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LIVESTOCK MATTERS
14
SPRING 2011 ISSUE
F E R T I L I T Y S U R V E Y
Targets for culling due to fertility-related
issues are usually around 5-7% but, of the
respondents, only 36% were achieving this,
with some units seemingly having a culling
rate of between 15-25% due to poor fertility.
Post-calving uterine infections are often a
reason behind fertility issues, as they can
delay signs of heat and lead to less viable
eggs being released by the cow. In fact,
it is thought that the vast majority (80-90%)
of intensively housed cattle undergo a
bacterial contamination of some sort at,
or soon after calving.
Not all of these contaminations will lead to
infection. But certain risk factors can be
identified - particularly metabolic problems
such as milk fever, retained cleansings and
ketosis - which increase the likelihood of
infection persisting and adversely affecting
herd fertility.
Understanding uterine health
The survey tried to identify whether farms
considered endometritis or metritis to be
the main post-calving problem. The answer
to this was unclear, perhaps because
respondents were unsure of the difference
between the two conditions.
Around 40% of dairy cows develop
metritis within the first week post-calving
and 20% go on to develop clinical
endometritis (whites), with sub-clinical
(unseen) endometritis being even more
common. And while everyone is familiar
with the problem of whites, studies have
shown that as many as 50% of cases
could be being missed.
Having procedures in place to detect
endometritis is very important. Ideally all
cows are examined in good time before
the breeding is due to start, but at least
those with a high risk of endometritis, to
ensure as many affected cows as possible
are picked. Early treatment with Metricure
®
(the only licensed antibiotic treatment for
endometritis) is advisable but hormonal
treatments are also invaluable and your
vet will be best placed to decide on the
treatments for individual cows.
I N S UMMARY
The findings of this survey have a very
clear list of actions for dairy farmers
throughout the country - don't just accept
the performance of your herd, set targets
and work out how to improve performance.
Although there may be a cost
involved, work with your vet, and you
will soon see a payback as CI reduces,
empty days are cut, there are fewer
repeat services and a lower level of
post-calving problems.