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Case Study
Rober t Graham, Lazenby Moor
Farm, Minskip
Dan has been evaluating the benefits of
milk progesterone testing with six of the
practice's dairy clients. Amongst them is
Robert Graham of Lazenby Moor Farm
where the 180-cow herd is averaging
yields of 9,700 litres/cow/year. Jonathan
Statham makes fortnightly routine
fertility visits.
Robert and his staff rarely see a cow
showing the primary signs of standing
oestrus. So, a few years ago, the Heatime
activity monitoring system was introduced.
This has been very beneficial, and
contributed to the herd's excellent fertility
performance: a calving interval of 386
days, and a 100-day in-calf rate of
over 60%.
However, some cows still only exhibit
a marginal degree of extra activity when
in oestrus. So despite using the monitors,
it can be questionable whether to serve
cows or not; they could either be in heat,
or could be pregnant and showing
marginally increased activity rather than
genuine signs of heat.
At Lazenby Moor Farm, where cows are
showing marginal increased activity at
19-22 days post-service, the policy has
been to serve them again.
However, Robert believes there is still scope
for improvement and would like to further
tighten the calving interval. He has been
using milk progesterone testing for cows
which are showing borderline levels of
extra activity, to obtain a more reliable
confirmation of oestrus.
It is already proving beneficial. For
example, on one occasion Robert was
faced with 12 cows which were either
18-24 days post-service and/or showing
marginal heat activity. Did these need to
be served, or not
?
The milk progesterone tests showed that
four cows had low levels of the hormone,
indicating that they were bulling, and
should be served. However, eight cows had
high progesterone levels - so they were
either in-calf or mid cycle, and definitely
should not be served. At Jonathan's next
fertility visit, pregnancy diagnosis of these
eight cows showed five to be pregnant. In
this case, milk testing had saved the cost of
eight semen straws, and potentially averted
abortions and extended calving intervals.
(See panel for examples.)
Robert comments: ‘Progesterone testing is
proving a valuable tool, and becoming part
of the routine here. It allows us to identify
cows returning to heat that we would have
previously missed.’
Benefits of milk
progesterone testing:
●
Detect silent heats
●
Prevent mistiming insemination
●
Investigate non-cycling cows
●
Investigate poor fertility
●
Helps improve PD-positive rates
●
Detect non-pregnant cows at day
19-24 after serving
●
Prevent inseminating an already
pregnant cow
●
Be sure of calving date and start
of dry period
●
Use with other heat detection tools
to remove false positives
Cows with marginal heat activity
Progesterone tested at 21 days
post-service as suspected return to heat.
Test showed high progesterone indicating
she was in-calf. She was not served.
At fertility visit, she was confirmed
PD-positive at 35 days.
Heat detection
- the big picture
Regular fertility visits help ensure that all
cows return to cycling normally, thereby
increasing the number of cows that can be
served and ultimately, put back in-calf.
Fertility visits can vary from being weekly
to monthly, depending on herd size and
system. They provide the opportunity for
the vet to examine cows and heifers to
check they are pregnant and carrying a
live calf. It's also an opportunity to
investigate animals that aren't cycling
normally or may have reproduction-related
disease. In this way, calving index is kept
in check on many farms.
Jonathan explains: ‘It's estimated that
modern Holstein cows may only show heat
for 3-6 hours, and will mount others only
once or twice per hour. So heat detection
tools, used together with herd records, can
be very beneficial in improving fertility.
‘Their use can also reduce the number of
PD-negatives presented at a fertility visit.
So this saves time. Pregnant cows will still
need inspection to ensure they are carrying
live calves, however more focus can then
be given to proactive post-calving checks
and other infertility issues.’
He adds: ‘In order to express oestrus,
cows need to be in a state of good health
and nutrition. So it's also important to stand
back and look at the big picture to remove
detrimental factors such as poor nutrition,
stress and lameness.’
CASE STUDY
WINTER 2012 ISSUE
LIVESTOCK MATTERS
8
Cow 2398
Progesterone tested at 23 days
post-service following borderline activity
spike - a suspected return to heat. Test
results showed low progesterone: heat
confirmed. Cow served.
Cow 2422
Robert Graham
Cow with transponder
Jonathan Statham using ultrasound