Sf FPLORIDA AGRICULTURAL EXPERIMENT STATIONS
Dairy Science Mimeo Report 63-4
August 30, 1962
KEEP YOUR MILKING EQUIPMENT WORKING
J. M. Wing and J. P. Boggs*
The milking equipment works more hours annually than any other
farm machine. It's the only farm implement used twice every day of
the year. More labor is used in milking than in all other dairy
farm operations, yet the milking machine is about the least under-
stood and most often neglected piece of farm equipment.
All milking machines operate by vacuum. This applies to those
employing either pails or pipelines. The vacuum on the teats is
continuous, it's strong, too, and would cause severe damage but for
the massaging action of the inflations (teat cup liners). They work
in the following manner. Continuous vacuum on the inside of the
inflation causes it to collapse. Periodically the pulsator applies
vacuum between the inflation and the teat cup. It is during this
interval that most of the milk flows since the inflation snaps back
to its normal shape. The alternate collapse and recovery of the
liner massages the teats, achieving the same stimulation to blood
and lymph circulation as nursing by a calf or the pressure exerted
by a good hand-milker.
The manufacturers of milking systems and allied equipm
easily understood instructions for the care, repair and o tion
of their products. These should be followed closely, but ddlionali
information also is likely to be helpful. The following ch ck ist
*Associate Dairy Husbandman and Dairy Research Unit Superintendent,
Department of Dairy Science, University of Florida, Gainesville.
can be used to locate trouble without an unduly long interruption.
It should apply equally well to pipeline and pail-type milkers.
A. If the machines have to be left on the cows for an average of
more than 3-1/2 minutes, it's likely there is a malfunction.
1. The inflation may be broken. This defect usually announces
itself with a persistent hissing noise.
2. One or more of the inflations may be worn or stretched.
This likewise can cause a hissing noise and may irritate the teats.
Useful life of rubber teat cup liners can be extended many times by
keeping two sets and alternating them at weekly intervals. Inflations
not in use may be reconditioned in two different ways. (a) They may
be stored dry in a refrigerator. The cold appears to restore elasticity
to the rubber, shortening the inflation considerably. (b) They may
be stored in a concentrated solution of lye. This will insure removal
of any fatty particles, and often will do more to restore the condition
of the rubber than will dry storage. One must have soft water for
this type of operation, otherwise the lye is likely to cause a
mineral scum which is very difficult to remove. Plastic-lined metal
pails or plastic containers can be used as storage units but the lye
must not be mixed in these vessels because the heat of solution often
is enough to melt plastic.
3. The vacuum supply may be inadequate. (a) If the slow
milking occurs mainly at the greatest distance from the vacuum pump,
the lines may be too small. It appears that lines in many older barns
should be replaced with larger ones and/or additional vacuum controllers
may be needed. (b) The vacuum pump may be too small for the operation,
particularly if the number of machines has been increased since the
original installation. (c) The belt between the motor and the vacuum
pump could be slipping due to wear or improper adjustment. (d) The
oil in the vacuum pump may be too low. (e) The vacuum line possibly
has a leak. (f) Air hoses or operating covers may be leaky. (g)
Vacuum lines or hoses could be plugged. They should be cleaned
thoroughly at least once each week, even though nothing but air sup-
posedly goes through them. On machines having adjustable pulsators,
it is possible that the pulsation is too fast. For the other type
machines, the pulsation rate is likely to be correct as long as
unusual electrical malfunctions have not occurred.
B. At times the machine milks faster at some of the teat cups
than at others. This may be caused by (1) leaking or stretched in-
flations; (2) the teat cups may be improperly attached; (3) the air
hose may be leaking; (4) the pulsator may be worn, or (5) the animal
may have malformed or injured teats.
C. If undue irritation to the udder or frequent mastitis occurs,
the following should be checked:
1. The machine may be left on too long. Any time the teat
cups creep upward they are likely to rub tender tissues of the udder
together causing injured teats and possibly more serious complications.
2. Machine may have been removed without breaking the vacuum.
To release the vacuum the udder should be pushed in just above the
teat cup, allowing air to enter the system.
3. The pulsator may be too slow,
4. The pulsator may have stopped due to failure of the
mercury switches on equipment employing this type of control.
5. The pulsators may have been damaged or worn.
6. The pulsators may be blocked by dirt or other foreign
7. The vacuum may be too high.
8. The vacuum regulator may be stuck or improperly adjusted.
It should be inspected and cleaned at regular intervals.
9. The entire system should be checked periodically, twice
a year if possible, by a factory-trained representative with special
10. The pump speed may be too fast due to improper pulleys or
a malfunction in the electrical service.
D. Excessive bacterial counts. Special attention after each
milking must be given to spots which brushes are likely to miss.
Square corners are disappearing from modern dairy equipment but to
the extent that they still exist, these spots must be inspected
with special care since they are particularly difficult to clean.
Another frequently missed hiding place for bacteria is just under
the flange of the inflations.
Milking machine operators are food handlers. They must be
sanitation-conscious and keep in mind the following points:
1. All equipment must be washed as soon after use as possible.
2. Use a cold water rinse first to remove material which would
be cooked onto the surface by hot water, thus starting a milkstone
3. Then wash with hot water, a good detergent, and plenty of
4. Sanitize washed utensils with an approved bacterial inhibitor,
Most of the usual dairy sanitizing materials can be used to wash the
udders, and to rinse the teat cups between cows. Dip and wash
solutions must be changed often, however, or they do more harm than
good. Quarternary ammonium compounds and tamed iodine solutions are
increasing in popularity for use during milking. This is partly
because chlorine is likely to be irritating to the udders and the
milkers' hands, and to be harmful to the wash cloths. Another point
is that the effect of chlorine solutions is inhibited somewhat by
the presence of organic matter. Chlorine continues to be a favorite
for use on equipment.
No job on the dairy is more important than milking and nothing
gives more satisfaction than properly harvesting and handling Nature's
most nearly perfect food.