Securing Whitebred Shorthorn Genetics for the Future
A report by Ruth Dalton, Rare Breeds Survival Trust Field Officer (North)
Earlier this year, Helen and Philip
Marginson of the Northwood herd of Whitebred Shorthorns contacted
me to ask whether RBST would be interested in flushing one
of their cows, Lochdochart Snowfall 15th, for embryos.
Although embryo transfer in cattle is a technique that has
been carried out for decades, it is something that RBST has
only just started to employ, as previously the costs have made
semen collection from bulls a much more viable option.
Although some of the semen we collect is made available for
sale, the primary purpose is to create an archive of genetic
material that would be available in case of dire emergency
in the future. To this end, we always maintain a stock of 90
straws that are not sold or used for any other purpose. However,
this does only represent part of the genetic material of an
animal, some of which is only held in female DNA, so we have
been investigating the possibilities of a large fund raising
effort to extend our collections to embryos as well as semen.
Snowfall 15th is one of the first cows we have
flushed in this way, and we were very grateful to the Marginsons
for offering her, and fortunate to be able to use a little
funding remaining from the Prince of Wales, who kindly donated
money to allow us to purchase the RBST herds of Whitebreds
at Dumfries House and in West Wales.
Helen and Philip prepared the cow using a series of hormone
injections, which caused the cow to "super-ovulate",
she was then inseminated at a precise time in the cycle, as
with normal AI, but we used three different AI bulls - Corrie
Riever, Longley Talisman and Spoutbank Gay Gordon. The bulls
were chosen as they were considered to be the best genetic
match to the cow, and we used three bulls because this has
been shown to increase the success rate owing to a phenomenon
known as “sperm competition”. Five days after insemination,
the embryos were flushed out of the cow by gently washing the
uterus with a saline solution. They were then frozen for storage.
We were lucky to have the experience of the specialist ET team
at veterinary practice Lambert, Leonard and May, who were able
to make the journey to Lancashire to carry out this final part
of the process.
Helen and I were at the Great Yorkshire Show with one of their
other cows, Northwood Elizabeth, who was star of the show on
the RBST stand, so there was an anxious wait as we had left
Philip “holding the baby” at home. It was a great
relief and a real milestone for RBST’s new embryo “bank” when
Philip rang to tell us that 5 embryos had been collected of
high enough quality for freezing. RBST is hugely indebted to
the Marginsons for the time and effort they put in to making
this possible, and we are delighted to have some Whitebred
Shorthorn embryos safely in storage in case they should ever
be needed in the future.