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Getting the most out of calving

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					Getting the best mastitis control at calving
The period around calving (from two weeks before calving until two weeks after
calving) is often the highest risk period for mastitis infections to occur. Therefore this
period can be critical in determining the infection status of both the individual cow
and the herd for the rest of the lactation.

Milk quality for the whole season (or lactation) may depend on the success of mastitis
control at calving.

Thus there are huge potential gains for farmers by preventing new infections in the
calving period. Many of these infections can be prevented by implementing some
relatively simple management changes.

These management changes have proven to be very effective on many farms – and the
real positive is that many of the changes cost very little or nothing at all! What is
commonly required is a little thought about how best to achieve the desired outcome.

Evidence from around the country is showing that Strep uberis is rapidly becoming
one of the most common, if not the most common, mastitis infection, and it is almost
certainly the most common infection around calving, so this month‟s theme and the
grabs have particular relevance to herds wanting to control Strep uberis mastitis.




Key messages

      Mastitis in fresh cows is costly and frustrating
      Cows are at high risk of mastitis during the period from approximately two
       weeks before calving until two weeks after calving
      Strep uberis is a common infection at calving
      Cows are more susceptible to mastitis if they have swollen teats or drip milk
       before calving
      Flushing of the udder shortly after calving will help to remove bacteria from
       the udder before infection establishes.
      The risk of mastitis can be markedly reduced by a comprehensive plan of
       management for the calving cows
      These management changes often cost very little or nothing at all
      There is a huge potential gain from preventing Strep uberis infection at
       calving
      Calving areas should be chosen and managed to keep them clean and dry
      Special care in the milking of fresh cows and examining the environment
       around the dairy could be part of a small investment that can give large returns
      Early detection and treatment of clinical cases increases the chance of cure and
       decreases the chance of spread
Grabs

      How can I get a clean dry calving area?
      How soon should I bring fresh cows into the shed?
      What should I do with springing cows that are dripping milk?
      Minimise the risk of contamination at milking
      Early detection of clinical cases pays off




How can I get a clean dry calving area?

“If you have to look where you are putting your feet to avoid walking on cow pats,
it’s too dirty for calving.”

Given that environmental bacteria (especially Strep uberis) are usually the most
common mastitis infections around calving, the ideal place for cows to calve is a
clean, sheltered, dry area, with very little faecal contamination. This can often be
difficult to achieve on Australian dairy farms.

The choice of calving area is further complicated by the need to choose a calving
paddock or calving pad where the cows can be easily supervised.

The best option for mastitis control is a clean grassed area with no surface water, but
it is often the most difficult to achieve, and has the added risk of potentially increasing
the incidence of metabolic diseases such as milk fever – it is important to have other
milk fever prevention strategies in place for cows that are calving in paddocks on
grass.

The ideal calving paddock should have a good cover of grass, and not have been
irrigated or contaminated with milking shed or feed pad effluent. This can continue to
provide a clean environment if the paddock is large enough so that grass cover is
maintained and faecal contamination is minimal. However, it is common for small
areas, which perhaps provide shelter, to become overused and boggy – and wherever
cows gather, so does their faecal output!

The only practical solution is to fence off such areas until they regenerate. If electric
fences are shifted across a paddock at regular intervals, clean areas can be provided
for new batches of calving cows. It is important to avoid „back-grazing‟ (where cows
have access to recently contaminated areas in addition to their new area). Some
planning is needed to create access lanes and allow for access to drinking water in
each strip-grazing area.

Calving pads can be a successful alternative for wet conditions. Drainage is probably
the most important factor and can be supplied by providing sufficient fall on the pad,
or by installing underground slotted PVC pipe drainage. However, many calving pads,
especially those with poor drainage, quickly build up high levels of contamination and
mastitis becomes a problem.

If this is likely to be the case, then options include either limiting the number of cows
on the pad, or limiting their time on the pad by only using the pad strategically during
very wet periods.

A practical guide for assessing how clean and dry an area for calving is that no more
than two pats of manure are present per square metre and no water is visible in foot
prints.

Faecal contamination from cow manure is the most common source of Strep uberis
infection, so avoiding a build up of contamination can be critical in preventing
infection.

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Caption
How soon should I bring fresh cows into the shed?

“If she calves this morning, she’s in the dairy tonight.”

When considering how quickly freshly calved cows should be brought into the dairy
to be milked, remember that there is an opportunity to flush invading bacteria,
especially Strep uberis, from the udder before infection actually establishes. So the
sooner the udder is completely milked out, the better the chance of flushing bacteria
from the udder.

A freshly born calf on a dairy cow is rarely capable of completely emptying the udder
at a single drink, and often tends to drink preferentially from selected quarters. It is
also possible for the calf to spread bacteria from one quarter to another as it moves
from teat to teat whilst suckling.

So, for the best mastitis control, fresh cows should come into the dairy and be milked
as soon as practical. Whilst some compromises may need to be made to fit in with the
farm routine, and also to ensure that new calves get colostrum, try to ensure that
wherever possible fresh cows are in the dairy by 12 hours after calving, but definitely
within 24 hours of calving.

It is important that once in the dairy, cows are completely milked out to achieve the
flushing effect. This means that the practice of only partially milking fresh cows for
the prevention of milk fever should be avoided, so other methods of milk fever
control should be in place.

If fresh cows in the shed are not letting their milk down properly, they won‟t be
flushing their udder properly, so speak to your vet about using oxytocin injections to
assist milk let-down and emptying of the udder.

If udder oedema (flag) is a problem and is preventing complete milk-out, then the use
of oxytocin may be assisted by other treatments such as diuretics and anti-
inflammatory drugs. Speak to your vet about the best options for you.

Many farmers have found that these subtle changes to their routine for freshly calved
cows have not only improved mastitis control, but have actually made the routine
easier – and the cost is generally nothing!

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Caption
What should I do with springing cows that are dripping milk?

“If she’s dripping milk, she’s in the dairy”

If a springing cow that is approaching calving has milk dripping from one or more
teats, it means that the protective teat plug from the dry period has gone from those
leaking teats - and if milk can leak out, bacteria can get in! This is often likely to be
worse in cows with large springing udders and cows that have developed udder
oedema (flag).

Once the protective teat plug has gone, and the udder is not being flushed by milking,
the potential for infection of the quarter is massively increased. You could think of it
as the front door being left wide open without anybody guarding it! It doesn‟t mean
that you will be burgled, but the odds are much greater that you will!

These dripping cows are at high risk (especially for Strep uberis infection) while they
remain in the calving area, but the choice of the most suitable management and
treatment options will be influenced by many factors, including the risk of metabolic
diseases such as milk fever.

The options for these cows include bringing them into the dairy and milking them,
and also induction of calving (especially if they are not right on the point of calving).
For those cows with udder oedema (flag), there are various other treatment options
available.

If you are experiencing these problems, or you think you are likely to, contact your
vet to discuss the various treatment options and how they apply to your herd, and then
consider how the management options will fit into your system.

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Minimise the risk of contamination at milking

“If the teats are left open or damaged by milking, the bugs can get in.”

Once freshly calved cows are in the dairy and being milked, there are still a number of
factors that influence their risk of mastitis infection. Freshly calved cows often have
teats that are swollen and oedematous. There is good evidence to show that these
teats have an increased risk of infection - this means that the first calving heifers are
often likely to be especially at risk.

This risk can be made much worse if the teat ends are actually damaged by the
milking process, or if the teat orifice remains “open” for a period after milking – so
the health of the teats relies on the milking machines operating well and being used
correctly.

Firstly, ensure the teatcup liners are in good condition and that they are not nearing
the end of their effective life (2500 cow milkings for rubber liners). Modern liners do
not need “breaking in” before use on fresh cows or heifers - the liners must be at their
most effective for massage of the teats. Liners also develop very small cracks over
time, and these cracks can harbour bacteria – including the bacteria that cause
mastitis.

Secondly, check that the milking machine has been recently tested and serviced. This
will give you confidence that the tight, tender teats of freshly calved heifers and cows
are being massaged by effective pulsation and that vacuum is set at the minimum
level possible.


The first few minutes after milking while the teat orifice is still closing are critical in
helping to prevent infection. Splashes of mud and manure onto teats and teat ends can
place millions of potentially infectious bacteria into the area around the teat orifice
(and cow manure is often the most common source of Strep uberis).

To reduce this risk, avoid the need for cows to walk, stand, or lie down in mud and/or
manure for the first 20 minutes or so after milking. Critically examine the dairy exits
and the laneways leading away from the dairy to see if improved drainage or regular
cleaning will reduce the level of mud and cow manure and thus lower the risk of
contaminating the teats of the recently milked cows.

Also ensure there is effective teat disinfection post-milking with good coverage from
an effective teat spray product (either ready-to-use or correctly mixed with high
quality water) containing emollient.

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Early detection of clinical cases pays off

“The sooner you find a clinical case, the sooner you can treat it.”

The sooner a clinical case is found and treated, the greater the likelihood of both
curing that case and preventing spread to other cows - and the most effective way to
detect clinical mastitis in freshly calved cows costs virtually nothing.

Foremilk stripping (or forestripping) by careful operators can identify early cases of
mastitis – when the chance of cure is higher. The Countdown Farm Guidelines
recommend forestripping all quarters of all cows for the first 8 milkings after calving.

But technique must be good, because if it is done poorly, forestripping may actually
contribute to the spread of mastitis between cows. Ideally, milk should never get onto
the hands of milking staff.

Tips on how to forestrip fresh cows:

       Wearing gloves, squeeze the base of the teat where it joins the udder between
        the thumb and the first two fingers then pull gently downwards, avoiding
        getting milk on your hands.
       Strip onto the concrete or a dark surface or strip cup, never onto your other
        hand.
       Look for clots, strings, wateriness or discolouration in the first few streams of
        milk. Changes in the milk that persist for more than three squirts indicate that
        a cow has mastitis that requires treatment.
       Repeat this for each quarter.
       Quarters with only a few flecks in the first three squirts may be left untreated.
        Mark these cows and check them again next milking.
       Wash your gloves under running water and then dip them in freshly prepared
        disinfectant.

With a little thought and practice, forestripping of fresh cows can be easily
incorporated into a milking routine.

If you don‟t routinely forestrip for eight milkings, then at the very least consider
checking each freshly calved cow both when she first comes into the dairy, and then
again when she is ready for her milk to go into the vat.

Early detection allows early treatment, and early treatment means a better chance of
cure and less chance of spread.

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posted:9/24/2011
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