Basic HTML Version
C A S E S T U D Y
Adrian Salter
Bremridge Farm,Crediton
‘Numbers in the transition group vary from
day to day so whoever is on feeding duty
needs to ensure enough feed is made for
the animals present...’
Adrian Salter
Clinical and sub-clinical levels of milk fever have been a problem for
Adrian Salter, herd manager to the 500-cow Nuthatch pedigree herd at
Bremridge Farm, near Crediton.
Case Study:
Bremridge Farm
Herd average yield is just over 9,500 litres,
and cows calve all year round. The main
herd is housed indoors all year round. The
low yielders graze by day and are housed at
night while far-off dry cows graze outdoors up
to 3 weeks before calving when they are
brought indoors to form a transition group.
Hypo-calcaemia has been a problem on the
farm because the high yielding Holstein cows
struggle to physically eat enough of the diet
around calving.
Tony explains: ‘A cow is, naturally, very
pre-occupied just before and after calving,
and takes her focus off eating. Then, when
she is returned into the main milking herd
there can be competition for food in the
new social group - this all adds to stress
levels, further reducing her attention on
eating. So managing her re-introduction
to the herd after calving is vital in reducing
milk fever cases.
At Bremridge Farm, cows are fed a transition
TMR diet which is deliberately formulated to
be similar to the milking ration, so that the
right bacteria are already geared up once
production goes into full swing. It's also a
high fibre diet, to keep the rumen large,
ready for the increased levels of feed intakes
needed to support high yields.
The daily transition TMR ration per cow, those
three weeks off calving, consists of 18kg
maize silage, a 4kg fibre 80:20 mix of
straw:grass silage, 1kg of protein blend and
1kg of dry cow Omega, 150 grammes dry
cow minerals, and 250g magnesium chloride
(MgCl) flakes.
Tony explains: ‘The magnesium chloride flakes
acidify the blood and this helps the calcium
mobilisation from the bones. Intake levels are
important, so these diets must be mixed to
ensure the same density throughout. The levels
fed to the Nuthatch herd are at the top end
of normal. Magnesium chloride is not a very
palatable ingredient, so care must be taken
to ensure that feed intakes do not decrease.’
Adrian adds: ‘Numbers in the transition
group vary from day to day so whoever is
on feeding duty needs to ensure enough
feed is made for the animals present. They
shouldn't be coming to the barrier at feed
out, because they shouldn't have been
allowed to get hungry in the first place.’
Tony and Adrian review the herd's nutrition
on a monthly basis with an independent
nutritionist and adapt the ration taking into
account factors such as yields and dung
consistency. They also take a close look at
intakes and any metabolic problems during
routine weekly fertility visits.
Despite the use of MgCl flakes, cows were
still getting metritis (whites) after calving,
sometimes for up to 6 weeks. Tony explains:
‘We carried out an investigation looking
at possible infectious diseases, energy
deficiencies and trace element shortages but
found no problems in these areas. Despite
having few clinical milk fevers we suspected
a calcium shortage around calving which
was stopping the uterus closing down
and involution.’
So now all cows are dosed with a calcium
solution straight after calving and then kept
under observation for a week. Adrian
explains: ‘Ideally we'd like to monitor
individual cows, but we don't have the
facilities and it would be a lot of extra work,
plus they don't like being kept out on their
own. So now we keep fresh calvers in a
small group for the first week, where we
keep an eye on them before they go back
to the cubicles. We also keep check that
their milk production is on a rising trend.
If it isn't, then it's a sign the uterus may have
some infection.’
During his regular routine visits, Tony carries
out a post-calving check on all cows,
scanning the uterus after about three weeks
to assess its size, as well as the quantity,
thickness and discoloration/infection of any
mucous still present. Tony says: ‘Farmers can
make their own checks by carefully dipping
their hand into the cow's vagina to check the
mucous is clear and not smelly or containing
pus. Rectal temperature should also be taken.
Tony adds: ‘Attention to dry cow management
and nutrition is key to preventing cows
from becoming hypo-calcaemic. Whilst
avoiding milk fever and the 'downer cow'
is often the main aim, just as important is the
prevention of sub-clinical milk fever which can
be responsible for cows failing to get back
in-calf, and having a longer term effect on
herd fertility performance.’
SUMMER 2010 ISSUE
LIVESTOCK MATTERS
16