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WORKING
TOGETHER
FOR A HEALTHIER FUTURE...
9
LIVESTOCK MATTERS
HERD FERT I L I TY
Investing in fertility
to keep dairy
cows in the calving block
Veterinary surgeon
Dave Gilbert
XLVets practice
Lambert,
Leonard and May
Vet Dave Gilbert of Lambert Leonard and
May Veterinary Practice explains: ‘In low
input grass-based systems, synchronisation
programmes are an essential tool because they
enable calvings to take place at the start of the
block. This gives the animal a longer recovery
time before the next breeding, more days in
milk, and a reduced risk of being culled due to
slipping out of the block.
‘Another benefit of these programmes is that
they prevent heifer replacement calves from
being born late in the block where their
younger age would create challenges in
getting them to meet the growth target to be
ready for breeding in time.’
However, Dave believes some farmers are
delaying initiating fertility treatments to save
money on medicine and vet costs, but losing
more money through having cows calving late
in the block, or outside of it.
Act or ‘wait and see’?
Dave works with a number of spring block-
calving herds in Cheshire and Staffordshire,
on low input grass-based systems.
Dave explains: ‘The ‘traditional’ approach is to
wait for cows to come into heat, allowing them
a couple of weeks to do this before taking
action. Some of them will express oestrus
naturally, and so money will have been saved
on fertility treatments. Others will require
treatment, and for those, time will have been lost.
Alternatively, a more proactive approach can
be taken, and all non-cycling animals treated
at the start of the breeding period.
To quantify the benefits of taking a proactive
approach versus the traditional ‘wait and see’
approach, Dave carried out a trial in the
spring of 2015.
On three block-calving farms, heat detection
aids were applied to cows, as was routine,
four weeks prior to the commencement of
breeding. Animals were then monitored for
heat expression.
After three weeks all cows not seen in heat
were examined. Those with uterine or ovarian
disease were treated as normal on the farm.
Then any non-cycling cows were randomly
allocated to either a ‘proactive synchronisation’
group, or a ‘wait and see’ Control group.
The synchronisation group cows received a
programme of fertility treatments which included
an intra-vaginal device which gives a slow
release of progesterone to top up the cow’s
own progesterone and help kick-start cycling.
In the Control group, cows were given 14
days to come in heat so they could be served.
Those showing no heat were re-examined and
treated as necessary.
The benefits of taking a proactive approach
were clear; as expected, the 3-week
submission rate for cows treated proactively
was 100%, but only 84% in the Control
group. On average, proactive treatment
reduced the number of days to first service by
12 (from 14 days in Control group to 2 days
in the treated group), and the days to
conception shortened by 7 days (from 26
days to 19 days in the treated group).
Dave explains: ‘This had a direct effect on
the 6-week in-calf rate, which was 69% in
the treated animals, an increase of 13% over
the Control group.’
(See Figure 1)
DAVE GILBERT, LAMBERT, LEONARD AND MAY
On dairy farms operating a block-calving system, a range of synchronisation
programmes are available, through vets, to assist breeding and ensure that cows
and heifers calve within the block, and can therefore stay in the herd.
Submission rate 6w in-calf rate
Empty%
Figure 1:
Average results across the 3 farm
s
69% Proactive treatment
’Wait and see’
An example of an intra-vaginal device that
releases a controlled flow of progesterone to
the cow
100%
84%
69%
56%
17%
29%