Basic HTML Version
S P E C I A L F E A T U R E
S
pring is when all the action happens on dairy farms in New Zealand. We jumped
from waiting out the dry period to being flat out into calving with each vet from the
Ashburton clinic covering 18,000 cows per person. Sounds like a lot but actually
over the whole season (3 months) I only had to assist around 75 calvings. Much of this
is down to selecting sensible bulls and good feed management of the cows.
Spring in NewZealand
New Zealand Calving Season 2010
Of the calvings I assisted, probably 90% had
dead calves inside but probably only 10%
of these were rotten, which was a pleasant
surprise as I had heard bad rumours about
New Zealand calvings before I started.
Perhaps farmers out here are becoming a
little more observant to these problems than
they used to be
?
However I can now
appreciate it's no easy job at calving time
to monitor these numbers of cows.
Most farms would run the herd in 2-3 groups,
the milkers, colostrums (up to 4 days calved)
and springer mob. Later calving cows might
be grazed off farm until they get closer
to their due date, enabling better feed
management. Many farms will feed some
supplement during this time; maize silage is
commonly spread out. Some are fed
pre-calving on swedes/turnips/fodder beet.
Magnesium is supplemented through
dosetrons (daily pulses of 60-70g/cow into
the water) and spread on the pasture/silage.
Most colostrum cows and some milkers will
also have limeflour spread or dusted as a
calcium supplement post calving.
In the first 3 weeks of calving many farms
will have 30 or more cows calving per day,
this then slows a little usually in the following
3 weeks and then drops right back for the
tail end of calving. Calving spreads can
vary from 9 to 14 weeks. Good farms will
meet a 6 week target of 79%, so all in all
it's a very busy period what with calf
management, metabolic problems,
induction cow management and several
cow groups.
Induction cows are cows that have been
mated too late to calve naturally within the
farm’s planned calving period. We induce
cows 6-12 weeks before their calving date;
any later than this makes it more likely a live
calf will be born and any earlier will mean
the cows won't come into milk well or will
fail to respond to our injections. This group
of cows will have been created back at
scanning when we aged the foetuses. They
need to be kept separately and given
supplementary feed. We give all these cows
selenium and vitamin supplements to help
prevent retained membranes. As I mentioned
in my last article, inductions are slowly being
phased out here so in a few years this aspect
of New Zealand dairy management won't
exist, for good or for bad I guess depending
on your viewpoint.
Amy Avery
Endell Veterinary Group
25
LIVESTOCK MATTERS
WORKING
TOGETHER
FOR A HEALTHIER FUTURE...