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WORKING
TOGETHER
FOR A HEALTHIER FUTURE...
5
LIVESTOCK MATTERS
SHEEP FERT I L I TY
The use of artificial insemination in sheep flocks has several benefits: it
allows semen from rams of high genetic potential to be used without
commitment to the purchase of a ram; it allows one ram to be shared by
smaller flock owners; and it can be used as a management tool, to
concentrate the lambing period.
Veterinary surgeons
Mike Glover and
Liz Nabb
XLVets practice
Torch Farm and Equine
MIKE GLOVER AND LIZ NABB, TORCH FARM AND EQUINE
The benefits that AI can
bring to sheep flocks
South West Sheep Breeding Services provides
AI and embryo transfer for sheep farmers,
and is part of XLVets Torch Farm and Equine.
Last season, over 1,000 laparoscopic
inseminations were carried out. Here, vets
Mike Glover and Liz Nabb outline the
potential for farmers.
Breeding services
SWSBS was set up in 1990 by Mike and
embryologist Ronnie Lock, and is now
led by Liz with support from Mike and
Ronnie, and technicians Jemma Morris
and Kate South.
Liz explains ‘The service provides an
opportunity for small flocks to use frozen
semen from a good ram. This helps them
avoid inbreeding, and rams can also be
shared between flock owners without the
risk of spreading disease.
‘For larger flocks, using AI can enable one
ram to cover a large flock in a short time,
and keep lambing periods concentrated.
‘Fortunately different breeds want to lamb
down at different times, so we get a spread
of work! The main breeding season is July
to September, plus Dorset sheep flocks will
be inseminated in April.
‘We can hold up to 20 ewes here at our
South Molton practice, but travel out to
flocks for larger numbers.’
Frozen semen is used in around two-thirds of
cases, with the remainder using fresh.
In a survey carried out by SWSBS on the
lambing rates (% of ewes AI-ed that lambed),
77% of 4,100 ewes lambed following
insemination with fresh semen, and frozen
semen gave a 68% lambing rate (from
7,544 ewes).
Mike adds: ‘Breed and timing in the season
also affect the results. We see slightly better
results in Charollais and Suffolk ewes,
whereas February-lambing Texels can have
poorer lambing rates.’
Flock improvement
Sheep farmer Matt Geen has been using
AI for the past two years to introduce
new genetics into his 400-ewe pedigree
Lleyn flock.
Mike Glover and Liz Nabb with Matt Geen