Page 15 - Livestock Matters - Winter 2012

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Improving output potential
Steps can be taken throughout the lamb
production cycle to maximise the number of
lambs produced. Ensuring ewes are at target
body condition score at key stages ensures
they are fit and robust, which will help.
Stress can increase losses, especially during
early and mid-pregnancy, so handle ewes
quietly at this time. Prolonged cold weather
or limited grazing can also stress them at this
critical time, and can cause embryo death.
The size of the lamb can be a reason for a
loss - either too big or too small. This problem
can be avoided through careful feeding
pre-lambing.
Use body condition scores and the results of
scanning at around 70 days to group ewes
into similar batches. Pay special attention
to those carrying triplets which require
supplementary feeding sooner than those
with twins or singles.
It is essential to analyse winter forages and
ensure rations are balanced. Aim for a tight
lambing period so most ewes have a similar
feed requirement at the same time.
Underfeeding pregnant ewes can lead to them
giving birth to light or sickly lambs. It can also
reduce their milk yield which will reduce lamb
growth rates and increase the risk of mastitis.
EBLEX recommends asking your vet to blood
test a group of ten ewes, three to four weeks
before lambing and ideally four hours after
the last supplementary feed. The results will
show the levels of beta-hydroxybutyrate
(BOHB) and urea. This will show whether the
animals are receiving enough energy and
protein in their diet.
Give lambs the best start
in life
Still-births are the biggest loss recorded at
lambing. These can be due to infectious
diseases, but many occur from difficult
lambings through injuries, trauma or lack
of oxygen.
Lambs that are poorly presented can become
stuck inside the ewe and 'drown' before they
make it out. High birthweights and disturbance
levels increase the risk, as do high litter size
and low supervision levels.
Mothering ability varies, but ewes in good
condition, fed well and not disturbed in labour
and just after, tend to be good mothers.
It is essential that lambs receive 50ml/kg of
colostrum within the first four to six hours of life
and continue to drink during the first 24 hours
of life. Within this time a 5kg lamb should
consume at least 1 litre of colostrum.
Studies show that many lambs, particularly
triplets and small lambs, do not receive
sufficient colostrum. If extra supplies are
needed, colostrum from another ewe is ideal.
Frozen cow's colostrum can be used but
discuss the risks of anaemia with your vet.
Poor weather around lambing can cause
significant problems, especially if wet, cold
and windy. Lambs are unable to maintain
body temperature for long periods especially
if colostrum intake has been insufficient.
The biggest causes of young lambs dying are
exposure and starvation. Exposure leads to
hypothermia, caused when a lamb loses heat
quicker than it can produce it.
Starvation also leads to hypothermia - in
essence this is a shortage of blood glucose in
lambs over 12 hours old, which have none of
the brown fat they were born with left, and no
colostrum in their stomach.
Lambs that are suffering from hypothermia
need assistance. Take their temperature before
deciding a course of action to revive it.
In mild cases (37 o - 39 o C), dry the lamb,
feed with a stomach tube and return to its
mother. In severe cases, where the animal's
temperature has dropped below 37 o C, the
lamb may need warming, as well as being
stomach-tubed or given a glucose injection
to get it going.
REDUCING LAMB LOSSES
WINTER 2012 ISSUE
LIVESTOCK MATTERS
14
Shepherd Nick Smith of TP
Gilman Ltd, Manor Farm,
Tixover, Stamford.
4,300 mules 7,000 lambs: finishing
all lambs off grass with creep;
ewes are on fodder crops during
the winter.
‘We have tracked losses properly for the past
five years using a bin system for all dead
lambs wet or dry. Wet lambs are classified
as those that are aborted, mummified or
rotten and dry lambs are those that have
been laid upon, wet mouth, starved etc.
In the past we have experienced quite a
lot of abortion which we now vaccinate for.
But most of the wet lambs that die, or that
have been born dead are very often put
down to an abortion of some kind.
To identify at what stage we are losing
lambs, and what age and type of ewes
are losing them, we take records at five
key events - when we scan the ewes, when
they lamb, when we turn them out, while
the lambs are in the field and finally at sale.
Analysis of the data highlights where the
losses are occurring. For example we can
pinpoint how many ewes are reabsorbing
or aborting their foetuses from the number
of lambs they give birth to. The number of
deaths on the shed floor shows us how
many ewes are giving birth to dead lambs
or weak lambs. The birth to turnout figure
highlights the numbers dying after birth -
perhaps due to poor colostrum intake or
poor stockmanship in the lambing shed.
Having this information helps us allocate
resources more effectively. If we don't lose
any lambs in the field, then we know our
flock health planning policy is working. But
if most of the losses are happening in the
lambing shed - then maybe investing in an
extra pair of hands at lambing will be
more than worthwhile.
Sometimes the information we collect makes
dismal reading, but that is no reason to stick
our heads in the sand. Having the figures
means we can identify where we have to
work harder, and most importantly when.’
Case Study:
Manor Farm
There is much more information in the EBLEX Sheep BRP manual 14: Reducing
lamb losses for Better Returns. Available online at www.eblex.org.uk or free by
emailing
brp@eblex.ahdb.org.uk
or
calling 0870 241 8829
. Or in our Reducing
Lamb Losses DVD, to view go to
http://www.eblex.org.uk/returns/videos.aspx
or email
brp@eblex.ahdb.org.uk
with your name and address for a hard copy.