FOR the second year
Intervet/Schering-Plough Animal
Health has collected information
about mastitis from 10% of the
11,256 dairy
producers in
England and Wales.
There are some
rather surprising
findings, which have
been examined by
Andy Biggs and James
Allcock. Impressions
gained from work with
clients may not reflect
the overall trends and
there is no doubt that
changes have taken
place, even from 2009
to 2010.
All regions of the
UK are represented and
herd sizes from below 50 cows to over
500. Two-thirds are between 100 and
250 cows. Three-quarters of the herds
are Holstein Friesian with Friesian and
Channel Island breeds also included.
The majority of the farmers (80%)
indicated that their herds had a cell
count below 200,000 cells per ml with
9% below 100,000. Only two farmers
admitting to a cell count above 350,000
cells per ml.
It is worth considering how these
cell count data compare with the
situation in practice herds, as cell count
is relatively easy to collate. Some of the
management aspects of the survey may
be more difficult to interpret for
lessons learned of value to dairy
clients.
Higher milk yields
More than 75% of the farmers
indicated that over half of the cases of
clinical mastitis occur within the first
100 days of lactation, generally after
the first month of lactation,
presumably coinciding with peak yield.
This may indicate the issue of energy
balance related to yield perhaps, but
nutritional management was not part
of the survey.
However, between the 2009 and the
2010 study, more of the herds
recorded higher milk yields, both in
terms of yield per cow and gross milk
sales. In excess of 150 of the herds
reported sales of over 2 million litres in
the year up to the summer of 2010.
With some herds already feeding
winter rations because of a shortage of
grass, an early spring may be an
important element for the next annual
sales or the margin of sales to feed
purchased will be cut.
Approximately 30% of the farmers expect to treat fewer than 20 quarter
cases of clinical mastitis per 100 cows
per year, with half indicating 20 to 50
quarter cases. It appears that farmers are using combination
antibiotic therapy
regularly to treat
clinical cases (around a
third of the dairymen
who completed the
survey).
Overall, a third of
the farmers select
Cobactan as their first-
line treatment but it is
not clear whether this
is the same third who
indicated that they use
combination therapy.
The aim would be to
promote a compatible injection together with
an intramammary and, glancing at the product literature, combination therapy
indicates higher concentrations of
antibiotic in the infected quarter and
therapeutic levels in the blood plasma.
It would be interesting to know
whether there is an increasing use of
combination therapy for treating
clinical mastitis, whether the regime is
seen to be successful and if a full
course of injectable is used or just an
initial booster dose.
Most (80%+) of the farmers use
teat sealant in combination with dry
cow therapy, roughly half routinely and
others some of the time.
More information would be
welcomed about the treatment of high
cell count cows. Over half of the
farmers indicate that they treat these
animals but the detail of cow selection,
the therapy used and the value
perceived is not within the report.
There is information about mastitis
in heifers with 16% of the farmers
reporting that more than one in 10
heifers suffered mastitis during their
first lactation. It would help to know
whether these cases are related to
difficulties with aspects of milking,
issues of not getting in calf or not
settling into the milking herd
environment.
No bacteriological tests
Bacteriological milk testing does not
seem to be high on the list of actions
for these farmers. Fewer than 20% had
tests carried out on three or more
occasions in the year. A third said that
they never utilised bacteriological tests.
Of the results that were available,
the proportions were Strep. uberis
(36%), Staph. aureus (31%) and E. coli
(23%). These figures are consistent year on year and
over two-thirds
of the farmers
report
difficulties with
clinical mastitis
treatment. These
farmers regularly use four to six
intramammary tubes per case with 10%
of the farms using up to 10 tubes.
As expected, there is a variety of
teat preparation options with around
half of the herdsmen not washing teats
before milking. Pre-dipping or pre-
spraying is applied to about a third of
the herds, with medicated wipes and
dry wiping being used by a few
enthusiasts. Herdsmen are wearing
gloves for milking on 70% of the
farms.
Nearly all the farms apply post-
milking disinfection in some form with
an even split between spraying and
dipping. Over half of the farmers say
that the cows are
foremilked before
applying the clusters.
Within the survey,
automatic cluster flushing
is utilised by a few
farmers as an alternative
to dipping or spraying,
whereas a large number of
the farmers (44%)
indicate that cluster
disinfection is carried out.
Contaminated milk transfer
At various meetings, Roger Blowey has
surprised audiences by demonstrating
that one or two millilitres of
contaminated milk can be transferred
between cows from the short milk
tube.
Various options are available for
cluster flushing including a bucket of
disinfectant, use of a jug and bucket,
manual sprays, air wash and automated
dipping and flushing.
Roger has reported on the cluster
flush mechanism developed by Vaccar
utilising sanitised water and
compressed air. The system is fitted to
existing milking units and enquiries
indicate that over 500 of the systems
have been installed in recent years with
a similar number of installations from
other manufacturers.
One of the claims for cluster
flushing is that the farmer has
“substantially reduced vets bills”.
The value of this survey is possibly
linked to whether what is taking place
matches veterinary advisers’
expectations of the management of
herds under their care or whether it
encourages a more detailed approach to herd management awareness.
One of the aspects that Andy
Biggs raised is the waiting time for
cows in the collecting yard. The effects
on mastitis could be related to standing
time. Standing time is recognised as a
bad thing in relation to lameness (or
reduced mobility), dietary issues and
fertility performance among others, as
the cows are not eating or lying down.
One of the measures could be the yield
of the herd in relation to the number
of milking units.
Standing time increasing
A common concern is the higher
production with management and
facilities not keeping
pace with performance.
As yield increases and
the number of milking
units remains the same,
the milking time and
standing time will
increase unless positive
steps are taken to
arrange milking into yield groups.
Three-quarters of the farmers indicated that they had monthly milk
recording for the herd but the survey
does not indicate whether cows are
grouped for milking. Are the herds in
the survey, with increasing yields,
suffering mastitis problems that will
need to be addressed not by bigger and
better therapy but by milking time
management?
An analysis of the national survey
is available from the Cobactan folk as a
print-out or computer thumbstick.
There is a great deal of data here and
any suggestions for further points of
analysis or additions to the next
national survey are being sought (tim.hickman@sp.intervet.com).
It may be possible to have updates
to the survey introduced via the web but
the option, introduced this year, for the
farmers to provide information online
rather than by post was only taken up
by 42 farmers. However, being able to
download details and conclusions from
a website may be of interest to both
farmers and veterinary surgeons.
There are clearly many points of
detail related to the control of mastitis
that continually need to be addressed.
