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X LV E T S SCHOL AR SH I P
I
can't believe my first year in New Zealand is almost up! Finally I am
beginning to feel I have some idea of how farming works out here, and
actually am surprised at how different certain aspects of it are from dairy
farming at home.
XLVets New Zealand
- the final season
Amy Avery
Endell Veterinary Group
Herd size (1,000 vs 200 cows), management
setups (corporate/shareholders vs family
owned), grazing all year round (vs housed
cows) and cow genetics (Friesian vs Holsteins)
all add to the differences between farming in
New Zealand and the UK. These affect
animal health in many ways; economic
priorities often are different, for example,
preserving pasture and cow condition are
more important than milk sold in times of
feed shortage. Cows yield far less and are
more robust genetically so appear far less
susceptible to many production diseases we
see every day in the UK, but exposure of
cows to all weathers can leave them very
susceptible to other conditions such as
metabolic problems after calving or heat
stress in summer.
The last few months here have mainly
revolved around mating programmes. From
what I have seen feed seems to be the
crucial factor here, and getting condition
back on cows post calving is essential.
However this is often not easy because
weather, and therefore pasture growth in
spring can be very unpredictable and it is
one of the times of year where supplement
feed here can be really important.
Following calving, for many herds, we would
metricheck routinely during milking. This is
where we check for uterine infections to
hopefully enable us to treat the majority of
them before mating starts. Most herds would
aim for around 70% of cows to be cycling
by the time they start mating. Many farms will
monitor this by tail painting cows 4 weeks
before the start of mating. This allows them
time to deal with the non-cycling cows if
necessary. Some will separate non-cyclers
and thin cows at this time and try to feed
them preferentially. Others will use hormonal
treatments and get them cycling more quickly.
Interestingly there are differences between
how cows in different systems, in different
parts of the world, respond to different fertility
treatments. Perhaps due to sheer cow
numbers needing treatment at one time,
most farmers prefer us to use a blanket
treatment on all their non-cyclers rather than
have us examine the cows' ovaries and treat
accordingly. One of the more commonly
used programmes involves two injections and
a progesterone implant followed by fixed
time AI at the end. The earlier the non-cyclers
are treated, usually the better chance they
have of getting in calf in time.
Tail painting weekly can also be used to
short cycle cows with the aim of serving
most of the herd in the first 10 days of
mating. This may mean cows get the chance
of an extra service before the mating cut off
date. However it also means they will have
a very concentrated calving and the risk of
a feed shortage following a bad winter.
For most, mating would run for anything from
9 weeks up to 16 weeks, but this year with
the change in induction code most have
brought it down to 12. Usually there will be
around 6 weeks of AI followed by bull
mating, although each farm differs slightly.
Few farmers do their own AI as most are
busy enough as it is and there are two large
companies which do the majority of it out
here. Then a new set of young bulls, usually
2-3 year olds, will be put out each year to
finish. It will be interesting to see how all the
different mating practices have faired at
scanning time in a couple of months!
Over the last year I have learnt a huge
amount about New Zealand dairy farming
and have really enjoyed the work. I'd like
to thank XLVets for their support and
sponsorship towards this. I hope you've
enjoyed my articles.
SPRING 2011 ISSUE
LIVESTOCK MATTERS
18
Metricheck device
Tail painted cows
Injecting prostaglandins