| Sheep & Lambing
Maximising the performance of lambs
In order to maximise the performance of lambs, it’s important to understand their energy requirements.
p until eight weeks of age,
lambs are dependent on their
mothers for milk so the priority
is to maximise energy intake
into ewes to drive lactation,”
said AHDB Beef & Lamb senior
livestock scientist Liz Genever.
“Post-eight weeks, their performance
becomes more dependent on the quality of the
grass or feed they consume, which has
consequences for how the group needs to be
managed.”
Make the best of grass
The most economical way of feeding ewes
and lambs is with grazed grass, so investing
time and effort into getting that right will pay
dividends.
The grazing targets for ewes and lambs
when set stocked is 4-6 cm, with limited
evidence of benefit if ewes are supplemented if
the grass is over 3 cm. This may alter if grass is
poor quality or the ewes are rearing triplets.
U
Once lambs are starting to eat more grass
(from four weeks) the priority is to give them
access to high-quality feed. At this point,
rotational grazing could be used to control
supply and demand, with 8-10cm being the
pre-grazing target and 4-6cm the post-grazing
target in this system.
“Grazing pasture at the right height will
ensure growing animals are eating high-quality
grass,” Liz said.
“The leaf has more than 11.5 MJ ME/kg DM
and is the most nutritious part of the plant. The
stem has only 10.5 MJ ME/kg DM, so planning
a grazing strategy with this in mind will help
optimise nutrition for lambs.”
Creep feeding
For producers with low quality or limited
grazing, creep feeding can be a good option
and help maintain growth rates. However, creep
feed is expensive.
“Research has shown that lambs on wellmanaged, re-seeded grazing can match the
performance of lambs supplemented with
creep feed on poorer permanent pasture, so
there must be a real requirement to justify the
investment,” Liz said.
The most economical way of feeding ewes
and lambs is with grazed grass
Lambs introduced to creep during the first
two to three weeks after turnout can be
expected to eat 40-50kg per head by sale if it is
offered ad-lib and the sward height is around
4cm. Lambs on restricted grazing with limited
creep feed will gain on average an extra one kg
liveweight for every 5-6kg of creep feed
compared with un-supplemented lambs.
Giving lambs the best grazing ahead of
ewes, known as forward creep grazing, is a
good way to prevent the need for creep
feeding.
Identify any gaps
It is important to identify the likely shortfall in
grass availability over the season, so the gaps
can be managed in a way that suits your
system, according to Liz.
“Encouraging white clover would be a
priority as it helps to counter the dip in grass
quality and quantity in the summer,” she said.
“The plant and the animals eating it need to
be managed carefully, but it can increase lamb
liveweight gain by up to 15 per cent.
Weaning decisions
Research work is showing there is limited
advantage of delaying weaning beyond 90
days of age, unless lambs are close to
finishing.
“By this age, ewes and lambs are directly
competing for grass and it is more costeffective to prioritise good grass for growing
lambs rather than ewes,” Liz said.
“Ewes can be weaned, dried off and then
sorted for body condition score.”
Weaning slightly earlier also means that
ewes are given plenty of time to recover body
condition before the next breeding season and
can be very useful to tidy up pastures.
Monitoring performance
Optimal feeding and monitoring grass is
important, but so is keeping track of lamb
performance. Regular handling and weighing is
a good way to highlight any issues.
“In order to build up a true picture of how
individual lambs and the overall flock is
performing, good monitoring and record
keeping is essential,” Liz said.
“Measuring average daily liveweight gain to
weaning (kg per day) provides information
about maternal performance, grass availability
and parasite control.
“It’s also worth looking back at scanning,
lambing and turnout records to understand
how this year compares with previous years or
industry averages. Lamb losses can be
calculated against the number of lambs
scanned to see how the business is tracking
against targets.”
More information can be found in the AHDB
Beef & Lamb Better Returns Programme (BRP)
manual Growing and Finishing Lambs for
Better Returns. This and a range of other BRP
resources can be downloaded from AHDB Beef
& Lamb website.
44 | Farming Monthly | April 2016
www.farmingmonthly.co.uk