Dairy

DON’T TAKE YOUR EYE OFF HYGIENE
DURING THE SUMMER MONTHS
Just because the cows are out, it doesn’t mean that shortcuts can be taken with dairy hygiene routines. According to
Adrian Morgan from Wynnstay, there are plenty of sensible reasons to keep hygiene high on the agenda.
While cows might look contented when out at grass
and appear considerably cleaner than when housed,
they are still exposed to similar risks of bacterial
infection. It is all too easy to lapse into a false sense of
security, assuming cows are cleaner when in reality full
hygiene procedures should be maintained. Every year
we see a significant number of problems associated
with high bactoscans and rising cell counts during the
summer, most of which could have been prevented if
full hygiene programmes had been continued.
A herd cell count problem will not simply go away
just because the cows are out at grass. The infection is
within the udder. To keep on top of existing infections
it is essential to follow the proven five-point mastitis
programme and maintain effective hygiene practises
in the parlour.
Never assume teats are clean. Cows lying down on
a field of fresh grass may look a natural and clean
sight but they will still be exposing the udder to dirt
and bacteria. This is particularly true after a wet spell.
Scrupulous udder hygiene must be maintained and
nothing should be taken for granted. Use a premilking
biocidal preparation to ensure the removal of
bacteria from the teats before the unit is applied and
increase the attention given to teat preparation in wet
weather. Teat skin and teat ends must be clean and
dry before unit attachment.
Post milking teat disinfection is another area where
attention to detail will pay dividends. While it may
be tempting to swap to a summer product the instant
the cows are out at grass, it is sensible to carry on
with the winter product for a time until cows are fully
out. Maintaining healthy teat skin, rather than relying
on a fire fighting approach with creams and salves is
paramount.
Pay attention to cubicles and loose yards. Many
farmers will keep cows in at night initially. It is
important however that just because the cows are
only housed part of the day, it does not mean cutting
back on housing hygiene. Keep bedding fresh,
passageways clean and beds disinfected to minimise
the threat of bacteria.
Once the cows are out day and night take the
opportunity to clean and disinfect the buildings. The
sooner housing is mucked out and cleaned the better,
as by doing so it removes areas where flies and vermin
can live and breed and exposes parts of the building
that requires repair and attention before restocking.
And once the buildings have been cleaned, prevent
cows from having access to them.
Finally, take the time to review any hygiene problems
you had during the winter, such as high bactoscans or
peaks in the number of clinical mastitis cases. If you
can identify the reasons for the problems you can take
steps over the summer to prevent them reoccurring
next winter.
Low bactoscans don’t necessarily
mean clean milk
The production of quality raw milk is under scrutiny yet again as more focus is
being placed on producing milk with low Thermoduric levels.
Thermoduric bacteria are increasingly becoming an issue in raw milk supplies and
if they are not removed at the end of milking by an effective cleaning routine they
will stay in the plant to multiply in large numbers and be swept away into the bulk
tank at the next milking.
Thermoduric are organisms which have developed mechanisms to resist heat
treatment and can survive in small numbers during milk processing to become
spoilage organisms in finished products such as cheese, yogurt and fresh milk.
Although Thermoduric bacteria may not be of particular concern to the dairy
farmer, their presence can have an influence on the Bactoscan results if present
in large enough numbers and therefore should not be dismissed simply as a
processing issue.
In raw milk, Thermoduric organisms originate from sources in the cows environment
such as soil, fodder, silage, dust and the cows coat. These organisms can grow
readily on poorly cleaned and sanitised milking equipment.
• High levels above 500cfu/ml are a good indicator of poor milking plant or bulk
tank cleaning. Common faults with cleaning are:
• Inadequate volumes of water at each stage of the wash
• Poor water temperatures and profiles during the hot wash
• Poor choice or under dosing of chemical
• Poor flow and turbulence of water (mechanical action)
• Failure to include a terminal disinfection in the final rinse
• Inadequate milk stone removal treatment particularly in hard water areas
Parlour hygiene should not be thought of as a standalone task, but as part of
a total hygiene management system encompassing pre-milking hygiene, udder
hygiene and bulk tank cleaning as well as cleaning the parlour itself. It is only by
operating a managed system that optimum hygiene can be achieved across the
milking process.
With this in mind it should be remembered that it is also possible and should not
be overlooked, that some Thermoduric organisms can be derived from the cows
teats and gain access to the raw milk supply through inadequate teat preparation.
The use of a pre-milking teat disinfectant to reduce bacteria on the teat skin
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www.wynnstay.co.uk
followed by thorough removal with individual paper towels or cloths will produce
the best and most consistent results.
Where high Bactoscan issues are being experienced it is worth considering a bulk
tank bacteriology sample which will highlight organisms of concern and potential
solutions, depending on the numbers and combinations of bacterial groups found.
An effective routine depends on four factors – chemical choice and concentration,
temperature, time and the physical action of the water. These factors work in
combination with one another and if any of them are compromised then the
routine will not be fully effective.
Modern dairy chemicals are designed to work at a specific concentration. Reducing
this concentration by over-diluting the chemical means that there is less active
ingredient in circulation and this will reduce the effectiveness of bacterial kill and
deposit removal.
Reducing the time the chemical circulates will have the same effect, as the total
exposure of the plant to the chemical is reduced. But leaving chemicals circulating
too long is also a problem.
Temperature is an essential element in the effective melting of fat deposits and
the removal of Thermoduric bacteria that could otherwise survive heat treatment.
The aim should be to circulate the chemicals at a temperature of at least 65°C for
3 minutes.
While it is tempting to leave the circulation cleaning running while other jobs are
carried out there is a real risk that it will be left running too long and that water
temperature will drop too low to maintain the suspension of deposits in solution,
thus re-depositing them back into the parlour.
The final key element in an effective cleaning routine is water turbulence. The
swirling action of the water plays a critical role in the removal of deposits,
especially in the claw and milk meters.
With the current focus on maximising milk bonuses and controlling costs, the time
spent reviewing the effectiveness of the parlour cleaning routine can be time well
spent as it could increase milk price and save money.
Adrian Morgan
Dairy Business Development Manager
M: 07780 683043
adrian.morgan@wynnstay.co.uk