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SUMMER 2016 ISSUE
LIVESTOCK MATTERS
6
SHEEP FERT I L I TY
He farms in partnership with his father Bill,
at Coombeshead Farm near South Molton
in Devon. The farm is 900ft above sea
level, and very exposed.
The Geens run three different flocks, on two
systems. A pedigree Lleyn flock and a flock
of Lleyn crosses are lambed indoors from
the beginning of March. A third flock, of a
new breed, the Exlana, is lambed outdoors
(see panel)
.
Matt fully utilises the benefits of EID to
improve the performance of his flocks.
Lambs are weighed at birth, at 8 weeks
and then every 4 weeks. Both the Lleyn and
Exlana flocks are Signet-recorded providing
Matt with Estimated Breeding Values (EBVs)
and breeding indexes.
Matt is keen to improve his Lleyn flock,
but wants to use proven rams. He’s
been adopting the use of AI on his very
best ewes.
He explains: 'The traits that make up the
terminal sire EBVs – such as muscle depth
and fat depth – are very heritable and
relatively quick to assess. However, with
the Lleyns, it’s mothering ability, that is
important. But this is not very heritable
and takes much longer to be evident.
So the accuracy of this EBV is less reliable
to start with.
‘I didn’t want the gamble of buying an
expensive ram, only for its EBV to fall.
So this year I’ve used frozen semen from
two rams – born in 2009 and 2011. They
have already sired plenty of offspring which
have gone on to lamb, making the EBV
more reliable.’
Last autumn Matt selected out his best 100
ewes based on their EBVs – those with good
scores for characteristics such as maternal
ability, muscling, and worm resistance. Then
from these he chose the best 50 for AI,
based on their ‘good structure’ – teeth, feet,
and teat placements. These traits are not
included in the EBV figure.
Success factors
Management factors on-farm play a critical
role in assuring good conception rates.
Matt’s ewes to be AI-ed are run as a
separate flock. In September they are flushed
to promote egg development, with the aim of
getting them ‘fit not fat’. After ovulation is
synchronised using intra-vaginal sponges,
insemination takes place on 1st October so
that lambs are born in the last week of
February, ahead of the rest of the flock.
Mike will visit the farm to AI the sheep
according to the treatment programme,
supported by a technician. Matt starts to
feed his ewes 7-10 days before they are to
be AI-ed. This helps them get used to being
handled. He explains: ‘They will come to
me, and do not need rounding up. So it’s
nice and quiet. No stress! They are used to
seeing humans and coming into the pens to
get the feed.’
After being AI-ed, ewes are returned to the
pen for hay and water, and go back to the
field once the effects of the anaesthetic
have worn off. ‘Then we leave them to
settle down and only view them from afar,’
says Matt. A sweeper ram is introduced ten
days later, and ewes are scanned before
Christmas.
The AI has been very successful. This year,
of the 50 ewes inseminated the lambing
rate was 86%. And of those that held, the
lambing percentage was 210%.
Mike says: 'I'm sure Matt's above average
results are in large part due to his attention
to detail and excellent short and long term
pre and post-AI management of the flock,
plus the provision of good on-farm facilities
for the AI day itself. He is also breeding at
a time of year when the fertility of the Lleyn
ewes is likely to be at its peak.'
Matt says: ‘The lambs from the AI are
already standing out in the flock – they are
structurally good, and liveweight figures are
also good so far.
‘AI is a lot less risk than buying a ram –
I can be sure I haven’t wasted money, nor
a year of time.’
The impact of using AI on the best ewes
has been clear; the flock’s maternal index
average was increasing by 5 units per year
from 2008-2014. However, after using the
frozen semen from the high EBV rams, the
average index jumped up 26 units in
one year.
AI – evaluating the option
Lambing rate is influenced by a number of
factors including type of semen used –
whether fresh or frozen, the breed, the year,
plus a host of farm factors. So Mike and Liz
advise that farmers interested in using
laparoscopic AI to improve flock genetics,
or as a management aid, should talk to
their vet. Also, if possible, they should go
and see the technique being used to
appreciate the factors that can influence
its success.
Matt is one of the original farmers who
pioneered the development of the Exlana,
a breed designed for extensive systems;
prolific ewes with high mothering instincts
capable of lambing unaided outdoors. It is
a wool-shedding sheep which develops a
rough winter coat making it suitable for
harsh climates.
This year 650 ewes lambed down outside
from 10th April with just Matt to look after
them. The lambing percentage was 170%.
A breed for extensive systems
Matt fully utilises the benefits of EID to improve
the performance of his Lleyn and Exlana flocks
Mike Glover carrying out laparoscopic AI