Wool production
Worksheet 4: Other management practices affecting lambing
answers
Activity 5
1. Planning the most suitable time for lambing involves consideration of
several factors. These include:
 typical weather conditions at lambing time
 availability of feed at weaning time
 risk of flystrike at lamb marking time.
Discuss how each of these factors may influence the time of lambing.
Weather conditions at lambing time
-
cold  lambs don’t have much fat  feel the cold  use
what fat reserves they do have to try to keep warm
lambs die because of the cold
-
wet  ewes with wool are less likely to seek shelter
because they don’t feel cold  stay out in rain grazing,
don’t seek protection behind windbreaks or under trees 
lambs get very wet and cold  lambs die
-
windy  ewes often leave lambs in windy weather  lambs
die of starvation and cold
-
mild  ewes more likely to stay with their lambs  lambs
don’t use fat reserves to stay warm  start drinking and
putting on weight  lambs have a better chance of
survival
Conclusion: lambing time is better planned for the time of
the year when the weather is mild and less likely to be cold,
wet or windy.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
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Wool production
Weaning
Lambs often lose weight when they are taken away from
their mothers  lambs lose weight  ensure there is plenty of
feed (pasture)  weaning should occur when pasture growth
is good.
Lambmarking – should be carried out when the following
match up
- when lambs are 4-6 weeks old
- not in extreme weather conditions (too hot, wet or cold)
- not when fly numbers are greatest to avoid flystrike. Flies
are greatest in number after rain in hot weather.
Determining when to lamb requires making a judgement about the typical
weather conditions that can be expected at lambing time, the quantity and
quality of feed available at weaning time and risk of flystrike at lamb marking
time and making a decision that will decrease the negative impacts of these
factors.
Cold, wet and windy conditions decrease lamb survival rates. Newborn lambs
are already wet and with little fat coverage can experience problems
maintaining the appropriate body temperature. A ewe with a good covering of
wool will not necessarily seek the shelter required by a newborn lamb
therefore leaving her lamb exposed to the wind. Coupled with this, high winds
often make ewes desert their lambs.
Ideally, lambing should be planned to avoid the worst of any cold, wet and
windy conditions that are typically expected in an area.
To decrease losses in number and reductions in the bodyweight of weaners,
weaning time should be planned to coincide with good availability of quality
feed. This means that good management counts back from the time of feed
availability to help determine a suitable lambing time.
Lamb marking should occur when the lambs are four to six weeks old. Ideally
lamb marking should not occur when weather conditions are extreme, either
very cold and wet or very hot. These extreme conditions increase the stress
on lambs. The incidence of flystrike is increased when rain occurs during hot
weather. Lambs that have just been marked are vulnerable to flystrike and it
is therefore best if marking is carried out before the worst of the fly season.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
page 2 of 7
Wool production
2. What options do farmers have for providing shelter for ewes at lambing
time?
Windy weather can kill lambs because the wind chills the
lamb’s body. Ewes are also more likely to desert their lambs
in windy weather.
Woolly ewes are less likely to seek shelter  lambs kept out in
the wind.
Shelter for lambs and ewes can be provided by:

Lines of trees

Hedges

Gullies

Rocky outcrops.
Northerly facing paddocks tend to be sunnier  warmer for
lambs  better for lambing paddocks.
Paddocks on hills  tend to be windier  less suitable for
lambing paddocks.
Tree lines and hedges make excellent wind breaks for lambing paddocks.
Lambing paddocks should not be exposed, that is, on the top of hills and
without wind breaks.
Gullies and rocky outcrops also offer protection for new born lambs from cold
winds. Depending on the prevailing winds, paddocks with a northerly aspect
can offer a sunny location suitable for lambing.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
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Wool production
3. Why may it be useful to draft maiden ewes into a group separate from
mature ewes?
Ewes with their first lambs (maiden ewes) are less able to
keep track of their lambs  mature ewes of ten take lambs
from maiden ewes  keep maiden and mature ewes separate
at lambing.
Mature ewes often take lambs from maiden ewes, which seem less able to
keep track of their own lambs. Maiden ewes should therefore be lambed
separately from adults.
4. How does selection of ewes assist with lamb survival?
The ability of ewes to give birth, feed and care for a lamb is
inherited. Some ewes fail to give birth to live lambs because
they have a small pelvis or the lamb is too big for the size
and shape of the ewe. Other ewes may not have enough milk
or lose their lambs. These ewes should be culled so that these
problems are not inherited and passed onto their offspring.
Ewes that lamb without problem, produce plenty of milk and
care for their lambs should be kept. These characteristics are
valuable and can be passed onto their own lambs.
Rearing ability of ewes is inherited. Repeated failure to rear lambs can be due
to the ewe having a small pelvis or an inherited tendency to produce oversize
lambs. Ewes that fail to rear lambs should be culled to slowly improve the
lambing percentages of the flock.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
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Wool production
5. How can udder faults affect the number of lambs that reach weaning
age?
Ewes can have their teats damaged during shearing or may
have deformed or diseased udders  unable to feed their
lambs  lambs may grow slowly or die  less lambs reach
weaning age or are much smaller and lighter than they
should be.
Ewes with deformed or diseased udders or with teats damaged or
accidentally removed by shearing may have trouble feeding their lambs or be
unable to feed their lambs. This may result in the death of the lambs
decreasing the numbers of lambs that reach weaning age or lambs that have
slow growth rates and low body weights.
6. What can farmers do to decrease of numbers of lambs lost because of
predators?
To decrease the numbers of lambs attacked by predators the
following things can be organised:
 Lambing period should be as short as possible, this means
that rams should not be left with ewes for an extended
joining period and more than one ram should be put in
with each mob of ewes.
 Synchronise lambing to occur on several properties in the
one area so that there is a large food source for the
predators all at one time.
 Carry out a baiting program just prior to lambing and
during lambing. Make sure the baiting program is under
the supervision of the Rural Lands Protection Board.
 Use electric fencing in lambing paddocks to help keep
predators out.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
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Wool production
Farmers can do the following to decrease the numbers of lambs lost because
of predators:
 Ensure the lambing period is as short as possible.
 Try to coincide your lambing period with that of your neighbouring
properties so that your lambing flock is not the only food for the predator.
 Use registered poison baits under the supervision of the Rural Lands
Protection Board.
 Use electric fencing to assist in exclusion of predators from the lambing
paddocks.
7. For each of the management practices listed at the top of the page,
describe how each practice can enhance the welfare of the ewes and
lambs in a breeding flock.
Timing of lambing – new born lambs have little body fat
and are wet from birth  little protection from the cold and
are likely to get chilled if it is windy  can lead to the death
of lambs  stress on ewes. Animal welfare is  if lambing is
planned for a time of the year that is unlikely to be cold, wet
and windy.
Timing of lambing: Newly born lambs have very low percentages of body fat
and are wet from birth. This means that they have little protection from the
cold and have an increased chance of their body temperature dropping
because of the wind chill. This can lead to the death of lambs and stress
placed upon the ewes. Therefore animal welfare can be improved by planning
lambing time for a time of the year that is unlikely to experience cold, wet and
windy conditions.
Provision of shelter in lambing paddocks – tree lines, hedges,
gullies and rocky outcrops can protect lambs from the cold
and wind if the weather unexpectedly turns cold   animal
welfare with less chance of lambs dying and ewes being
stressed due to the loss of their lamb.
Provision of shelter in lambing paddocks: can mean that if the weather
unexpectedly turns cold, wet or windy the ewes can seek shelter from the
wind which can be particularly damaging to newly born lambs. This can mean
that lambs do not die and that ewes do not become stressed by the loss of
their lamb.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
page 6 of 7
Wool production
Drafting of ewes into age groups to allow for mothering
behaviour – ewes with their first lambs (maiden ewes) are
less able to keep track of their lambs than older ewes 
mature ewes of ten take lambs from maiden ewes  by
keeping maiden and mature ewes separate at lambing stress
on ewes and lambs is  with maiden ewes able to keep track
of their lambs more easily and the lamb is able to bond to its
mother.
Drafting of ewes into age groups to allow for mothering behaviour
decreases the incidence of robbing and cross-mothering. Young first time
mothers are often unable to keep track of their lamb and an older ewe takes
the lamb. This can cause stress to the ewe who is unable to find their lamb
and stressful to the lamb that is unable to bond to one ewe and may be at risk
of being abandoned.
Selection of ewes – ewes that are able to lamb easily and feed
their lambs  healthier lambs that are more likely to survive
this is good animal welfare.
Selection of ewes: having a breeding flock of ewes that give birth easily and
are able to mother and feed their lambs means that more lambs survive and
the health of the flock is enhanced.
Consideration of physical features of the ewe – same as
selection of ewes, ewes that cannot feed their lambs because
of bad udders or missing teats result in undernourished
lambs that will not grow well and maybe die.
Consideration of physical features of the ewe: by monitoring the health of
ewes’ udders at crutching time, those ewes with bad udders and missing teats
can be culled. This can assist farmers avoid ewes with udder problems
lambing and being unable to feed their lambs.
Control of predators – this is essential for good animal
welfare  as good animal welfare involves protection of the
stock from predators.
Control of predators: dingoes, foxes and feral pigs can kill otherwise healthy
lambs leaving lambless ewes. Control of predators can decrease the
incidence of this occurrence.
Animal welfare in agriculture
http://www.schools.nsw.edu.au/animalsinschools/
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