines is: How niii; l tillie will
be saved byv their uise' InI tlie expel riment outlined ah ii one mano
performed the milking. 1 cow milker being u.ied in case of lit- Ilt-
milked by mnachinery. Tin machine was operated lby a 1 -hor-epo\ (,r
electric minotor. By referring to 1 anid 2 tie rtile dr cianiii readily
compare from day to day the titoe rtviiired to niilk 1hv the two methodd..
A glance at the general averages for thiriv dav, -hows tliht tlhe
average time required for one Iiana to ulilk 4 rows with the iniachilne
was 13.i12 minutes in the niornin. anind 13..'57 l minute, inll tihe vi'llillg',
or a total of 26.5i_ minutes- for the dat%. Tliec, fig'ure-, incllide tlie
time used in putting the l aie i in .iiplace and atdj iit iiig tll' teit .Ulp-,
about one-fourth minute per cow leWingl reqtiired to a ljiilt them
In considering the timnie, the amount of Iailk secutird should al-, I e
considered. Other things heiig equal. vow- prodiicing a larc a inioutnt
of milk require the nio.-t time to perform the milking. In an-,e of the
4 cows milked hy hand it will be noted that it took an average of
21.88 minutes to milk themin in thIe morni tig and IS. 71 iniiiites in the
evening, or a total of 40.5.) IniLnutes for th d:ay'. '[here wa- therefore
a daily saving of 3.5 minutes per cow. or 14 ininute, on i cow.. thru
the use of the machines.
It should he rioted, however, that the time -i\ ed v\ the enlploynient
of machines was not the reiult of greater ,pevdl in ntilking-, bit in thlie
operator's ability to milk 2 cows at onie. Indeed, one muati can look
after 5 machines milking 1i cows at once. tiu, greatly increa.i-ng> thi.-I
saving of time. (See experiment No. 2.)
SpIed If l,/' /e can be adjusted so that the action will be fast or slow; .5i to I;l i pul-a-
tions per minute. is the rate usually recomninliided. The mIore rapid
the pulsations the faster the machine will milk. up to a certaill limit.
The writer saw one cow, giving a good I how. minilked ali-olutely clean
with a machine in 21 minuiites, thenulllber of pulsations beiilo. 150i per
minute. It is believed, however, that. ,ticEh rapidly nilkinig.. for an\
length of time h:i. a bad inlnuence upon the Cow and after, a time she
might object to the mniachine and rfitus, to give dowii h!r milk.
Cows vary greatly individually, and it is the bet plan to adjust. the
speed of the machine as closely a, possible to thie re(qulirnients of each
cow. Cow.s, with short teats. can heI milked with the macillhine ,et at
greater speed than cows with large, lung teats. The ordinai v type of
11522--N.j. 92-u7--j


Ayrshire cow, for example, can probably be milked by more rapid pul-
sations than the Holstein. Those acquainted with milking these two
types of cows by hand know this to be true, and that in milking some
cows the milk is ready to be drawn as fast as the milker can manipu-
late the teats.
While the machines were in operation the attendants massaged the
udders of the cows and watched to see that they were milking freely.
Care was taken to treat the animals as nearly as possible the same at
each milking, so they would become accustomed to the machines.


The yield of milk is perhaps the most important matter to the dairy-
man. Any method of milking that has a tendency to decrease the flow
to any appreciable extent can hardly be considered practicable. This
point was studied for a period of thirty days in this experiment with
the milking machine. While a much longer period is necessary to
settle this question, the results secured indicate at least what may be
expected when the machines are properly handled. In this test the
cows were carefully handled, care being taken to adjust the teat cups
to suit the individuality of each cow, also to use cups of the same size
on each cow every time.
As already stated, two lots of cows were selected that yielded prac-
tically the same amount of milk. Referring to Tables 1 and 2 it will
be noted that the total yield of milk for 4 cows during thirty days was
1,898.75 pounds from hand milking" and 1,960.25 pounds from machine
milking," not including strippings-a difference of 61.5 pounds, or
3.24 per cent, in favor of the machine. A study of the yields of the
different lots of cows for the different periods shows that Lot I, which
started with hand milking, gradually decreased in milk flow when
changed to the machines and also continued to decrease when changed
again to hand milking. The yields of Lot II, which began with
machine milking, show that these cows decreased when changed to
hand milking and materially increased in yield when changed back
again to machine milking.

aOne cow held up part of her milk one day (see Table 2).
b One cow held up a small quantity of milk a few times and waa finished by hand
(see Table 1).


The yields of Lots I and II for the three 1i-day periods were as
Yields from uhimi inCiflki.ii oid i'd /o iilkiiqg cwuipared.
Lot 1, 4 cows: Pounds.
First 10-lay period, cows milked hy haid ............................. 653. 65
Second 10- lay period, cows milked hy I IIa hI|II ..... .................... 605. 10
Third 10-day period, cows milkeld liy nhainil ............................ 5S6. 45
Lot II, 4 Lows:
First 10-day period, cows milked liv machim- ......................... ,61s.30
Second 10-day period I, tows imilkr iy I hand ........................... i?.--*. 1)
Third 10-day period, cowis machine ........................ 6,,i. s5
As the cows of Lot II inTrew;,ed in yield when changed back aI.-ain
to machine milking in the third period, when the natural tendli'-v
was to decrease owing to advance in lactation, it ap)pe-Ar-, that tlhe
machine had a favorable influence upon rhe production of think lot of
As Lot 1 was u-.ed during two periods of the hand-milking test and
in only one period with the machine test, and Lot II the reverse, a
fairer comparison imay he drawn by averaging the yields where the
same lot of cows was used twice in either test. The result of thiis
method of comparison is shown in the tabulation which follow-,:

('oinparisorn ,f the wilk ;/i(d of the two li,,ls (if Cron- (nol ini luoliny slripfpinny).

Hand milking: Ponnfls.
Lot 1, average of first and third periods............................. --------------------------620. 05
Lot 11, second period ..------------.------.......---.................--------------------.65s. 65
Total ...........--------------------------------------------------................................................ 1,278.70
Machine milking:
Lot 11, average of first and third periods............................ -------------------------l177. FI)
Lot 1, second period.............................................-----------------------------------------.. 60.. 10
Total ........................................................... 1, 2s'2. 60

It appears that the yield of milk, not including .strippings, amounted
to 1,27S.7 pounds from hand milking and 1.282.61 from machine milk-
ing, a difference of 3.9 pounds also in favor of the machine. This
further comparison will serve to strengthen the conclu.,ion already
given that when the machines are properly handled and carefully
adjusted to suit the needs of individual cows the yield of milk com-
pares favorably with that of hand milking.



A machine that does not milk cows clean, or at least as clean as the
average farm hand doe-, is of but little service to dairymen. This
point wa- tested a- thoroly as possible in the experiment, just described.
The man who milked the cows by hand in this experiment was
in-Atracted to milk the cows as normally as possible and not to go-to
extremes in either direction. It is believed that a fair trial was made
in thii respect.
Referringt to Tabloe 1 it will he observed that the amount of strip-
pings wa, fairvl uniform from day to day in ca.-e of both hand and
machine milking. A comparison of the amount of stripping from
each lot of cows for the three lu-day periods is shown in the following

;uIIIJpari.oII of *iimoul ol'f stripping in hand arid machine inkilki.

Hand mnilkinr: Pounds.
Lot I, fi rt period ............................ --------------------------------------------26.50
Lot 11, second period..........-------------------...-------..---..----------- ................ 21.70
Lot 1, third pe -ri,,"1 ................................................... 20. 15
Total ---------.................-------------------------------------------............................................ 68.35
Machine milking:
Lot II, first period ................................................... 25.20
Lot I, -econd period------..........---..-------------------------------......................... 14.00
Lot II, third period ......--------------.........----..----.--...-----------------.............. 22.70
Total ............................................................----------------------------------------------------.. 61..90

The total strippingo- from hand milking for the 4 cows for thirty
day.- is shown to he 68.35 pounds, and from machine milking 61.90)
pound.s. or 6.45 pounds less for the machine. The average strippings
per cow for each milking wa- 4.55 ounces by hand and 4.12 ounces by
maihl ine.
The compoition of the milk was not determined in this experiment.


This experiment was conducted with 2u cows selected from a herd
of 65. All kind., of cows were selected for the test, including hard
and easy milker-n, heifers, and mature animals, and fre.-h cows as well
ais those advanced in lactation; also including cows of nervous temper-
ament which it was known did not take kindly to the machine. This
was done in order that a thoro study might be made. The 20 cows
were divided into two lots of 10 each, which we will designate as Lots
I and II.


Lot I was milked by hand and Lot II by machine for ;i period of 10
days; the methods of milking were then reversed and Lot I was milked
by machine and Lot II by hand, 2 dayz being allowed between tlhe
periods to make the change. Five machines were u.-ed to milk the
10 cows. These were handled by one man. One man also milked
the 10 cows by hand the greater part of the time. Whenever more
than one man was employed the results were put on the ba. is of orm
man; that is, if two men milked the 10 cows in 4io minutes this was
considered equivalent to one man milking SO minutes. Thi, exper-
iment differed from the one previously described in that more cows
were included and less attempt was made to adjust the teat cups to the
different cows or to use the same machine on thile same pair of cows
every time, this matter being left largely to the dairviman in charge.
These points will be considered in studying the results.

TAI.II. 3.-- 1 O.,VIij in',I "' I 0 'f ili,, fi'4i, I (f l f I 'aI ,iJi.i.lf f16 111 f4r.1 h()J III /Il IInC'l,; tI" lot I ;.

Tile iowl. iilad dlav.

LOT I. 11 lI', 1 .

July 21; ..............
July 27..............
July 1 ..............
July 29 .............
July sn ............
J tll i' : .1 ........
August 1 .........
AugRList 2 ..........
August 3 ...........
Augu't 4...........
To IIl ..........
Average ......

Titne re

tifj. 1.1
7i. t
7U. I

75 0

7.4i 0
.ft 0

Motit ilia.

Yield.l I

mill iT

J'ni, ls /A I. I',,.. .

121.I I lit I 122 ut;
10)1. 1 I. 00 If) - Jill
123.1 2 Oit 126 IJi
110.0 i.A 120. rNl
I I 'I i tti ]1 -.1 I.
121 0 1. ho 12.'.i)
1 1.5 3. Ul 121. hli
110 U l.00 i 11 Ott
121.5 1.00 121 61
117.0 1 .'Ii 11S 60

787.0 1,172 0 1 1 AI
7'i 7 117.2 1 .Ii

", lll,,i-llIl.,.l.

Fill I ,11
1:i I ,, lI it,

;1.7 01 3.4I

.1 li1) 1 ,i :c;
;. 71.1 86 .'"

STii 711 71l
.. II 4 7i
3 -U I

1, 1 i fl . . . . . .
I I S :4 7u 4. .,'4


IT i. .

lr F l
milk. i g, | til.

72.11 117. :1 I. UO 118. 'rl1
'i Li0 9', 1li 2.111 ill i';. lli
so0 01C o (1 I .2 5i0) lQ. 'ILI
7 1lu I ltl .11I ; I ill) 111.1 al(0
710. L.I 11.3. ',.I i 1 'd1 11 .5. UO
74 111 17 tat' 2 Ji 2'' Ill
7"1 Ilt I L1 UI) 1. ill 1l 11 .1t
NI 11 IO 91.00 1 tI: .2 J' Ia
T7 t. U l] IU.0 1 :", lli.5i)
Iu I u I 1u1 .00 I :IL 10)2. :',0

7111 ll U I08. hij Ii. 00 1,034. -)0
71 '0 101.i'a 111i11 103 .,

a 'lt)lll[I"lli h I

i .a,; T I I II T' "
]l--,, .'> )l,' t I 1"11" 1"

' i I it Jl'I' it I i.
4. 1i11 j I 1 tI
t.Sij S 'i 1.34 till
.3. 7U 1'. h -7,i U U
I.l11 .'.9, 11: IN W
1. OUJ ; ,i; no 0u11
9 14.11 1"46 1.l).
.', N 5. I 1"'4 lil.i
i,. ;1U .. 117 I 'ltI OIlI
.. 1f 1 8 6'2 141 I'll
3 *i0 s. jil 1:,5 I)


,'ir-t i j t,' lna l.i
))i1l l ll l ( -.

* "i .itf[ll1,i n ll l.

iili. IN
I l'*.l 'i l,,I
| 1",111 .

-- I

23 rill
1-11. uil

*-I'. IIN

221 ',i1
*Jr "'il
22ui. IJuO
211. 611
'211'4 tiO

.2. ItO
t. Il

i .(IL
4 'ti

I 00l
'2 .'iC
I rll
I 61l

2J 00
.1 OLI

.. .... .. .... 1', 017 Lil 2, '1 ". '",) 311. '50
.+. I > 62i 14', 70 219. t'1 S4 0'

LOT II1, ILl 1'OWS..
Auglust7 ............ h .0' 1lii 0 1.00 117.U0 L lii) ".37 ,I 01) 112 00 1 ',0 113.5 Bt .3. Sj P..:17
AugsI)s 8 ............... Pl i 12 3.] 1 1. ,a0 121 ,lMl .! 40 oii 10 100 a 2. i0 I1-.UU 1 .1 0 41
Aug'ii !) ....... .... 1u U 12..i1-1 i UU 1211 110 3:1 i l) I i l ill Iti. l tU. 10 l.r I0 10" i'l 3 41) 4..3.1
AUffti-t 10 ........... 9U. o lli. 0 1 IU 117.1 iJ .1 7U 14..'r X1I.LIIJ. i 1 11 U) 4.60 111 .'iL ...O 4.:12
Alugust 11 ........... 0 0 107.0 2. OuU tll. il 3 70 8.67 7l 00 1 17.7 ItU 2.00 U 10 LIU I 4 10 19
Allgtusit 12 ............ 90.0 Ill. C 1. 10 122. U1.1 3 7n 8. 17 7"5.00 ,I Jii.0 1 i lO10 0 .,0ti 3 i;0 m' 41
Aug)it 13 ........... 80.0 111.0 1.r0 112 6C 3.CO 84..17 A.O. 00 91 U0 1.11, 92.0iI 3 '90 1 4.
Atuglit 14........... S1.0 111.0 2.00 1.J JO :5.90 8.A1 70 00 10,t (0 1 30 101.50 .1.8. I .4:7
Augttst Ir .......... 775.0 U 17. 0 1.10 ll0- CLi 3.10 P r5 1 7:3.00 97 00 3.50 1li.) 51 3.211i ;i
August l ............ 76.0 11. 0 2 00 121.O -1.00 .41 I 0. tO I 104 Il) 1.0 O 105 "S .1 00 ., 4.

Total .......... 834.0 1. 15t. 0 17.110 1. 1 7. . .... ....... ..76&.iJl 1,024 50 21l.0 I1.114" 00 .. .... ........ 1,
Average ...... 83.4 115 6i 1.70 117.:30 1 3. '.'i 8.4 71i.A0 102 45 2.1 l15 104 .50 3.76 M. 44

Grand lol.... 6'21.u 232.8 31t. 1 3.59. 60..... ........1,478.00 2,048.00 36.60 2,079. 10 I ......... ....3,
Generadlo average..... 81.0 116.4 1.57 117.97 3.7 51 73.90 102.1 1.82 10.97 3.5 .5
General average. 81.0 116.4 1.,57 B.9 "85t 739 102.16 1.8 103.97 3.8 .5

I',,,,,.,11. II 'e, CI. p, 1 1.
"11l it 4 1fu .4t i
23J3 ."0 .1 7l) 8. 1
.-22 1il a 3 Nil .sl
225 Itt a 7I' ,.I.l
JJ! Jill .7 ,'.1 ''8
221i. ila 7.' 3 .11

21..i "'0 .7. X.70
v2.tlu I9. U '.61
2,221 ta I ............
222.10 3. 42 8. "I

1a 0 30 22A. Ol O 2.0L 230. fill .,0 6. 37
l1i0 Uil 224 UIj 3. 0lu 227.--0 3.6U F) 47
170. JO 211. '.0 fi. hli 2.37.0 3.45 8. 38
170. Ul 22.3 1i0 5ri. 22. Si0 3.7,A; '.44
15M UO 214 lit) 4.011 221.. iO 4 0.1 Hi 53
hi. 00 220 Uil 2 50 22J. ;Lu j W 8. 48
165.00 202. 00 2.50 204 ;Au 8 4 8.45
]5. 00 211 0I0 : 501) 214. i0i) 3 'iN .'14
414. 00 204. iu 4. 50 20. 1.S 8 I' R. 19
141; 00 223.00 3.50 226 iO 4.00 8.44

1.02 00 2.180.50 6 37.,`0 2.218.00 ...... ......
O160.'0 21"41.05 8.75 221. 1u 3 72 8. -lli

1199.00' 4,371.00 ....... 4, ...... ....
154.J0 218.55 3.40 221.95! 8.77 8.62

IA, too OL,








Average ......

Grand total .....
General average.

202.0 1 ,I'l 19.70 1,01.3i. .. ....r i .....
202 103.4 1.07 106.45 3.50 I 5 66

:S8.0 2,155 0 44.70 2,210.50 ". -...
19.4 107.7 2 23 110.52 3 30 .1

T i1. 10 cows.

2G ............ 23.0 97 0 1.50 95. S0 3 30 s 45
27 .............. 12 1) 93.0 3.50 S6.5I 3 00 8.49
28 .............. 22.0 110 0 2.50 112.50 3.41' 8.82
29 .............. 20.0 116.0 2.50 11X. i) 3.10 8.43
30.............. 20. 1 100 0 f0. u0 lIth. LIt 3 60 ?, 88
31.............. 1.I 119 .5 1 50 L'1.00 3 10 8 51
st I ............ 17.0 115.0 2 00 117.00 2 70 ,.39
st 2 ............ 15.0 i e 130.0 2 UO0 132 00 3.20 73
qst3 .......... 22.0, t110. 15 1.0 112.'.0 3.20 .50
.,t 4 .......... 20 0 e el3i0 0 2.01 132 U0 I 3 20 8.50

Total.......... 16 0 1121 0 29.00 1,14t, 10 1..........
Average ...... 18.6 112.1 1 2.50 11 G0O 3 2u 57

IT 1. 10 COWS.

IS.t 7 ...........I 17 0 112.0 2.00 11.00 3 70 8 13
i1 8 ............ 20.0 123.0 1.0' 124 L1l 3 20 9.17
.1t 9 ...... ..... 23.0 e ]12.0 2 UO 14.I I 10. 8. 45
s ilt 10 ........... "20 0 9.. 0 2.50 I100. ( .0 3 40 P t4,
st 11 ........... 18.0 11.1.0 'I lill. :.0 3 7o' 8.70
at 12 ........... 16.0 .5.0 l.:,j 8rj.:',ll .i 70 8.41
, 1.3 . ....... 22 0 e98 u 1.50 99.50(1 : f.0 ;
.t 14 ............ 25.0 100. 0 6.00 106. u0) 3.50 .iS
St 1I.. .......... 20.0 102 0 l.511 LI 50 330 e 64
9st 16........... 21.0 103. U 1.20 104 20 3 2u 4. 7ij

101.50 1.50 103. 10 3.50 t,. 4 3.0 140 19s 0)U
94 00 2.00 96.00 4.00 < '.. 39.00 1s7.uU
106. UOj0 2.501 108.5 0 3 90 S 29 39 (00 216;. (iI
90 00 1.50 91.50 3.40 S. '7 40.00 2011h. 10
t101 00 1 50 102.50 3.50 K 59' 31. iU 201 U0
A7 00 3 50 wO..U 2.70 ,8.-14 2.' -'Oh 50
90 Ou 2 h0 92 .90 3.40 1 .'. 34 00 209 fit)
106. 00 3. "U IU'. ,.O 3.5'.9 5. & 53 2.$ 40 2.136 U0)
.M7.00 o 1.'l0 8S .' 4 uL A 71 39.00 197.,50
10 Ou 2J UO 110 00 ; 3 N'0 ,S 57 40.00 236. l0
970 50 22 t'0 I 992 50 .... .... ..r', 50 I 2.0l41..50
97.05 2 20 'j. 25 1 3 L0 8 .94 31. 5.5 200 19

3 Oil
5 50
5 OU
4 00
7. 'S,
9. OnC
4 51
:) A0
31 UU
4. U

I 70

201 501 3 I A. 46
1 2. W :L. .5 1 .51
221.00 3. ", .56
'hi) 00 3.2.5 8.50
208 Su 3. '.5 .74
211 50 2.1) %. "3
2U09. 50 3. 0'i X 49
2-41.50 3.3' IS.63
200 5n a '.0 m. 1l
212 1O 3 "iu X.54

2. 1:S 50 . .. ........
' 213. X5 3. '7 x 55

1F 00 94.00 1 50 95.50 4.20 .l.69 32 00 20i 6. 0 3.50 209. AO 3 9.5 x. .I;
17 00 102 'JO 00 101.006 j ..I 7.37 37 0u 229.00 1 00 221 00 3. 0 '% 77
21.Ou lU.O 1 00 101 ')0 I 10 $ 33 44 1'0 | 212 :'O 3 100 215.00 3 t-0 x.:l
21 UO 101 00 1 50 102 50 3 Al $ 42 41.Uu 199. o I 4 II) 20:.1 1O 3 1i. $.53
11.00 102 00 2 5r. 104 )0 3.sU A. t7 3 0 U 2 -03. il 3 Oi' 'u; 1 I ,O 1 ,, :.t.
17 00 87 50 1. -0 00 3.."0 .. 41 33 00) 172 50 :3.Uu 175 .' 1 rJ C K. 6.13
12.00 $ 1 0 I i 42.1 .10 4 0O 43 34.001' 179 UL, 2.50 11 50 :1 75 % 63
22. 1U $4.50U 2 (11 4;. 50 3.2uI 2 a3 47 'i0 1M4.5) 00 192 50 .3 :41 x 73
17. it) 92.00 1.100 93.00 1 3 80 1 12 37 0O 194 0'0 2. '.U 196. '0 :. :'5 x. 53
1&.00 93 00 4.50 97.50 3.'-U .21 :39 tU 1. 17l "JL.70 201.70 3 3, .'. 4lb
174 o0'f | 937 Q0 1 RU 955.50 .. .. .. 376.00 1,971. UU i .h 21 2.1)09 20 .0 .. ... ...
17.40 1 93.70 1 ,"5 9 5.55 3 9', i "2 i 37 t,0 1 17.10 3.s2 200.92 1 6 ,0 59

353. .) 1,907.,5u 40.5'' 1,94S. . . ". . 741 50 4,062.5' ..20 |4, 147. 7, ...........
17.67 'l5 37, 2.02 97.40 3 7 K .3 37.07 203.12 4.;26 207 39 3 49 .57

dOne hundred and teri pulafin-.
mi. eOne to 3 cows held lip .'omt- oi th-ir nilk and were finished by hand.
p milk.

20. no
17. ULI
li l10
d 13. Oi)
13. 50
17 00
20. "O

179. :U

oAverage of pereentagem only%
bCoi\ had iriflamu'd ridder, requiring ]'ingrr time to mill
cToo small teal tups used onr cow, eauing htier to hold u



The accompanying table shows the time required to milk the cows
1,iv the two methods during the different periods. In this experiment
one mnan handled 5. machines with little difficulty. The man who
milkedi the cows by hand was uinusiually thoro and took somewhat more
time Ito do, the work than the average milker.
It will 1he nottd that the average time required for one man to milk
the 10 cows with the machines for 21.1 days was 19.4 minutes in the
,morning and 17.67 minute. in the evening, or a total of 37.07 minutes
fir t lie day. The time stated includes the time required for putting
tle machine, in place. adjusti ng the teat cups, and milking; the aver-
oage tine p[er cow being l.1-4 minutes in the morning and 1.76 minutes
in tlI. evening, ,r a; total of 3.7 inuiites for the day.
In the ,ra-e of tlhe 1.i rows milked by hand it will be noted that it
req ired fr the 21 day' a, average of 6S1 minute-4 in the morning and
:,.9 minuilte- in the evening, or a total for the day of 154.9. The
a'cringe time re',liirtd per cow was therefore S.1 minutes in the morn-
ing aInd 7.39 miilltt-s il the ,eveningi, or a total of 15.49 minutes for
thle dlay. On the Ibasi.s of these re-nilts the daily havingg per cow thru
the u-e of the mianhineN amounted to 11.79 minutes, or 117.9 minutes
for I Ie 10 cows. (': rryin- the comparison still further, the saving
for 1;1i cows (the Lumai.ber in thii-, herdI would amount to 11.7 hours per
day if one iman perf-ormimed all of the work, which of course would not
i. pwoible for a herd of thi.- .ize, altho the writer has known one man
to milk 611i cow., with ; machines on more than one occasion, the time
required being about 2 liom.,. If. however, we include the time of
thn- murn w ho rcino,\ed the milk and as-,iNted in manipulating the cow's
udder., the saving, o(f time is reduced to one half, or 5x.45 minutes per
dav for the 10 cows. These figures furni.-h sufficient proof for the
statement that the machines are time saver.."


A, previou-l'y stated but little attention was given to properly
adju-tin', the machines by the attendants in this herd. Further than
this. it was known that 1 or 2 of the cow.-; -elected did not take kindly
to thu machine. buLit it. wa,; desired to have the cows in the test represent
the average of the herd While a longer period than 20 days would
have bt-en det.irable, the result,; indicate, at lea-t, what may be expected
uider the conditions which prevailed during this test.
keferringo- to Table 3, it will be observed that the total yield of milk
for 1n cCow.- during the 20 days was 4,371 pounds from hand milking
a,1111 4,11;2 5 pound- from machine milking, not including .,strippings-a
diference of 30oS.5 pounds, or 7.53 per cent, in favor of hand milking.


This result is not surpri-inig when we consider the carele%. iliininir
in which thile machines were adju-ted to the animals, and that. thi- fre-
quently resulted in the animals holding up their milk. Further, the
fact should be noted that the hand milker in thi-., instanie wa, iiiu-u-
ally careful, taking an average of 7.75 minutes to milk a cow at eah
The results tend to show that where milking" machine, are used
carelessly they are a disadvantage to the dairviman fronm the -;;tandpiint
of yield. The same hold-; true of other machinery on the farmi: the
more complex it is the more care and .skill is- required to -evcure the
best, results; hut with skill and care the more machinery the better,
up to a certain limit. This is brought out in experiment No. 1. where
the milking machine held its own or showed an advantage at every

As previously stated, the man who did the milking in this experi-
ment. was an unusually thoro milker and consequently took nire ti me
for milking than the average milker. While po-siblv it would have
been better to have employed an average milker in this experiment in
order to make a fair comparison, the question ats to whether the milk-
big was thoro by both methods can be made clear. In a fe\ instances
1 or 2 cows refused to give down part of their milk (probably owing
to the teat. cups not being of the proper size). This of course increased
the amount classed as ..trippings. A comparison of thle amount of
strippings (including the amount held up by the machine-milked cows,
as explained above) from each lot of cows for the 10-day periods is as
(; b iperi.,oi of ,taogjv ,f ,,t.4ri;:iqi .- i;, ii.,/,e ',,I .3,,. 2.

Hand milking: ounds
Lot I. first period ................. .. .... ......................... 30. .50
Lot II, -eiond period ................................................ . 5,7.0
T ,atm l .......................................................... 6s. 00
Machine iilking:
Lot II, first period .................... .......... ................ 47.00
Lot I, second period ... ...................................... .. .20
T o ta l . . . . . . . . . . . .. . . . . . . . . . . . . . . 2 0

The total strippings from thle hand and machine milking for thile 10)
cows during 20 days is thus shown to be 6q pounds and S5.2 pounds,
respectively. On this basis the average strippings per cow at each
milking amounted to 2.7 ounces by hand and 3.4 ounces by machine.
In either, case the re,,ults show unusually clean milking.
11522-No. 92-07---I



Ptc :n1a(t/e uf !,iflertf/ ;I mi/k'.--A sample of the mixt milk was
taken at every milking in experiment No. 2 and tested for percentage
of fat hv the Babcock method. The results- of the daily tests are
-hewn inll Table 3 and the average for the different periods has been
bh'rotzught together for ready -omparion in the following tabulation:

P. r,'tiill-,_' ,'l" i.l.. rf in ilk ir,-imrn Im, ham,i 'i'm l by; m bciirie.

lHail Iiilking: Per cenI.
I.- t 1, fir-t pe-rio'l I 10 lays i ............................................ 3.82
Lot II, seronl I'e-ri dl 10 ,lay- 1 .......................... .............. 3.72
.\ ra-r ... .......................................................... 3.77
M1a.lhnie milking:
Lot II. rirt jp-riI 1 10 dlays .................................... . ...... 3.37
Lot I, .-t-i'orinl p eri,.l i 1U0 la s- I .......................................... 3.60
A \ erage ............................................................ 3.49

It will be noted that the overage percentage of fat in the milk drawn
bhy hand for the twenty davs wa- 3.77 and in the milk drawn by machine
;:.49. t conider'aldle difference in favor of the hand milking.
A ,olhiulation of the yield of butter from thle 4,439 pounds of milk
resulting front the hand milking (Table ?.3). with an average of 3.77
pri cent of hutter fat, give.- about 19.25 pounds of butter. The same
amount of milk with an average of 3..49 per cent of butter fat would
yiehld alout 1.ii1.75 pounds of butter, or 14.51l p)Otind% le-s owing to the
I, wer pervn'utage of Ibutter fat presumabVly resulting front the use of the
machlin'-.. If the yield iof butter be calculated from the 4,147.7 pounds
of milk re.ul ting from machine milking, with an average of 3.49 percent
of fat. it will Ile found to be about 169 pound..,. Thus. if we allow for
both the lIower yield and the lower percentage of fat in the milk int] this
experiment, the balance against the machine with 10 cows for twenty
do\.- would hl oiaou1t 26 pounds of butter, or about 13 per cent. This
appears to bIe qjLIit, a1n unfavorable showing for the machine, but further
experiments are necessary to determine the effect of machine milking
on the comlpo-ition of milk. as it is always unsafe to base general con-
clusionii, on the results of a single experiment.
I\ri, ti/,lt .../, toint im.ft."-The percentage of solid., not fat was
determined by means of the lactometer. Test, were made from samples
taken both morning and evening. The detailed results are given in
Table 3, but in order to make a more ready comparison only the aver-
age- are presented here.

"These. tests were made bIy Prof. \V. A. Stocking.



Perceieu tie .'s,.lid.- nojt fril ;n null: draw.irn by Ind atnid bi machine.
Hand milking_ : Per c-nt.
Lot I, first period (10 days) ............................................ S. 58
Lot II, second period (10) days I......................................... 8. 16
A average ..............8............................................. .52
Machine milking:
Lot II, first period (10 days) ......... .................................. S. 55
Lot I, second period ( II da.vs) ......................................... . 59
A average ........................................... : ................ S. 5 7
The final averages shown above for the -olids not fat are very clo.-e,
being 8.52 and 8.57, respectively, for the hand and machine milk.
While further study- should he made on thi,' point, the figures secured
indicate that there i practically no difference in the amount of solids
not fat between machine and hand drawn milk.


first tmune ,ncht;n.' <.q .-It is of intere-t to note how the milk-
ing machine affects a herd of cows the first time it is used. The writer
was present in a barn of about 404) cows on one occasion the firs.,t time
the machines were put in operation. Some of the animals were a little
restless at first, owing to the sight of the machines and the clicking
of the pulsators, but soon they became quiet and reconciled to their
action. One feature which is perhaps a little surprising is that heifers
took to the machines as readily as the older cows. Only one cow in
the herd in question made any disturbance at all while the machines
were being attached, and this was ldue principally to attaching the
machine on the opposite side from that on which the cow had been
accustomed to be milked by hand. Thi., cow. however, soon became
quiet. The majority of the cows appeared to like the machine-, and
stood quietly chewing their cuds without manifesting any discomnifort.
A careful examination was made of the cows.' teats and udders in
several dairies where the machines had been in operation for several
months (in one case over three years), and no ill effects were di-covered.
Xcrvou.R cows.-On two or three occasion-, it was observed that when
strangers came into the barn during milking time a cow would appear
frightened and refuse to give down all of her milk. Thi.- occurred
with cows being milked either by hand or by machine. When the
machines are properly adjusted, cows of a nervous disposition do not
seem to resent the method.
KiicrAin co,,s.-The writer, after visiting from time to time several
herds where tlhe machine. weri-, in operation aind oberving tlie ma-
chines working continuously in one large herd fir a month, failed to


find any cows that could not IeP milked because of the "Kicking"
habit. Reports from dairymen who have had experience with the
machines confirm thi.- statement. It is therefore believed that the
machine, give le-,s trouble with such animals than the hand method.
Iaurl ,,/,,.....-The hard milker and the cow with small teats are
lmilked much more easily and quickly by machine than by hand, and
with the installation of. milking machines there will be les-,s reason for
disposing of .,such cows. With the hard milker it. is simply a question
of keeping the machine at work a little longer, and with the small-
teated cow care must. lie taken to have the teat cups of the proper size,
and the pulsations may also be a little more rapid.
l'if,..--The results already secured indicate that the milking
machine is particularly well adapted to heifers. Since milking is an
artificial process, heifers that have never been milked by hand, as a
rule, become much nuore quirkli reconciled to the machine than older
animals, which have been milked for years by hand. The latter often
have their udder., more or less distorted and drawn out of shape by
the hand method and do not as readily adapt themselves to the machine
6',,,r- t/,, it' /to 1 in ilk/t (I t/h the t '/iin.c '.-Occasionally a cow
for -one reason refuses to give down either a part or all of her milk.
This does not seem to be due to nervous temperament. It is possible
that the change from hand to machine milking is too radical for these
particular individual, and that they need more time to become accus-
tomed to it. Such cows do not make any objection to the machines
beingrattarlched to them, butsimply st.and quietly and allow the machines
to i1uip away without yielding any milk. As the cows that give
thi., trouble aire very few in number, dairymen who install machines
uiirllY dispo_.- of them. Frequently. however, cows that refuse to
give their milk at first, milk freely after a short time.

Great cart shouldd be taken to see that the proper-sized teat cups
arc used for each cow. Cows with large teats require larger and
longer lips,. If the c.up is too small the teat. will wedge into it and
not milk: if too large it will not milk properly nor stay on so well.
It hi!s been found that a cow requires slightly larger cups when fresh
thaiti she doe'" when advanced in the period of lactation. When fresh
the uddir i-, distended and a very small portion of it projects into the
teat cup. Later, the udder as well as the teats are softer and more
limp ;and project farther into the cup. During the tests made with
thti maichiines a cow occasionally refused to give down her milk simply
bihc:luse thle teat cups used were not of the proper size; after new ones
were :idju-ted the cow milked out clean. This emphasizes, the impor-
tance ,t' hlingvii cows always take the same places, in thle barn and


using teat cups of the same size at each milking. (Cows will then
become accustomed to the ci ip, and will milk clean.


Naturally the large dairymani will be the firt, to adopt the cow milker
for the reason that his equipment will co-,t liinm le.,s per cow than the
small dairmani. Again, the large dairvyman ha- more at -take and
has to depend entirely upon the hired men to do the work. If they
fail hini the work falls upon hinielf or perhIap, ulpon a ver v limited
number of helpers. With the in.,tallatiowof the milking machine the
large dairyman i.- Liuch more independent, and if necessary cotald milk
a herd of o50 cows without a4,istance. Thi-, would lie next t'o impo,-i-
ble without it. However. there ,eein, to be no good reason why a
dairyman with ait herd of even In or 12 cows could inot, ut-e a machine
with profit. The power re juitred could be secured at -,maill cost, and
the time saved could bIe ued to advantage in working the team longer
on or in other wayv.

The scarcity of milker., and the unreliability of many' of them has
had a tendency vto keep many men from going into dairy farming.
Some dairymnen who have been in the I)Iine,,. have been ol)liged to
give it up for this reason. Great interest therefore center.,, around
the milking machine. especially where the above difficulty exist,.
With the introduction of the milking iachinet only about one-half the
labor will be required to milk the cow,, and it is believed that the
labor employed will lie of a higher clan,, than heretofore and will also
command higher wage.. It i believed also that the advent of the
milking machine will have a tendency ainiong farmers who now have
small dairies to enlarge their plants and to make datirying their chief
busine-s. The trouble ha;s been in tlie pPtt, that too many farmer.,
have made dairying secondary to other work, and1 when anything had
to be neglected it wau alwav, the dairy. For this reason thle profit, from
theirdairies have been mniall. \here te milking machine. have been
introduced they have influenced dairynmen to clean up their barn. aind
take more pride in their work. This naturally will result in the pro-
duction of cleaner milk and perlhap, in moit casWes in better pri.e,..
Any new apparatus which ha., a tendency to improve dairy conditions
should be welcomed by the industry.
Improvements will doublee.. be made in thi.. milking machine from
time to time. At present two cows are milked in the same can. thu.,
making it impossible to secure the weight of the milk from .inigle


cows. A great deal of importance is now being placed upon records
of individual cows in order to determine whether they are giving a
profit to their owner, and this is a movement in the right direction.
If individual cans were provided for the cows. accurate records could
lie secured for each animal. The difficulty of making machines for
individual cows is not insurmountable: in fact a few machines have
already been built which keep the milk from the two cows separate.
Another improvement that it is believed would add much to the
practicability of the machine is a teat cup that could readily be adjusted
to tents of any size or shape. At present cups of different sizes are
used to meet the requirements of different animals. Some improve-
ments in this direction are already in progress.

A- attention has been called to the advantages to be secured by the
ue of milking machines, it is property pointoutsomeof the objections
and possible difficulties.
Initia'tl 'tlay.-The considerable outlay in the beginning will prove
a serious obstacle to dairymen of limited means; and, even with those
who are financially able to make the investment, it will have tendency
to deter dairymen from the installation of machines until their practical
utility has been fully demonstrated.
C(irrl..x .ir ;mpropi .'e.-As already suggested, the machines may
be improperly or carelessly used. The operator may fail to select and
use teat cups which fit. etc.
L;t ',i'q, 0 i<:wr/,; f.-The machine or some of its parts may prove
%hort-lived. thus causing expense and trouble.
Trii /h1.. 'td1h /t e, -In case a team, gasoline, or gas engine is
ued (as will n-uually be the case), it will be necessary to employ some
one who has sufficient knowledge and experience to run the engine.
To do otherwise is to court disaster. Even with such a man. trouble
with the engine nmay occur any day. Be.,ides, the use of an engine in
or near the barn involves danger of fire, and makes extra precautions
necessary to avoid invalidation of fire insurance on the building.
q'qn/ipqe.x avitl /r','*, chinery there is always danger that some part will break down or get
out of order. With most machinery this is not a very serious obstacle,'
-ince the work to be done can await repairs. But milking is work
that can not be postponed. Attention has been called to the independ-
enve of the dairyman who milks with machines as compared with the
one who mut depend on hired help to milk his cows by hand, inas-
much as the latter may find himself short of help at any time. The
-ituation. however, i-. reversed when the engine or some other vital
part of the equipment breaks down or gets seriously out of order. If


this occurs at or (luring milking time (as is likelyv, the dairyman who
has installed machines, with 40 or more cow- to milk, will find it very
difficult, if not impossible, to bring in milker.-, enough to do the work
by band; and the difficulty will be aggravated if he loses time in
cessful attempts to repair the machinery.
COlanii(i H and cart; of the miw/,,x.-As this matter properly be-
longs in the second part of this bulletin, it need only be mentioned
here as one of the difficulties which will demand the most seriou-
attention of the dairyman who may attempt, the use of milking

It is believed that the present investigations- have yielded much
valuable data, but they have been too limited in scope and time to
justify final positive conclusion,, even if the results had been uniform
in their indications. The fact that they were not entirely so empha-
sizes the need for further investigation.
Un ..e/tb, que/hmnx.-.lJust when and how milk is formed in the
udder of the cow, and the influences favorable or unfavorable to its
formation, are subjects which are nut well understood. Whether a
purely mechanical device attached to the cow's teats to withdraw the
milk from her udder will stimulate and favorably influence the forma-
tion of milk as well as the hand., of the living milker must be consid-
ered an unsettled question.
374tt vft milk.-In tile matter of yield, experiment No. I gave a
result slightly in favor of the machine, while experiment No. 2 gave
a result slightly unfavorable to it. But it. must be conceded that thee
experiments were too limited to Nettle definitely the qiue-tion of yield
even for .-hort periods, while the eflct of tlie coitinumou., use of
machines- during full lactation periods wa,. of course, nut tested :It all.
m',,poXilin of f/ic md/k.-The coiomposition of the milk i-, a matter
of as great importance as the yield, and the effect on compo-sition, of
the means and methods employed in milking, is i part of the unettled
problem enunciated above. In experiment No. 1 the composition of
the milk was. unfortunately, not tested. In experiment No. 2 the
milk drawn by hand showed a considerably higher percentage of butter
fat. than that drawn by machines. It would of course be premature
to conclude from thi.s single test that machine milking will have an
unfavorable influence on composition of the milk, but the need for
more exhaustive investigation is certainly apparent.
Consideration such as, the foregoing will naturally cause practical
dairymen to hesitate regarding the installation of milking machinery
until further careful experimentation yields fuller information and
justifies more positive conclusion.,

In order to have an expression of opinion direct from the dairymen
regarding the use of cow milkers, a number of questions were sent to all
dairvmen who were known to have tied machines for any length of time.
All of the 11 dairymen who reported ..aid the effect of the machines
upon the teat- and udder of the cows was favorable: likewise the effect
upon hard milker.-, nervous cow., and kickers.
Nine reported that heifer.5 adapted themselves readily to the
maclhine.: 1 .tated that heifer., took to them more readily than old
cows, and 1 reported no experience. Of the five instances where 1
man handled 2 ni machine.,, the average number of vows milked was 23
and the average time required to milk them was 47 minutes, or prac-
tically 2 lninutes- per cow. In the one instance where 1 man han-
dled 3 minchine- he milked 31. cows in 601 minutes. In the case where
2 men handled 4 machines 27 cows were milked in 41) minutes. In
the two in.,tance.% where 2 mnen handled 5 machines they milked an
average of 52A'., cows in 684 minutes. Where 2 men handled 6 machines
the time required was 1 minute per cow. Again where 3 men and boys
were just learning they milked 31. cows in 55 to 75 minutes.
Some of the advantages of the machines reported were less help,
les-s time required, and more and cleaner milk. One dairyman reported
the co-t to he a dkiadvantage, and another considered it a disadvantage
to run the gasoline engine in winter.
From 1 to 4 cows in the different nerds were reported as refusing to
give their milk with the machine. Some reported having this trouble
at first but said that later it disappeared.
Eight dairymen out of 11 did not think it necessary to strip the
cows after using the machine, 2 thought it advantageous, and 1 simply
stated that there was very little milk left after using the machines.
Six dairymen stated that they found little difference in the amount
of milk produced, whether the cows were milked by hand or machine;
4 thought the machines increased the flow. and 1 stated that the effect
of the machines on production was good.
All of the dairymen reported machine milking to be superior to hand
Since the experiments described in this bulletin were conducted
(August. 1905). the condition of the milking-machine industry has
greatly changed. Certain improvements have been made. For ex-
ample. the milk ports thru the pulsator have been enlarged; a filter
between the pail and the stanchion has been introduced, greatly reduc-
ing the number of bacteria; and the surging of the milk in the tubes
ha, been prevented. The sanitary features have also been improved.
Over a thousand of the machines are now reported to be in use.

By W. A..rocKI,, Jr., M. S. \.,
Bacteriologist, Storrs Agr;cultural Exper;menlt Station; Proqfcs'or of Dairy Bacteriolugy,
Conreciic til Arqricultlural College.

At the present time there is a greater demand (or milk which ha-
been produced and cared for under such sanitary condition.' a. to
insure its reaching the consumer in a pure, wholesome condition than
for any other dairy product. In order to supply this demand the
milk must reach the consumer in as nearly as possible the condition
in which it leaves the udder of the health cow. One of the great
difficulties in the way of supplying consumers with such a grade of
milk lies in the dirt and the bacterial contamination which it receives
before leaving the farm. As our knowledge ,f the laws.of sanitation
and the importance of pure foods becomes more widely disseminated
among milk users this demand for a cleaner antd more whol,'some
grade of milk will steadily increase. One of the greate.,t problems
for the milk producer to solve is, therefore, that of producing such a
grade of milk. A few dairymen are now producing a high grade of
milk under such sanitary conditions as reduce the dirt and bacterial
contamination to a minimum. For this purpose covered milk pails
are commonly used, and great care is taken that the cows, the stables,
the utensils, and the milkers shall be kept as clean as possible. All
this extra care and labor is costly, and the milk thus produced demands
a price considerably above the ordinary market price. This grade of
milk fills a limited demand for those who can afford to pay the con-
siderably increased price, but the problem of the milk supply for our
cities will not be solved until the general consumer can be supplied
with pure, clean milk at a reasonable price.
While the exercise of this increased care and the use of the covered
pail reduce the chance for external contamination very materially and
greatly improve the quality of the milk, the ideal condition would be
to draw the milk directly from the udder into a closed receptacle with-
out any chance for external contamination. This idea has stimulated
in no small degree the inventors of the various styles of milking
machines which have been developed during the last few years.

':, .;*

While it has been possible with some of these machines to draw the
milk tihru closed tubes directly from the udder into a closed recep-
tacle, none of them have thus far proved satisfactory in all respects.
If a machine could be devised which would be satisfactory in its effect
upon the cow and upon the yield of milk, and which can be cleaned
with reasonable ease and at the same time all contact of the milk with
thle surroundings could be prevented, it would go far toward solving
the problem of providing the public with clean, wholesome milk.

In planning this experimental work the writer had three main
objects in view: (1) To determine the germ content of machine-drawn
milk in comparison with that drawn by hand; (2) to test the efficiency
of the machine in reducing the germ content to the minimum, and
thus to determine its value in the production of "sanitary" milk; and
(3) to determine the amount of care necessary to keep the machines in
a sterile condition.
Two farms were chosen for this work; one, a dairy where the sani-
tary conditions were about the average existing in dairy barns, and
the other representing a higher class of dairy barns in which sanitary
milk might be produced.
The first barn selected for this series of experiments is believed to
represent about the average sanitary conditions of dairy barns in the
principal dairy sections of the country. As may be seen by refer-
ring to the illustration (pl. 4, fig. 2), the barn itself was in good condi-
tion. The feeding alley, mangers, and drop were all of cement, while
the .,table floor on which thle cows stood was of plank. The stable had
been whitewashed and was fairly clean, but no special care was exer-
ci-ed each day in cleaning either the stable or cows nor in handling
the milk.
In order to eliminate the difference due to the germ content of
individual ndders and give greater practical value to the work, two
lots of 10 cows each were used in this series of tests. One of these
lots was milked by machine and the other by hand. Samples from
the mixt milk of each lot of 10 cows- were taken as soon as the milking
was completed and were carried to the laboratory. Owing to circum-
stances it was impossible to plate samples at night. The evening
samples were therefore placed on ice until the following morning.
The morning samples were also played on ice as soon as obtained and
plated after they were thoroly chilled. It is of course possible that
there may have been some slight increase in numbers in the samples


of evening's milk before they were plated. It is probable, however,
that there was normally no nppreciable increase but rather a decrease
in total numbers, due to thle natural dropping out )of certain species in
accordance with the so-called "germicidal propertyt' of milk. In
either case the value of the results is not affected, since the hand-
drawn and machine-drawn samples were treated alike in every case,
and it is the comparison of these which is of value. In order to
determine the numbers of bacteria existing in the milk, plate cultures
were made in litmus sugar gelatin.
In plating any sample of milk it is of course a problem to know just
what dilution to use in order to obtain the 1))roper number of colonie.
in the culture plate. In order to be surp of getting -atifactory
results two or three differ-
ent dilution., were used in >
plating the milk, duplicate 0
plates being made from 0 0 Q
each dilution. In most ex-
periments all the plates /0
developed with satisfac- o 0
tory numbers and the aver- D
age of all was taken a rep- 0 0
resenting the number of --0 ,-
bacteria present in the O(
milk, so that the figures ') .
given in this report repre- 0
sent the averages from the O
four or six plates made by
the two or three dilutions
from the same sample of F-. _.-B,,,t-ia tn mo,..i,,f,," barn ,u i.arm No. 1.
milk. As soon as the plate Drawing [rim phi.Itgrraph if eluiin philc xpi-fi ii'v-
culftures were made the seconds in sable at milking tim,. qhowiiing thbe atmopherc
ul'l~ll resi were ml e .e obe well tilled % ith hicfirm andi molI,.
were placed in an incubator
in which a constant temperatureof 7.1: F. was maintained. Here the
cultures were allowed to develop for live days, at the end of which
time they were studied for the following points:
1. The total number of bacteria.
2. The number of acid-producing bacteria.
3. The number of liquefying or enzyme-producing bacteria.
The total number of bacteria indicates the amount of the contami-
nation the milk has received. The number of acid-producing organ-
isms was determined separately from the others because of their
importance in connection with the keeping properties of the milk.
The group of liquefying organisms includes those species which gain
access to the milk thru filth and tend to produce putrefactive changes
in it. It is this group especially which it is desirable to exclude
from milk intended for human consumption, since it is believed that


members of this group are a-sociated with certain digestive troubles,
especially in children. It was believed that a study of this group
might show interei,,ting comparisons between hand-drawn and machine-
drawn milk. The comparative data upon the keeping quality of the
different samples of milk were obtained by taking subsamples as soon
as the milk reached the laboratory, one of these subsamples being
kept at a constant temperature of 70-' F. and the other placed in an
ice chest where the temperature did not vary greatly from 50 F., or
that which is commonly maintained in home refrigerators.

A-; previously stated, one of the points which the writer wished to
determine wa-;s the amount of care necessary for the proper cleansing
of the machines after each milking. For this purpose the treatment
which the machines received was varied from time to time during the
period covered by the tet.s. The treatment which the machines
received is used as a basis for grouping and tabulating the results, and
the effect of the -various methods used in washing the machines will be
brought out in the succeedingg tables.
In the tirst place, it was desired to determine the efficiency of the.
method already in operation on the farm for washing the machines.
This method was as follows: After the morning milking the machines
were washt in water to which had been added some sal soda or other
washing powder. They were then rinsed by pumping hot water thru
them. After the night milking they were simply rinsed with cold
water. The machines were not taken apart. The germ content of
the milk drawn with the machines treated in this way, in comparison
with milk drawn by hand, is shown in Table 4.

TIRI.E 4.-C-'irilmris ni tof rc'ills otf haiid and machlii: milking-machines washt after
ilnrii'i.i mdilkloing h i'ah:r (and sol sodi, 1/ien riensl with wiarmn ualer; after night milk-
ijig, %iw'ply rns.'d itith '.hl wiinttr--mochines. not taken aport.

No. of
Date. expeIri

July 2. ,
....... 4

.lul% 21 ....... I ,

July 2-s ....... 16
.hji 211 J 21

{ 2$
July27 ......{ '
Jul) 2y .... J, 31
Arra go ........
Ar [ig:...

Time of

..... do .. .
.ilo . N
.'Ii .... Ft
. do ....
i..... l ... N F
..... I. .

.... do ... F
Nigzhl . .. ^
Morning.. A H ....

..... .... .

Number of bacteria pe-r cubic
cenuimeter of milk.
Method of
liking !Total bac- bac. Liquefy-
teriam Toria. I Ing bac-
a teria.

machine ...... 105, 1(0 ...................
land ......... 3..233 ; 4.'233 3,466
LHtehine ...... Ih? .. ........ ..........
land ......... 169,200 145. 400 16,425
hidchmite ...... 1. ti46. 100 l,,I4.1.6.'ti 2.7,0
land ........ 79,725 16,400 8,225
lachine...... 12. lUO0 AIl. I00 700
land.......... 5 W%4. 1" 350,750 1,150
lachim e ..... 1,571.200 ..... . ........
land.......... 9j 350 9MA,3b0 6, U25
lachine..... 1,5-.3.200 1,5..025 7,1;5
land ......... 21:,900 184,600 21,775
larhine...... 9.417,600 9, 417.400 200
land ........ 4.179,200 4,107, 900 52,600
lachine...... 1,131,200 1.12-,275 8,925
land......... 128,300 15, 600 9,950
la,.hine.... 2,790,100 2,786. 150 3.950
Hand ......... 768,382 727,154 14,9.52

a Curdled at night; exact time not determined.
bToo numerous to count with the dilution used.

Hours 10 cur-
dling at,-

70 F. BO F.

35 a65
35 a65
32 41
2 0a41
39 6a 6b
39 a65
49 104
49 104
28 67
45 76
51 49
a41 57
60 74
a54 53
37 60
37 49
41 64
41 64


It will be noticed, in the column marked "Total bacteria," that the
machine-drawn milk contained in every case decidedly larger numbers
of bacteria than did the milk drawn by hand at the same milking.
The numbers obtained in the hand-drawn milk are about what might
be expected from the ordinary method of hand milking in a barn of
this grade, but thle numbers in the machine-drawn milk are very much
higher than they should be in fresh milk. It will be noticed also, by
the study of the column marked "Acid bacteria," that the bacteria in
the machine-drawn milk were chiefly acid-producing organisms, in
many cases as high as 199 per cent being such. This proportion -of
acid bacteria is much larger than would result from ordinary stable
contamination, and indicates that the machines were not being prop-
erly cleaned andl that they furnished a breeding place for the acid-
producing species. This would result in the milk that was drawn
thru these machines becoming heavily inoculated with acid organ i.-ms.
It is most significant to note that in spite of the extremely high total
number of bacteria in the machine-drawn milk the number orf lique-
fying organism-s is in nearly every case very much smaller than in
the corresponding hand-drawn milk. When we remember that it is
this group which contains. putrefactive organisms which get into milk
principally from stable filth,and that these organisms producing putre-
factive fermentation in the milk are believed to cause serious diget-
ive troubles with children, the significance of thlie-,e figures is at once
apparent. As a result of the machine-drawn milk being protected
from external contamination the number of organisms of this group
which gained access to the milk was very materiallyv reduced. At the
close of this period, after it was thoroly demonstrated that the care
which the machines were receiving vwas not sthficient to keep then in
a sterile condition and that they served as, breeding places for bacteria,
a different method of cleansing was adopted.

All thle rubber tubes and teat cups were taken apart. It was found
that the long tubes contained considerable quantities of decaying
milk, thus making them decidedly insanitary. In order to cleanse
these they were run thru a clothes wringer twice in order to loosen
and squeeze out any dirt that might be in them. All part, of the
machine were then placed' in a boiler and thoroly boiled. After tlhe
boiling the parts were placed in a weak brine ,solution, where they
remained until milking time. Another series of tests was then made,
during which time the machines received the following treatment:
After each milking the machines had cold water pumped thru them
immediately. They were then washed with hot water containing
washing powder, rinsed in boiling water, and placed in brine until
needed for the next milking. The results obtained from the tests


made while the machines received this treatment are given in Table
5, the first part showing the results from the morning milkings and
the second part. the results from the night milkings.

TABLE 5.-(bomparison of rou/It. of hand and machine milking-machines taken apart
ant <:leapicd; rHin.ed in cold waiter, then hot sal soda water, then in boiling water, qand
placed in /'rinme lill uscd; rinse.l just before use.


Date .'

J u l 2 .. ..... ........... II.
.uly 1 29 ....................
11J u 1 .') . ... ... .. ... .. ....
Aligu-l 1 .............. ..
Augustl ................ .
A elicit I . .............. .
A igu-t ................... '.
A ug u- tr .. ................ .[

Average ............ .......
Pert en [age ......... ... ...

Number of bacteria per t.ubi.
Scentimeter of milk.
N ('o I I[ M' lhl' sJw l --i, --- --
Xptr. mke
ment m In Total be AWcid. b- Liquely
teria. leri| a ing bee

Machine..... 317 .R00
Hand........ 420,750
tMarhine..... 39, 5U0
H an d ......... ........... ..
Machine ....... 622.000
Hand ......... 1, 36. 000
Machine ..... 30. )00
Hand......... 681.500
Machine ...... 332,000
Hand ......... 633. -50
Machine...... 223.750
Hand ......... 1,302,666
Machine ... 242.-2.0
Hand......... .682, .500
Machine..... T7.5W00
Hand......... 197. 500
fMachine 327,412
Hand ......... 693,488
l M machine ..... .... .. ....
lH and ......... ... .

382. 50

1 i5. 000
18. 333
127. 000
5(K, -W
964. 500
a.V), sTOO
36 4


Hours to curd-
ling at-

70 F. 50W F.

43 50
32 39
a30 a3o
a30 49
36 63
36 a54
42 a 102
a30 88
a3lO 100
a30 93
a30) 76
28 65
a30 69
a3Q a8
41 91
1 30 67
35 73
31 66
.:...... ........


,9 37 Machine... 89.400
.38 i Hand......... 113.700
- j 67 Ma(hine ..... 19,000
6 I 6s land ......... 117,125
SI 73 Machine...... 52,875
I 74 Hand......... 84,500
t. J 79 Machine ..... 21.5,750
... ..... .. [ 80 Hand ......... 300..500
t; ,, M Machine ...... 219,250
- ..... ........... ^ ,6 H I nd ......... 5.%8,000
. J 91 Machine...... 295,500
t 7 . .. 92 Hand......... 266.500

.J ..... .. Ma hine ...... 153.629
A r Hand ......... 2410.J54
Machine ... .........
Percveizigi ................. Hand...............

57.,100 2 450
67,300 -2,800
6,62. 375
66,375 9,250
2. 000 3,875
39, 250 7,125
R2. 750 36,125
191,250 36, 375
56,000 34,625
341,500 106,250
256, 000 13,750
227, 500 19,125
81,079 15.200
15. 5'29i. 30.152
52. R 9.9
64.8 1 12.6

aCurdled at night-exaci time not determined.

A comparison of the column marked "'Total bacteria" in the above
table with the corresponding column in Table 4 shows a very marked
diminution in the bacteria found in the machine-drawn milk. While
the average for the machine-drawn milk in Table 4 was in round num-
bers 2, 790,000, the average in Table 5 was 327,400 for the night milk-
ing and 153,600 for the morning milking. At the same time that this
decided falling off in the numbers of bacteria in the machine-drawn
milk occurred, the bacteria in the hand-drawn milk in the night


.5 Ip!I

30 rz1j
so 1z41
27 37
a41 113
34 85
32 65
38 76
.37 ....
29 ........
36 a 6
36 "65
32 78
29 51
35 72
32 63


samples, as shown in Table 5, was not materially smaller than in Table
4, while in the morning milk the numbers were decidedly smaller.
These differences are no greater than would be expected in any series
of bacterial tests taken under similar circumstances. In tlhe morning's
milk, as shown in Table 5, the numbers of bacteria were also decidedly
smaller in the machine-drawn milk. The most important fact to be
noted here is the changed relation existing between the bacteria in the
machine-drawn and hand-drawn milk. As shown in Table 4, before
the machines were cleaned the milk drawn thru them contained many
times more bacteria than did the hand-drawn milk, while after the
cleaning, and with the brine treatment, the machine-drawn milk con-
tained approximately only one-half as many bacteria as were contained
in the milk drawn by hand.
A study of the acid-form-
ing organisms reveals the /---' '" .'.
fact that it was in this 7 .
group that the decrease / 0 - .
in numbers took place. .0. o : '--(- .
While in the machine- 'c o o
drawn milk, in Table 4, 0 U "Q'" Q U
0. C, o ".C 0 Q.. .
there was an average of o o Q .0... .
over 99 per cent of acid- . o
producing organisms, in .0*,. 0" 0 o k
Table 5 the percentage of .- .
o'\ *. ,., ".
these bacteria was 36.4 . D-
(night) and 52.8(morning). o
This decrease in the acid- o .0 '
forming bacteria in the ima-
chine-drawn milk in this
series of tests com pletely v 2- .--Bt tlr,.L in maehint-ilrawn milk 1U4- cnl.,ni,- per
0Oplalit in experinmiet No. 37 isa,- Table 5bi.
reversed the relation exist-
ing between the bacteria found in the machine-drawn and hand-drawn
milk, as shown in Table 4. In this s-eries of tests it will be noticed
that in almost every case the machine-drawn milk contained decidedly
smaller total numbers of bacteria than did the corresponding hand-
drawn milk. The same relation exists in the acid organisms, the
machine-drawn milk containing both a lower total number and a lower
percentage of acid organisms than did the corresponding hand-drawn
milk. The night's milk as shown in Table 5 contained an average of
36.4 per cent of acid organisms for the machine-drawn milk as against.
53.7 per cent for the hand-drawn milk, and in the morning's milk
these percentages were 52.8 for the machine-drawn and 64.8 for the
hand-drawn milk. Essentially the same relation in regard to the
liquefying organisms in the machine-drawn and hand-drawn milk is
shown in Table 5 as was shown in Table 4. The average percentage


of liquefiers in the machine-drawn milk of the night samples was 8.5,
while it was 11.4 in the hand.drawn milk. In the morning's milk, that
drawn by machine contained an average percentage of 9.9 and the
hand-drawn 12.6 of liquefiers. The principal value of these two tables
lies in the fact that they show :-tuh a marked decrease in the bacteria
found in the machine-drawn milk. this decrease being the result of the
grentor care used in the washing of the machine.
In ,pite of the greatly reduced number of bacteria obtained in the
machinev-drawn milk, the writer believed that. the machines were not
being properly ,terilized. To tet this, cultures were made byshaking
sterile water in the rubber
t tubes after they had been
washed as usual. The plate
cultures made in this way
5c show d that the short tubes
and the ends of the long
ones contained only small
S- numbers of bacteria, but
So that the central part of the
three long rubber tubes
was still filled with bacte-
o ria, which were not being
killed or removed by the
method used for cleaning
^" o the machines.
C A further test of this
point was made in connec-
piG .-- ..,., ,,ni.nhir.-.Ir,,, milk 4 o,,lk pfr tion with experiments 77
pla [,: ,n t-p'fl rN purirt \nr 101 I-cee Tnbl tr.C.
and 7,S by milking two cows
with an entirely new machine. The milk thus obtained showed a germ
content of 17,612 bacteria per cubic centimeter. At the same time the
milk drawn into the machine which was in regular use contained 223,750
bIacieria. Thik great difference in numbers of bacteria found in the
milk drawn into the old and the new machines, together with the fact
that tich large numbers were found in the tubes used on the old
machine, wa- considered definite proof that the daily care used in clean-
ing the machines wa, not sufficient to prevent their becoming breeding
place- for bacteria. Another change was therefore made in the treat-
mnent of the machines, and the results obtained are given in Table 6.
On these days the machines were rinsed with cold water as usual.
They were then placed in water containing a small amount of pow-
dered borax and boiled for at least one-half hour. The machines were
then taken out and hung up in the open air until needed for use.


This treatment was given the machines on but two days. As shown
in the table, the average for the machine-drawn milk was 2S,5(i62 and
for the hand-drawn 48,125 bacteria pet cubic centimeter. This is a
much smaller number than had been previously obtained by either the
Machine or hand method, but the relative numbers are not materially
different from those found in the previous series of experiments where
the machines were soaked in brine. These, results seem to indicate
that the boiling in a weak borax solution and the soaking in the brine
were about equally effective in freeing the machines, of bacteria.

TABLE 6.- Cjn'par;suia vf reiw i.- t lar it ,inil ,11 11 int h illnm. --i.,'vlh, ,. ristil ,g.;th ofe !
water, buoled in w arn/r ,iilaina iq W e', r, f '/, Ii,,i 1,1, 1, aa ,/ a tail Ip, m/ I.

N Invit i n ,f lri'ri'i'r],, r'r iA -- t oir I .1 n iir
Si T lh jri r .11"i i r ii' -il L. a!, Illi .l-
I *" -~a ni .. II ,l llt L. - ing tit--
DataP. I l'la'l' l.l t1iil .' -,' l ..,, rp.
-lt-I I i,'ri,.. 1l .[l t.k J, *L t- a I i I
rio -7 it....

1 3I'i Niglil . M hill.-. .. ,,z ]2A Jn'1 1. ,1 i g,
AF ll ll- I . ...7 91 ..... I i 1ld ......... ,lt it 1 ,. l7.0 "') I1 .",
I.u g A u l . ,.i m i l . '.iI 3 . -11.11 l .I 1 I Il
ugU!'I ," .. .....1. II. .... 7, ....... ,it, .... ., "7:1 U 1J ... ..
11u2 . .7 . . ii l .... . : 17 ,000 7
I M hit' Iiil'. .. .- .-2 2.>I 7 ]-'
Average.. .. I l il . 1.. 12, I6 L, .2I- 1 .,. <]-, 12 1M.
P ,-,' . l.' K Ih n ,-. . .. .. . ... 17 |.... ... ... ...
P.rcentagee .......... ...... . i ..... .......... . i 3. 3 . ........

aCnr uilta l a li.ght-- XiI'I I 1iI l hi' ,1, i riit l nallll .


On the night when samples 101i and 102 wvere taken, a third sample-
marked in the table liiiA"-was obtained liy milking two cows into
a machine, all parts of which had been placed in a box and subjected
to live steam for 20 minutes. The result obtainedl in this way are
very striking. The number of b)acttri co-ntainefd in th., miilk thus
taken was 7,875, while the numtielr fornm thlie other Imachines was 22,_011
and in the milk drawn Iby hand .51,2511.

7FIFll 1I E.I'MLE "T -I rille: I. HIIINE'S.

At this point another change in the treatment of the machines was
made. After being u-,ed at night they were rinsed with could water,
then washed with hot water, without the addition of any borax. The
results obtained when the machines were thus treated are given in
Table 7. After the morning milking the machines we're rinsed with
cold water as usual. They were then wa-lht in hot water contain-
ing borax, affer which all the rubber parts were placed in brine
until needed for the-evening' milking. The results obtained from this
treatment are shown in Table H.


TABI E 7.--tp:,mril.oaa vf results oif hand ind rnmach;ie milking-mac-hines washit in cold
I-lit r aCid then in hol sol sodu water, no borax being used.

t. No. o Time of
Dil. experi- milking.
ruent' I

A ugu-t ?" .........
A. uII ......... .
A iig li' t i. t .. . .. .
AugU-i 11
A ugi t r .I .. .. iI
A\ L lti-t 1"2 ...... II
A L -i 1 ........

'J7 Morninrg..
9s ... do ....
l.!l .... dne ..
IlH .. . .rii> ..-.
1 in1 A
1 10 II. .rio .!
U1 . .. i i) . .. I
12lib . dl ....
1"2 .... 0 1 ..
12 ... d ......
1'13 .. .. . -.
133 ..... dn, . Il

MIrlhod iof

Machine ..... I
Hand .........
Machine .....'
Machie .....
IHand .........
NMa nine ....
Hand ........
Machine .....
H and .........
H and ..........,

.A-I.... ........ ....... iandi.. .

P.r ni. Nla.-hire ......
P, rd.ent e ........ .............Il.. rid.

aCutIiled at niilhi-- iit1 imen-jl itdtermined.
bNotl curdled Ij, A'gu-i 19.

In four of the experiments shown in this tnble the machine-drawn
milk contained a much smaller number of bacteria than did the corre-
sponding hand-drawn milk.
In .Some of these cases the
difference is very great, es-
pecially in experiments 103
0 oand 104, and 10) and 110,
where the numbers in the
machine-drawn milk were
0 small. In the other three
Experiments, however, the
a o 0 machine-drawn milk eon-
tained larger numbers of
bacteria than did that
drawn by hand. Still, the
averages are decidedly in
0 favor of the machine-
drawn milk.
The results obtained
Fi; 4.-Bactnria in milk drawn by sIean.interilized machine from the night's milk
i 14 .iloniii ;>erplat.l in el xperimneni No. lolA i ee Table 1-. .
where the machines were
wasiht in borax water and .,oaked in brine will be found in Table 8.

Number oi bacteria perculbic Hours to cur-
,:entrimeter ol milk. dling at-

Total Arid Lique-
bacteria, bacteria. bf rig (P F.-W F

2m.G G6 19,666 77,999 37 83
296. 2.O 122, O00 103.375 28 63
5. S;.5 500 625 38 96
] ), 5'0U 2?, 000 32, -2.50 32 63
11, () 2,000 4,12.5 35 58
102, .2h0 5.8T5 19,375 30 o41
72,3 ;5 5,125 6,625 37 a65
. 1. dg 15,75u 9,625 37 a65
f, 12.5 7, 125 9,250 "41 ki)
944,00) .12., 000 92, 000 26 041
x4, 3K. 4, I000 6,37.5 35 ()
:25,37:5 1, t25 1,52.5 35 t)
76,7.50 1,625 3, 01V 041 (b)
42,6-2.5 "_,375 251) 35 (b)
S, 738 10,006 '.15,428 38 76
2-24,1 77,0$9 3r,914 32 I 58
......... 12.0 18.2 .... ..... ...
.......... ,2 3 16 5 ........ .......


TABLE 8.-Comparison of results Iramii nfil maldhi e iilkhiii--ainri;tn'. ir-i.sil i roil
rt' tih'', elien ; in brra.." w'lntr, aw i.l/ t1 'lll/e -itt1 ib"lii i hI ; riihe till i s'il.

No. o ll" 4in lii"i
Dale. ex peri, Mlki milking.
mrot. 1

NillbvziT i, 1 leriitt per c uli" l l r i ,in: to vlir-
tr'lIlniih r ,C[ milk ililIg aIl-

i. \, 14 Li d 711 F)' F

August 9 ... ...

August 10.......

A ugust I I .......
August 11 ........

August 13 ...

August 14 ......



107 Night... l Machine....
I0.7 .. .d i......... i... .....
I n I .. .. .. H ill . ..
1 13 N IIV 11111U.-
113A i .. ,
114 .. . .. I laniil .
119 ..... ',' . M iih lii ... .
1l A i ...... 1 .. ..... .4 ..
1211 . .-I H Ilmid ....... ..
12'.5 ..... lo . N' n hu inif. . *
12:'iA . ... . .... i ... .t .
1.6 ..... .A ..' .
131 ...... i. hi l h i ....
13T2 ... .. d ... H tiu d .. .
137 .... d . Ha i ....
137 di, . . inh ..
I .. ... .......iil ..
1; .... .' H and ... .
iM t hine ....
.. . \ li, m ,
I l Hand . .

15. .75)0
!11. .5tlJ
4t,. 1 .2 -,
19. 2-50
I1 "'. 2 'U
17, 7.j
13 .Utl
9 12"
1. 1 l
49. "7.)
l. 17
I2.-. o2 "

I .'.I I)
E> SllIll

JM Ili ll. .... .. ... .
. Mal" 1 1 \
M 114ld ... .A . . ... .
iH a n r I ... . .. . . .

aCurdle i in iiKght--itx n lini t il il.ti' iiiii' ']

I101 1iI. I LAt,

2. 2'0 3. 00 I 43 '7
1. L25' 1.-250 1i1 ibi
10.5.'100 34.6., 3% 71
13. i(rl0 7.J37) Ali 101
750 !,37') a7,4 Ih,)
7.12:i 1 22'.) 7% 7 i
C., 0 1 5 ",5 (1, 0 76
.6'25 1.7.0 ,75 i,)
12 ,.I 2".' 37- f 37 "51
1 2 2 .2- 0 1 hi
i, 2. fi6o 66 13 1
2 i ,l)j ti)- 49 I1 1
S12, 2- I.I 11. t. n. 5 i?
L.0t O 0 I b I , 1
0 I b I'
1 .'. 7 'l'l'l0l (1 | b\
2"%)0 1.,,2 (bj bh)
;2 11 50 i t'
'.2,') x. 1", 42
1.'27. ,l i l 61 '.,
lh., .,2' I 1.3, l 1 1 tff

9 ', 13 4 . . .
2.' 9 i- 4 .. .. .. ....

' Nuii rurdled I t,. Aiigiit 19

In a part of these experiment. the re.,uilt- are very unich in favor of
the machines, while in the three te'?ts thle (ompi1ri-0ni i, in favor
of the hand-drawn milk.
This seems to be due to an
unusually small number of
bacteria in the hand-drawn / o
milk rather than to any /
marked increase in the/
number in the machine-
drawn milk, with the one
exception of experiment
131. In this case it ise vi-
dent that something decid-
edly wrong must have o<-
curredtogive the milk such 0 0
an abnormally high germ
content. If we leave this o
one experiment out of the
averages we have for the
hine-d n m. a Fh,. --Ba'rretia in mafbhine.draw i mARilk ., (liii tIieS per
machine-drawn milk an a plate in experiment No. li i-e,' Tai>i 7.
erage of 28,500, instead of
225,900, and for the hand-drawn milk 60.225, instead of 58.500.
This would give a showing greatly in favor of the machines, as is the
case in the preceding tables.


In connection with the experiments shown in the preceding table,
2j cows were milked each night with a machine which had been sub-
jected to live steam for 2--I to 31i mininutes. The results of the milk
thus obtained are seen in the experiments marked bh'A" in the table.
It will he seen that the number.-, of bacteria in this milk are very much
smaller than those obtained y' the other machines, running as low as
"-.37., bacteria per cubic centimeter in experiment 107A. These results
,eem to indicate that, even with the care that the regular machines
were receiving, they still harbored relatively large numbers of bacteria
which contaminated the milk drawn thru them. It will also be noticed
that. even with the machine receiving the steam treatment, the germ
content of the milk increased quite rapidly from day to (lay until it :
wa;is about the same as in the regular machine-drawn milk. This is
regarded as an indication that the steam treatment given was not suf-
ticient to completely sterilize this machine, so that the bacteria gradu-
ally accumulated in the tubes. It was not possible to get any pressure
in the box ued for steaming this machine, and it i., very probable that
the temperature of the inside of the long ruhhbber tubes did not reach
that of the steam, and hence did not become sufficiently heated to kill
the bacteria in them.


A, stated at the beginning of this discussion, an attempt was made
tio determine the keeping (qualities of the milk by taking two subsam-
ples a, soon as the milk reached the laboratory and keeping one of
the.-e at a constant temperature of 70(- F. and tlhe other at 50 F.
During the day these samples were watched and the time at which
they curdled wa.s recorded. It was, of course, impossible to watch
the- samples during the night, so that in the case of many of them the
exact time of curdling could not be determined. Where the samples
curdled during thIe night the time of curdling was arbitrarily given
as midnight, and all such results are indicated in the table.
'The temperature of 70 F. was taken as representing fairly well the
ordinary room temperature during the warmni season, and that of 50
F. a-; representing the normal temperature of the refrigerator in the
The records of the time of curdling for the different samples are
given in the various tables. It is not always easy to determine why a
certain sample o milk should curdle when it does. In general, nor-
inal milk becomes sour and curdles in proportion to the number of
bacteria contained, but this relation is true only between wide limits.
Not, infrequently one sample containing twice the number of
bacteria contained by another will remain uncurdled the longer


Time. There are, therefore, marked irregularities when we attempt
to harmonize the keeping quality with thle germl content. However,
taking a series of samples containing a high germ content anid comnpalr-
ing with another .eries with a (comiparatively low germ content, it w ill
he found that there is an invier.-e relation exisHtini" Ibetween the' g'erm
content and the keeping tiquality. Frequently thi .ihecie of mlg'anisimis
which the milk contains, hal% iloit'" to do with determine ing it- keeping
qua lity than does the act t:al niiillier of bacteria which may b,' in the
milk. This fact. accotint.'for (maiy of the apparent discrepalneie-
between the germ content and the keeping quality. While the re-,iltI
given in thile preceding tablle,. .how ilanyl irreg'ularitie.", yet they are
of considerable interest, and inll the long Iii aie of ialue lie an indica-
tion of the keeping qiutality of the different ample. of milk.
In Table ar oT given the averages for the oeerm content arld ke eping
quality from the six preceding tahle.. While the,-e aM r;ig..c an' not
of as imuch value as the results of the individual experielint-,. they
give in a general way tlhe relation existing between the machin-e-drai u
and hand-drawn milk.
It will be noticed in this table that there is a difference in favor of
S the keeping quality of the machine-drawn milk, both in the .ampleu-
kept at 7"0 F. and in those fept at, 50- F.. the greater difference in
favor of the machine milk being shown in the sample. s wh ich %%ere
S kept at 50- F. One important fact which i.6 shown in this table- i, the
greatly increa.,ed keeping quality of the.i milk which wa, drawn into the
steam-sterilized machine marked "'A" in the tablo. These samples
held at 7O-' F. kept onl thle average one-third rllonger thian tlie aVei'rage
S of the ordinary machine-drawn or hand-drawn milk. while those held
!at 50' F. lad not curdled by August 1' when the tet ended. This
emphas-izep- the importance and indicate', thit p-;'.ibhilitie, of greatly
increasing the keeping' quality h% thoroly 'terili ing the machine.
TABLE 1.-.YS ,.mn la ,4 1l'if m oii tt'l l arl ktep;i'q ,rje'i d ,l" nle' ,,9 Irmd,, .%1,. I.

N ln "[,,l ~, e. errs' t~u
\~i 41I [tlln. |,' *[ .%[ h,, I~ll~ l I" 1,' illf :I I -->l l
r' 1 1 1 11 ." n I ''I H -- -
,l1-rlr. iiiiu "I I '* il I
ni n i 1 i. i'l T i.11 F'I-

i ....... .. .....I H, Il linj . 7 .v : ;,";.* I I I',I
............... . ..... ... i h r. .........2. I 'IA ,, I 7
Nho ha i nt-. . 3- 1 41 I- 7
1 li- d ......... 03 4- .:1 0'
1 j M i. h e .:.;... I j*'. i 72
i Hand .. ..... -'40, 154 32 l;'j
6. 2 1 M aehliihie ...... 2.5, -i6.' 1 U'J9
. ... ... . . ... . . 2 111 H n i ... ..... 4I 12 42 xti
I 7 1 M'n h ne ...... 3.% 3- .,
S. .. .. .. . . . . .. . . . . . . . . . . . .. .. . 7 1l I 1, ... . . 2 2 4, ;7: 3 -' 2'I
| i. MeelltheInL ..... J-),ee I-' "U 1
Sf .... .. .. .. . ... . ... . .. .. . . . . . i r A ..a 1 t1 r I '.'7 I i7 1
fi H nld ......... e'i i 41 'ij
a Nut curdled by Auguit I'.



The conditions of cleanliness existing in this stable are considerably
above the average gfig. 6.) From a sanitary standpoint this stable,
was not as well constructed as was the one at farm No. I. The stable
is entirely below ground on the west and north sides, but receives a
good supply of light from the south and east. The feeding alley and
mangers are made of cement, but the stable floor, the drop, and the
main floor behind the cows
are made of plank. While
D the construction of the sta-:
0 ble itself is not especially
S suited to the production of
clean milk, considerable
/) care was taken to keep the
0 stable and the cows as clean
JCk as possible. Considerably
o 0 more than average care was
\ exercised in the milking
0 and the subsequent han-
0 dling of the milk, so that
0 this stable may properly
represent a fairly sanitary
dairy. It is not to be ex
Fif. t1-Batria in atmosphere of barn at fTnirm No. 2. pected that the germ con-
[irawing from photograph tif gelatin plate exposed for tent of milk produced in
twenty seconds in stable at milking time, h',howing the lot such a stable could be kept
germ content of the atmosphere, colonies per plate.
as low as in a stable con-
structed on more approved sanitary plans, but the number of bacteria
found in the hand-drawn milk, as given in the following tables, shows,
however, that the sanitary conditions of the stable at milking time
were excellent. The .-table floor was always swept twenty minutes to
one-half hour before milking wa? commenced, and just before milking,
the udders were wiped with a damp cloth.
In beginning the experiments in this., dairy it was desirable, first, to
ascertain the relative germ content existing in the machine-drawn and
hand-drawn milk. For this purpose the herd was divided into two
lots of 4 cows each. One of these groups was milked by the machine
and the other Iy hand into an open pail in the ordinaimy way. As
soon as the milking was completed, samples were taken from the
mniixt milk of each group of cows and these were carried to the labor-
atory for teting. The details of these experiments are the same as
those already outlined in connection with the experiments at farm el


No. 1. In this series of test., samples were taken at the night milk-
ing only and were placed on ice until the next morning, when the plate
cultures were made. It is probable that the figure,. given in the tables
are slightly lower than would have been obtained bad the sampless
been plated immediately, since there is usually a dropping out of cer-
tain species during the first few lour-. after drawing thle milk. In a
few cases where the samples were plated at night and again the next
morning this was shown to he true.


At the outset it. was desired to a-certain the efficient;y of the milking
machine with the treatment it \%as regularly v receiving on the fa1rm.
Three days' tests were made without altering tlhe treatment which the
machines received and the results were comipared with those obtained
from the corresponding sample-s drawn by hand. Thie results of tbe.o
tests are given in Table il,.

TABLE 10.-Comwpari.son of rI. /If oti /I.arn d ea'? inma..n/ 'ir ,a/kanq-n '.h;,,e fdn.ied with
cold water, i'r .ftt i'ith uvr, t atc,' ,W'o .c ,,W, qi. ..,1 s1.4 :, /lia r, s, ,i th t i l1., iui., r.
11lr (in a ll '-
I1 H e L-'rias pi r i uiIi a. nrlza'r ..r (.1 nelf1 ir all a l i_ cI
I N Mun- I ofitf i
Date. b er of M1ithoidi ,.f r. i -, r eui
expart- milkiniz T,,L ir .. ri Per h .' nt 0,Iiui ev. -l. F -
m r" 1jl,|- 1 '01 Ingl Lo; 71"fF II" F.
roel'lt Lll, lerta.I bN clu itr=. bit, te-.I'l~. Jl e lI
meriR. Mill.

Jul% 21. t.9. 1.!0 1. .13 _2 1 1 :2 i
} "l ....*-* I H a n,] .2.. 4.. 2 i, L. . .. .. ..... .. :, ]' i ia l l
Jul)" 1. .5 Me hina e .... ,. 143 7.2, 2, 4011 17 7r, li'.
Ju,,,., IJ 9 Mi lshune. .. 4 .I taa1 Ji.i$ .1i0 I ;'J j 'ii i1 a *j7
July 23...... I-f Hend ... .I l .,7i : 26 L O 2 .,
P.: A ra BB ....... Ch L ll 1 tf .... 17 .''.4(1)~ H .* .... .. .. 1 41 j] 1 .. 117
S.J l. M.h e. I i i e . ... ..- .. .. .12 1 I
Averages Mi h ... 1.. 91 106 149. .......... .. ....1311. . '.3 124

During this period the machine- were treated as follows: After
milking they were rinsed by pumping roldi water thru them. This was
followed by warm water containing some washing powder, corn-
monly sal soda. They were then rinsed ,with clean hot water and hung
up in the air until needed for use at. the next milking. A glance at
the "Total bacteria" column in the table shows thle same relation exist-
ing between the bacteria found in the hand-drawn and machine-drawn
milk as was found in the experiments at farm No. 1. The number of
bacteria in the machine-drawn milk was decidedly higher than in tlhe
corresponding band-drawn milk in each experiment, tlhe average for
S the three samples of machine-drawn milk being 17"2,958 bacteria per
S cubic centimeter, while the average for the hand-drawn milk i 9),-410.
S It will also be seen that the organisms in the machine-drawn milk were
largely acid-producing species. This also correspond-, to the conditions



found at farmi No. 1. It is evident that the milk became contaminated
with large number, of acid-producing organisms while passing thru
the machine.,. These results seem to prove beyond question that the
care which the machines were regularly receiving was not sufficient to
keep the tubes in a sterile condition and they had therefore become
breeding place, for bacteria, which were washt into the milk when
the machines were used.


At this point a slight change was made in the method of treating
the machines, and the figures given in Table 11 show the results of two
days' tests with the machines thus treated.

TA BLE 11 .-Compars.nm it results of hand ud machine milking-treatment of machine the
same .s inrdiraled.lTor Table 10, except that ?t ra.q scalded just before use by pumping
boiling water thru it.

No. of
Dale. expert.

-,..... "' I
Juh 26 ..... 1
Average .. ..... ...
A\ 'erage .........

a U'dder- I

Baclerit per cubic centimeter of milk. iourS tocur-
Hu ling at-
Melhodo : . ~ ~ Pe e
milking Tctl 'Anilacii ,Percent Liquefy- Percent
i bTteria. tna. \i bid a lique- b 70l F. W50 F.
lgb y-iyng
batteriaeria teiia bacttria.
..... +,,,bac~teria.

Machine .... 22r., 700 A. &3 3 2.287 1 76 130
IHani ....... I l. 50o 2, 60') 22 2.50 2 b54 b 102
Mm hine ... I2.:,00 4.,988 42 487 4 97 171
Hand ....... 1,100 475 43 112 10 64 171
IMachine .... 119.3",1) t. .N0 ............ 1,387 ... ...... 7 151
I-lu nd ....... h,475 r ],.-37 .......... 181t -. 59 137

not washt. tCurdled at niehbi-exact time not determined. J

Thile machines were washt as previously described, but they were
given an additional scalding ju.-t before being used by pumping boil-
ing water thru them. It was hoped that this might dislodge and wash
out any bacteria which might have accumulated in the tubes during
the day, thus reducing the germn content of the milk. This additional
scalding, however, apparently had little effect upon the condition of
tile tubes, since the numbers of bacteria were not materially decreased,
as will be seen hy.a study of Table 11. Both the total number and
the number of acid-producing organisms and also the Hquefying bac-
teria continued to be much more numerous in the machine-drawn
milk than in that drawn byv hand.
It will be noted that in experiment 13 the udders were not wiped
with a damp cloth previous to milking. This fact, no doubt, at least
partially accounts for the high numbers of bacteria found in this lot
of milk.



.After being washt as previously described, the rubber tubes and
teat cups were placed in water and boiled for three-quarters- of ian
hour. They were then hung up) in the opl)en air until needed for the
next milking. Just before using they were rinsed a-, in th,- previous
experiments by having boiling water pumped thru them. Table 12
gives the results of four tests taken with the machines thu-4 treated.

TABLE 12.-Comoptarei.oin if results 1f ) and aind i ,i md/tilk intt --ifgv ie.; r; iwith
cold wider and wui.thl with d .oil,'oa, then boled foar lthrie-tu.rtl'tr- ofit n h itr andtl rntsd
with boilii; irater just'ire axe.

Bacte-ria I er utie i r In II t--r ll m l k H..l*ir, in cu r-
No. ulf Mho -
Date. expert i ToI."I r' 'iii
inlleeng. Total At a ld r i t nt L d ijeee1 b It 'iiy nc F
0 ii;d ba h, 7 -d'* -KI" b.
bat trla. bacteria bat terl.a t-ieria. lytfln

July27 i -29 Macrhine l1,7 37 3.,,2. ;' 1I'-' 4 91 74
S..... o Hann . . 1 125 10 13.7 i4 *' 12i ,rl'O
July, I2 35 Mai-hine ,.612 Sii 1 !Ul. 2 Mi ,I AI
3L....... b -Hand. ... 63, -37 4t,2 :iU 1 I I 2t)
July 29.. :3 Ma t nchmle e 0 ,2 y'U 97 1,;77i0 1:34
...... 10 Hand .... 7.17 75 1 2.2u0 1 Sb 87
July 30 M 17 MNIchine ....... . ."........ ... . ... .. 54 r.102
4.. Hd d ..... 3.U 3 tl ;t10 3 I liii 171
Av Mailne 36, 1'43 2%,; e . 1. 241 .. ... 91 91
Average ...... -1.... ... H n .. ....... %47 ....... 71 1,13

n C'ardLlcl ie nigli-iet'irE inL im !l ilntt-rri niti,.

This increased treatment of the imhlihine ili)parently wa. not .,utficient
to greatly change the quality iif thle nia-hinie-drawn inlil k. However,
in experiment 35 the i' nu lber of bacterial in the mniachiine-drawn niilk
was somewhat less than in the corresponding hand -drawn simple. It
should be boit ine in mini that thie niImlih'rs of bacter ia obtained IbY the
hand milking are extremely low for milk drawn into ain orilinarv open
pail. These low nuumber-' of bacteria found in the hand-drawn inilk
emphasize the fact that thle atluosphere in thle -table wa, relatively
free from organims, and that considerable care was exerci.-ed in thlie
drawing and handling of thie milk. The inan ii ho did te' milking wa,
unusual careful in all L Ilis operi'ations. In experiment 3! the ruIlbber
tube connecting the piilsiator with the .-tanclhion cock wa, not boiled
with the other tube-,. and it is l)rolbale that this furuni.hed tlie -ource
of contamination and exl)aiiin- the very liilh numllber of bacteria in thi,
lot of milk. In order to determine whether the rubber tulle- were
responsible for the larger numbers of bacteria in the mnachine-drawn
milk a new set of tub.- wa, u-ed inll expl)erinient I;3 and These
new tubes were washt and then .-.calded. together with the ret of the
machine, just before during. Thi re-ultedI in a smaller number 4f
L bacteria from the machihe-drawn milk than had been l)reviu.sly
I obtained.


TABLE 13.-Comparon oj res.,lls o"f hand and mnacine nilking-new tubes and teat
cup. u.sed, and mnctrhit's vishlt acr- usual and sralded before using.

I Bacteria per cubic centimeter of milk. Hours to CuT-
Num _______________dng at-
Dae berof Method of I | Per cent
ae. xperi milking. Total cid Percent uLiquefy-
___ ~ ~ ~ ~ ~ o l*__i qu.el^ 3 0- 500F
ment. bacteria. of acid ing bat lique- 700 F.
b t i I i f bacteria. I ,rea. bacteria.

A u. u . ..3 Nlachine.. 3 .325 162 4 I H7 2 _6 a 126
Au u. ...... Hand .. 650 275 12 '25 4 161 206
August 3. 69 Machine.. b 1t. F37 92.5 5.:3 1 50 116
. 70 Hand ..... 1,344 150 12 144 11 a 102 a 126
lJMachine 631 .4 .' .... 55 .......... 68 121'
A -frage-S..... ........ cin. I.3 455 2
.lrge ........... Hand .... i 7 212 ......... h 132 166

a Curdled at nigni--exact lime not determined. bTwo jets of foremilk removed,.

The results of these tests as shown in Table 13 would make a very
good showing for the machine were it not for the fact that the num-
bers in the hand-drawn milk were so extremely low. However, it
ought to hIe possible to obtain milk by means of the machine which
would contain a lower germ content than hand-drawn milk under the
same conditions provided the parts of the machine thru which the
milk past were sterile at the outset., since the milk drawn by means of
the machine is entirely shut off from external contamination. Itought
to be possible to obtain the milk in the pail with practically nothing
but the bacteria whi.h exit in the udder. This manifestly was not
the case with the trial., mniade thus far and it was evident that still
greater care was nece.,-,ary in order to completely sterilize the machines.
In order to determine the real condition of the inside of the tubes a
test was mainde at thil point to find out whether or not the inside of the
rubber tubes was beingsterilized by the treatment given them. Asmall
quantity of sterilized water was run into the central part of the long
rubber tubes and rinsed back and forth. This wa-_ then poured out
and a drop of this water inoculated into a gelatin plate. This resulted
in the development of 1,728 colonies of bacteria as the germ content
of a single drop of the water used for rinsing the tube. This showed
beyond a doubt that the inside of the tubes was not being properly
cleansed and sterilized by the treatment thus far used and that greater
care was necessary in order to overcome this trouble.


The writer desired especially to test the efficiency of the machine
for the production of sanitary milk, or milk containing a minimum :
germ content. It was therefore decided to take still more vigorous :
means, for cleansing and sterilizing the machines. To do this, in addi-
tion to the treatment usually given, the tubes were boiled for three-
quarters. of an hour in water containing a small quantity of powdered "
borax. They were then thoroly rinsed with boiling water to 71


remove any traces of borax which might be in the tube,. A small
amount of borax was also added to the water used for w iping off' the
udders. In addition to these precautions a small amount of foremilk
was also drawn before attaching the machine to the cow..,, and the pail
was carried out of the stable before the cover was removed. Thik
treatment proved to be more effective than any previously given. azis
will be seen by a study of Table 14.

TABLE 14.-Comparison of results of hndl nil inachline i;iilk'ing-nacih ies rinse iinti
cold water, mash it ilh warm w'al'r c 'mwia;niil sal sv.da, tt.ile, Ithree-qatrters of an thuir
in wnler wtf/i boroar, awid Lsalded jtn. be lUre fte; rtdilers ,riptd ,,'i th oru ai anler.
. . . .. .. . . . . lh ,..'r- t'' c. u r
; Bacteria per cubitL rntimetr oi milk dhn' at--
No. of Method of P
Dalte. e xpe r Metho ortri 1- Ii e rY i c1-1ert
meDale. milking. Totali Arid I de, FnL e ce
men.,e*,I"er'tt *d b ot fina e
bacteria ba ter, I bacteria F

Augut 1 .5 M chin.. 462 .. . .. .... ..
August .... 6 Hand ... I 1) 2-2. . ", ,4 139
A g s 5 1 Machine .IOU 12 3 27n f .'2-1:, 1,1
AUgUSt ..... 8, Hflnd .... SkI i] A u 1 g* ,.,.
August I | 7 6 MfLnhine tl2 1 I, 3; 6 t.;', 124
Augus Hand ... r. Ota 7.. w, u 4b luu
AverMgIe'h '")Ut) 12 .. .... 1 I ... .', 12
Averages ...! ...... i)Hand 1.., I.Uju N : ..... ... Hi .. ..... ...l-'0

a Nul curdled by Augist 19 h Curdled mat nighl--xait i time iili duitermined

It will be noticed in this table that the machine-drawn milk con-
tained in each case much smaller number., of bacteria than did the
corresponding hand-drawn milk. These numbers compare very favor-
ably. with the germ content of the best grade., of -anitar"" o,
"6 clinical" milk which are now placed Ul)On the market. In fact the,e
numbers are below the germ content if much of such milk. The
results of these te.,t- are sufficient to prove that the germni content of
milk can be reduced to a very low figure by the u-e of the machine
when properly sterilized. While the boiling in borax water \ias
apparently an effective treatment, attention s-hould be called to the
danger of using this or other anti.,eptics to rid the rubber tuie0, aind
teat cups of bacteria. A very thoro rinsing of the tube- is necessary
in order to remove all traces of thle antiseptic so that none of it van be
taken up by the milk as it pab-e-, thru the machine. If the antieptic
were left in the tubes it would be the same in effect a, treating the
milk with a preservative-a practise that is considered very objection-
able. There was also some question in regard to the effect of the
boiling upon the life of the rubber tubing, and it was some work to
boil the machines in this way each day. For these reasons it was
thought desirable to find a simpler way of sterilizing the machines and
one which would not have an injurious effect upon the rubber.




Common salt is a good germicide, and it also has a hardening and
"preservative effect upon the rubber. It was therefore thought that
possibly a brine .solution might be used for sterilizing the rubber tubes
instead of boiling them in borax water. To te.,t this the machines were
washt as usual, after which all the rubber parts were placed in a moder-
ately .strong brine solution, where they remained until needed for
the next milking. Before being used they were thoroly rinsed by
having boiling water pumped thru them. Table 15 gives the results
of the tests made with the machines thus treated.

T.ABLE 1.7). m/f.i'risoCii of results ot ha n'i and machine milking-machineR being washl as
01.uual, th'e ruhber parts then phlced in lhrine lillt needed, and scalded just before use.

Bacteria per cubic cenlimeierof milk. Hours to cur-
Sdling at-:
Date. expert il.ethoIe of Percent
mi lk ng. Tutal Acid Per cent Liquel of lique I
men bacteria. bactrid of acid ing ha.f hi 70' F. 500 .
acte ,bacteria., lerit, flying

.V, 9 I 3 MNm:hine.. f. 450 .175 10 52 100
S -14 Hailnd..... 4,0752 I 1 363 9 'M 54 a 102
A uz 99 ,9 l Machine.. 1e(0 112 "t 100 21 48 109
u0 H'O Haitd... 600 1O t16 0 0 68 121
Angii-I I fI.. Mrat hint.. 483 10J 21 at 7 101 (b)
1116i Hand..... ',,T, 34. o 7, 1.449 8 d78 t b)
.,jN1, IM hine *, 414 '*9 ..... 2S3 .......... 67 105
.......n. lHnd ..... 112,7 1.006 ........... .. I ......... 67 112

uiiril-. iln iiithi--xnct rime not del-rmrined b N,) curdledi Augusl 19.

It will be noticed that in experiment 93 the number of bacteria was
decidedly higher than in the preceding tests given in Tables 13 and 14,
while in experiments 99 and 105 they were as low as when the machine
was treated with borax. Probably the higher number in experiment
93 wa., due to the fact that only part of the rubber tubes were treated
with the brine solution, while on other days all the rubber parts were
placed in the brine. It would seem from the results of these tests
that the brine treatment is a., effective as the boiling in borax water
and is at the same time much simpler.


The usual method for sterilizing dairy utensils is by steam. This is
entirely satifactorv with ordinary dairy utensils, but steam is known '
to have an injurious effect upon rubber, for which reason .steam ster-
ilizing evas not generally used in this series of experiments: but at this
point it wzl- deemed desirable to compare the efficiency of steam ster-
ilizino with the treatments previously given, in order to determine
whether oirl not it was possible to reduce still further the germ content ..
of the machine-drawn milk. To accomplish this a large wooden box


was fitted utip to serve as a steam sterilizer. After the machine had
been washt as usual, it was placed in this box iand subjected to live
steam for 30 minutes. Table 16 gives thle results of this seriess of .tJests.

TaBLR t16.-Comp/arieoI of resslt.- eaf lihindi aund mitchii ig-mirh .i, i;aht is
iFsii4I aid .sft ii:'. d il s:amn lor Ihirliy ini ters.


lieril pcr culc. ( .[1]n[i.,,er (iI milk.

mbe i i l MiLnodc Pf iper cent
Date expert milking a Per cent Liu'ue.,y o li.e.
mex erAv of ae ld I II_'. flyng
bin ler'a. bacteria. bacteria bact ni. bafrer

III Ma(hine. '60 37 7 0 .......
usl If- .. .' 11]2 Iind.... 10 11i2 22$ 75 19
I ? 117 Marhine. 1.962 337 1,1' 7i 4
us 118 Hand..... I, 762 37l 2" 2s7 17
1. 12.] Marhine.. 1.067 137 14 ; A, 7
ust 12 ...... 124 Hand ..... .o 1 1011 12 112 13
u 13 ..... 129 Machine.. 9.8,7 2,2 17.4
u t 130 Hand ..... 5, li,' F.I 1U 2,,j
s 14 ... I 13, Machine. 3.7.0 3'7 1U 162 4
ust 14. I 136 Hand.....' 1,337" 362 2_ 271 21

A>% r e .IMa hine. 3.449 22: ........... 137 .
A ernge. ........ (Hand ..... 1.97, 162 . ..... 20 ....... ..

I loulJr to c'i'r-
Ming l-

70- F. i

bi F.

77 i'nl
1p "Ia)
t.9 i' i
S.30 60
49 rt
4*1 p 'ip

A~ f l
''"I ILr)
1 54 ,

1,4 . ....
7"9 ... ...

Nol curdledi A1ugirl 19.

l''iirdled ati nighlt-exa.'ct iimi no1 a-t.rn'anr l

It will be noticed that in each tet the machine-drawn milk contitined
larger numbers of bacteria than did the corresponding hand-drawn
sample. It was impossible, with the equipment IIse.ed, to get any
pressure in the steamni chest, hence the temperature did not quite reach
the boiling point (212: F. Under these conditions it is probable
that the inside of the rubber tube. did not I)ecome heated to the tem-
perature of the steam, and they, therefore, were not sterilized during
the thirty minutes, that they were subjected to the steam treatment.
Probably a longer .-teaming might prove effective, lut it i- evident
that the treatment here given was. not stiufficient to completely -terilize
the tubes. The rubber tubing did not apl)pear to be seriously injured
Sby the steam treatment during this series oif tests. liut it is quite prob-
able that long-continued steam sterilizing would injure the rubber.
This series of tests would at least indicate that it is necessary to sub-
ject the tubes'to greater steam pressure or el.- use other germicides
in order to completely sterilize the rubber tubing. At the close of
this period one test was made by treating the machine in Ibrine, as
already described. The results of thi,, test are shown in Table 17.

I TABLE 17.-Comnp rituir uo of results fhanld ,, iii, rh 'liit in i;n'q-i-.irhilii't hirratil as l,,I;-
,r caeh' fur TUble 1.5.

ber of Method ol
experi milking.

AtigU. 15b. Il Machine .
Agust .... 142 Hand.....

Bacleria per cubic cenlumeler of milk.

HiIur lo I c r-I
l1nmp at-

Total ;d Per Liuef. PU recent
W A1f lique.
batleria. barierin. at u 111 bee- i ine 70-1 F .0 F.
bhri., ,la rter .

13.67.5 2.463 IS 1,"51: '
2.100 763 36 491 3 ........





The discussion of the keeping qualities of the milk given in con- :.
nection with the experiments at farm No. 1 will in general apply
with equal force to the results obtained at farm No. 2. Practically
the same results were obtained in both cases. In the majority of
ins.,tances thle difference in keeping quality is in favor of the machine-
drawn milk, both at 70-' and 50- F. This difference is especially
noticeable in Table 14, where the germ content of the machine-drawn j
milk averaged the smallest. With an average of 506 bacteria per cubic
centimeter the milk kept on an average eighty-eight hours at 70 F.,
while the hand-drawn milk, with an average of 1,090 bacteria, kept an
average of but fifty hours, making an average difference of thirty-eight
hoir-, in favor of the machine-drawn milk. This, at least, is an indi-
cation of the extent to which the keeping quality of the milk may be
improved by the use of the machines, provided they are kept in a
sterile condition and care is used in their manipulation.


Tihe results of the foregoing experiments seem to justify the follow-
ing conclusions:
1. Unless sufficient care is used in cleaning the machines, decaying A
milk and bacteria accumulate in the rubber tubes and contaminate the
milk as it passes thru them.
2. The few dairymen now using these machines are not exercising
sufficient care in washing and sterilizing the machines to keep them in
Ianitarv condition: their milk is therefore of poorer quality from the
-anitarv standpoint than that drawn by hand under the same stable
3. (Good sanitary conditions in a stable may be completely counter-
acted by the insanitary condition of the milking machine.
4. When kept in fairly clean condition the machine-drawn milk
contains decidedly smaller numbers of bacteria than the corresponding
hand-drawn milk.
5. When thle machines are not well cleaned both the number and
percentage of acid-producing bacteria are higher than in the hand-
drawn milk, but when they are fairly well cleaned both the total num-
ber and the percentage of these bacteria are decidedly lower than in the
corresponding hand--drawn milk.
(. Both the total number and the percentage of liquefying bacteria
found in the milk were in most cases greatly reduced by the use of the
machines. This fact is of special significance in milk designed for
direct consumption.
7. When properly cared for, drawing the milk by means of the
machine increases its keeping quality.


8. Washing the machines with cold water and then with hot water
containing sal soda is not sufficient to keep the rubber tubes clean.
Under this treatment the inside of the tubes becomes coated with decay-
ing milk, thus forming ideal conditions., for the multiplication of
various species of bacteria.
4. Scalding the machines by pumping boiling water thru them just
before use had little or no effect in reducing germ content of the milk.
10. Boiling in clear water for three-quarteri of an hour was not suf-
Sficient to keep the rubber tube, in a sterile condition.
11. Subjection to steam without pressure for thirty minutes was not
sufficient to sterilize the rubber tubes.
12. Placing the rubber parts in brine for -everal hours after being
washt reduced the germ content of the inchine-drawn milk to about
one-half that of the milk drawn 1 hand.
13. Boiling in water containing ia .mall amount of powdered borax
had about the same effect in reducing the bacterial content of the milk
as (lid the brine treatment, l]'ut the u-e of Iborax is dalngrrous unless
extreme care is exercised.
14. The machines, nmay be very effective in the production of sani-
tary milk if they are properly cleaned and ,terilized.
15. The results of these experiments indicate that the machines may
be kept in such an insanitary condition that the keeping quality will
not be improved, but may be seriouslyy impaired. They also indicate
that with properly cleaned and sterilized m'chine,- the keeping quality
of the milk may be very materially improved.


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