Teat disinfection is the cornerstone of all mastitis control
programmes. Disinfecting the teats after milking (post-milking teat
dipping / spraying) is one of the key planks of the 5-point plan
introduced in the 1960s and, since then, has been shown to be
effective in a huge number of studies. Pre-milking disinfection has
not been in use for so long, but is now commonly seen
There are two commonly used methods of teat disinfection -
either dipping each teat separately using a cup filled with
disinfectant or by spraying disinfectant onto the teats from
below. Whichever method is used, the full benefit of teat
disinfection will only be achieved if the disinfectant is applied
efficiently and effectively. The two main factors inhibiting
the effectiveness of teat disinfection are ineffective formulation
and poor application. Problems with product formulation are usually
due to either incorrect mixing of concentrate on farm, or to
extraneous water getting into a previously prepared mixture. Poor
application, i.e. failure to cover the whole teat of every cow at
every milking is the most common error in teat disinfection. All
the benefits of correct product selection, preparation and handling
are lost if the teat disinfectant does not reach the skin of
the teat. Proper disinfection is not just disinfecting the teat end
but disinfecting the entire teat barrel - that is, everywhere the
liner has touched. However, there is no benefit to be gained in
disinfecting any other part of the udder surface. Teat
dipping is the best method of disinfection, but spraying can be
just as effective, if it is carried out conscientiously.
Fig 1: Teat dipping
Fig 2: Teat spraying
Pre-milking teat disinfection - what's the
Pre-milking teat disinfection involves applying a quick-acting
disinfectant just before milking to reduce the population of
mastitis-causing bacteria on teat skin especially in the region of
the external teat orifice. The major effect of pre-milking teat
disinfection is therefore against those environmental
micro-organisms which cause mastitis. Pre-milking disinfection is
not aimed at improving teat condition, so the addition of an
emollient is not indicated.
Pre-dipping reduces new environmental streptococcal infections
and Escherichia coli by as much as 50%. Pre-dipping teats
should be considered if there are high numbers of mastitis cases
due to environmental bacteria (> 5 per 100 cows per month), or,
particularly in spring-calving cows, at high risk periods such as
in the first week after calving.
Pre-dip should be applied to teats after they have been
fore-milked and then dry-wiped, or washed and dried. Pre-dip needs
a minimum contact time of 30 seconds and must be wiped off prior to
the application of the milking units. If you are going to pre-dip,
ensure that you use a registered product and do not just use your
post-milking teat disinfectant. Most post-dips do not have a very
rapid speed of action and their use as a pre-dip may contaminate
Post-milking teat disinfection - crucial for mastitis
Post-milking teat disinfection should prevent mastitis and
enhance teat skin condition. -In preventing mastitis, the
post-milking teat disinfection works by the removal of
mastitis-causing bacteria from the teat skin and teat sores.
Disinfectant should be applied as soon as the cluster is removed,
-while the teat canal is still open. The dip can then penetrate the
teat orifice, ensuring that those bacteria which have just entered
the canal will also be killed.
The main source of mastitis bacteria on the skin of the teat is
the milk from cows with infected quarters. Staph aureus or
Strep agalactiae from the milk of an infected cow can
remain on the teat cup liners for up to 9 milkings. This means that
infection can spread from one cow to the next 9 using the same
cluster. Most of the bacteria will be on the teat skin from where
they can move into the udder at the next milking. Unless they are
removed, bacteria on the skin can multiply (especially at sites of
teat lesions) increasing the risk of infection via the teat canal
at the next milking. Post-milking teat disinfection, dipping or
spraying, removes the bacteria that spread during milking and, as
such, is an extremely effective weapon against the spread of
Any skin lesion which is infected heals very slowly. Teat
disinfection removes bacteria from the skin surface, thus promoting
healing. Rough or chapped teat skin can also be a reservoir for
mastitis-causing bacteria, so thorough disinfection of the whole
teat is important.
Fig 3: Automatic teat sprayer
Dips can be applied by hand-held cups or with a 'power dipper'
(a dip cup on a wand with solution applied when a trigger is
activated). Dipping uses less product than spraying (approximately
10 ml per cow per milking versus 15 ml, respectively) and, provided
that it is carried out correctly, can provide an excellent teat
coverage. This application method requires slightly more time than
most spraying applications when taking preparation, refilling and
actual application into account. Cups should be emptied before
refilling, rather than 'topped up' when the solution becomes low
and any solution remaining at the end of milking should be
discarded. The cup should be large enough to
accommodate the teat without causing excessive spillage of the
disinfectant solution. The act of immersing each teat in a
reservoir of disinfectant usually ensures the entire teat barrel
(any area in contact with the teat liner) will be covered, as long
as the cup is deep enough and filled with the appropriate amount of
an effective solution.
Fig4: Teat spraying - checking the coverage of teats using
Spraying requires more disinfectant than dipping to achieve the
same degree of teat cover because spray will also be applied to the
udder. Sprays can be applied using a gun-type hand piece with a
spray nozzle or a fully automated spray system. Teats should be
sprayed from below using a circular motion to cover all sides of
all teats. The drawback of spraying is that there is a much greater
chance of achieving only partial teat cover than when dipping. The
absence of disinfectant on the other side of the teat could allow
the establishment of a reservoir of mastitis-causing bacteria.
Partly blocked spray nozzles can also result in poor teat
Fully-automated teat disinfectant spray delivery systems are
available. Infrared light beams activate spray nozzles and spray
patterns are adjusted to the average cow's udder. Although they can
save time and man-power, most automatic units will not give as
consistent teat coverage as manual spraying.
Teat disinfection products
More than 10 different active ingredients have been used in teat
disinfectants throughout the world over the past 30 years. The most
commonly used active ingredients are: iodine, chlorhexidine,
quaternary ammonium compounds, hydrolysed fatty acids,
hypochlorite, and acid anionic compounds.
Teat skin has relatively few sebaceous glands and continual
washing followed by exposure of damp teats to a cold and windy
environment can remove protective fatty acids and lead to cracking.
Hence, emollients are added to the disinfectant preparations. The
addition of emollients, such as glycerine, sorbitol, lanolin or
propylene glycol, to teat disinfectant can improve teat skin health
and so reduce the likely reservoir of mastitis bacteria in teat
sores and cracks. Many teat disinfectants contain emollients when
they are sold. Addition of excessive amounts of any emollient (i.e.
>20%) will most probably reduce killing activity and could lead
to increases in the new mastitis.
Fig 5: Dirty teat disinfecting equipment will
For effective teat disinfection always:
1. Read the label and follow the instructions on dilution rates,
water quality requirements, mixing procedures, shelf life,
compatibility information, and storage conditions.
2.Prepare fresh disinfectant for use (not older than 3 days),
and this should be stored in a container with a lid so that
extraneous water will not find its way into the already prepared
solution thus diluting it.
3. Regularly clean the equipment (minimum once a week).
Poorly prepared disinfectant applied with dirty and contaminated
equipment can be a source of new mastitis infections.