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American RBST Foundation Flock USA0001
Breeders of
British Registered Soay sheep


Artificial Insemination in Soay Sheep,
A Historic Project


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Gaerllwyd Norris  (S10949)
Sire of the first artificially inseminated Soay lamb ever born

In the spring of 2008 the first artificially inseminated Soay lambs in history were born in Oregon (USA) sired by rams from a farm in South Wales (UK). It was an eight year long project that provided the first new genetics since the original sheep were exported from England in 1990. The following is the story of how it came about; from a chance meeting on a trip to St. Kilda, to the collection of the semen in the UK, artificial insemination and finally lambs in the US. Over the course of this adventure we had two scares with cancer and borders between the two countries opened and closed as the UK was hit with one crisis after another, but ultimately our patience and determination were rewarded. I hope our experience will inspire others who are passionate about their own breed and will be informative to those who wish to use AI as tool for their own  programs.

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                                          Norris with ewes at Gaerllwyd Rare Flocks, Little Gaerllwyd  Wales,

                                                Part I  Wales

One of the most significant elements of the British (RBST) Soay Sheep project is that it included imported females, mitochondrial DNA. Since their export from England in 1990, the borders between Britain and both Canada and the USA have closed to the importation of all but semen, live sheep and embryos are no longer permitted; these ewes represented a last chance to import females of this breed. But even at that, the group only consisted of four ewes and two rams, an extremely small gene pool. From the time the flock left Canada for the US, a decade later, the idea of obtaining semen from the UK had become a priority. Not only would it have obvious long range genetic effects, but it would also add to phenotypic diversity which was limited by so few founder sheep. If possible sperm from carefully selected rams could make the flock more representative of the historic sheep living on Soay and Hirta. 

In the summer of 2000, I traveled to St. Kilda with a group of Soay enthusiasts from around the UK. On that trip I met Christine Williams from South Wales who I soon learned, owned the remnant of Professor Peter Jewell’s “Hirta” flock (brought to the mainland from St. Kilda in 1963). True to his wishes she had maintained as much of its diversity as possible.  Her flock contained polled and scurred ewes, scurred rams, self colored animals and sheep with white markings, one even with a white tuft on her head. These were all characteristics not seen in America. As cabin mates we quickly discovered we had a shared passion for these little Scottish sheep and Christine offered to help me obtain new genetics. Little did we imagine it would be eight years and several more trips to St. Kilda before our shared dream would be realized.  

The following summer I was given the name of Martin Dally of Supersire, Ltd. who specialized in semen sales and laparoscopic artificial insemination. This technique had been developed by Australian researchers in 1982. It revolutionized AI in sheep which for years had been considered impractical because of the ewe’s internal twisted and delicate anatomy, the difficulty of detecting estrus and of controlling their cycles. I finally met Martin at a workshop a year later and we discussed the possibility of getting Soay sperm into the US, he visited Christine in Wales in the spring of 2003 and encouraged us to try that autumn. Over several weeks in November two Gaerllwyd rams, Jock and Gulliver, were blood tested multiple times, as required by the USDA, on their farm by William's veterinarian in preparation for semen export to the US. When they passed their tests the boys were transported to a collection center where they were expected to stay for two weeks. They had been scheduled so late in the season however, that their semen was no longer viable enough for freezing and they were returned home with none collected.

Discouraged by the results of this first attempt, but determined not to give up Christine sent another ram “Cracker” as a trial to Malvern in autumn 2005 for collection for just the RBST archive. He produced successfully and encouraged by this result she and I agreed we would make a second export attempt in the autumn of 2006.

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                                    Gaerllwyd Norris (front) and Gaerllwyd Mustard at home in Wales                            
                                                                 summer 2008
                     

Gaerllwyd Norris #S10979 and Gaerllwyd Mustard #S10149 were chosen because of their heritage. The majority of ewes on St. Kilda are polled or scurred and Gaerllwyd Flocks is one of the very few farms in the UK that continues to breed for these traits.  While Norris and Mustard’s fathers were normal horned both of their mothers were polled and Mustard’s grandsire (dam’s side) was scurred. Further Norris’s great-grandfather had been born in Village Bay on Hirta and both had self color (solid color with no pattern) in their backgrounds. These two were also chosen because of their mild manner and even temperaments and were used to being handled, something Christine had learned were important for dealing with the stress of semen collection.

                                 
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                                           Mustard and Norris leave for Innovis November 2006

A few weeks before they were to leave both rams were put into small paddocks at home with a few "wives" to stimulate their desire to breed. Then on a late November afternoon they were driven to Innovis Breeding Solutions near Malvern, England an hour or so from the farm. There they settled into small immaculate stalls and were allowed to rest and adjust.
After a few days of recovery, the process began.

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                           the barn                                                preparing the artificial vagina
     Most of Innovis' business is collecting semen from high producing commercial breeds from local farmers, but they                                           also serve the RBST gene archive and overseas clients as well

At the other end of their barn was the collection area. A quiet teaser ewe had been brought into estrus with hormones and was stanchioned at the far end of the pen. Before the ram was brought to the ewe, a technician warmed the artificial vagina by filling an outer pocket with hot water so that the ram would not detect a difference and refuse to jump.

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                            The day we visited in the summer a commercial ram's semen was being collected

She patiently stood beside both animals and at the appropriate moment put the vagina in place to capture the sperm. Having done this repeatedly, she was very good at it. The ram was returned to his pen and the specimen (in a small cup that was in the bottom of the vagina) was immediately taken to a laboratory directly across from the barn.

                     
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                                                                 A diluted smear is rated for mobility

Under a microscope a smear was checked for mobility. To the untrained eye it appeared as a whirling kaleidoscope of fluid. A second diluted slide was prepared and with this the individual sperm became visible. Based on its mobility the semen was rated (1-5 5 being best) and if it passed it was placed in a small refrigerator for several hours to slowly cool.  Later that was transferred to a machine which loaded ¼ cc straws with a single dose for insemination. The date, a UK code, breed and RBST Combined Flock Book number were imprinted on the side of the straw for later identification.

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  Breed and RBST Combined Flock Book registration number S10979  Gaerllwyd Norris
      
            
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                                                      Note storage tank to the right of the loading machine

Once filled the straws were placed in the first of two freezers; the first to flash freeze and the second to deep freeze. When the temperature was low enough the straws were removed and hung inside a liquid nitrogen tank where they would be stored indefinitely until they were shipped or used.

After producing successfully for the RBST and NSP/NISP semen archive projects Norris and Mustard were moved to Innovis's export barn where they produced 98 and 52 straws respectively for America. (The USDA requires collection must be done in an export barn.) Their work complete the boys returned home in January. Both were blood tested twenty-one days later and when they passed the straws were approved for export to the States.

 

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                                                     British Soay ewes in Oregon


                                                     Part II  America

On July 3, 2007 my phone rang in Merlin.  “The semen is in Oregon”, the bubbly voice on the other end of the line said. Martin had taken delivery of the tank after it cleared customs the day before. Serving as my import broker, he had arranged shipping from Innovis in the UK, obtained all the necessary permits and dealt with all the red tape that anyone faces when dealing with the U.S. Department of Agriculture (USDA). I called Christine in Wales to give her the news. That night there was celebration on both sides of the pond. But we were still only half way there; none of our efforts would matter until we had lambs on the ground in the spring of 2008.

In late July I invited Steven Weaver to join the project. We shared import expenses and ideas on how to most wisely use the semen on our ewes. I had been told the ideal candidate for AI was between two and five years old, had lambed naturally and ideally had had twins. We went through pedigrees of both of our flocks, each selected ten ewes and two alternates and set the date with Martin for November 2, 2007 to do the surgery. The trick now was to synchronize all of ewes so they cycled at the same time on the same day. To do this we were given a very strict schedule. On October 17 our vet came to each of our farms and inserted sponges impregnated with progesterogens (a synthetic form of progesterone) in the vagina of each ewe. Over the course of sixteen days the hormone was absorbed through the vaginal wall into the ewe's blood stream which prevented her from coming into estrus naturally. When the sponges were removed on the sixteenth day progesterone levels dropped and estrus began. At that point each ewe was given an injection of PMS-G, a hormone used to induce ovulation, tightening the degree of synchronization so that all of the ewes came into estrus at the same time. Fifty-six hours later the insemination procedure began.

Twenty four hours prior to Martin’s arrival the ewes were taken off all feed and water as a full rumen and/or bladder could block his view of the uterus, making semen placement difficult and conception doubtful


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       Mustard and Norris wait in the tank                                             The first ewe is prepped
               Steve Werblow photo                                                           Steve Werblow photo
When he had everything ready in the barn the first ewe was placed on her back on a rolling laparoscopy cradle. In this position her belly was shaved, swabbed with Betadine, she was given an anesthetic and rolled over to Martin who took over. He tilted the cradle in its upright surgical position (a 40 degree angle) and made two small incisions, one for a manipulating probe used to bring the uterus into the proper position for insemination and one for the endoscope. A frozen straw of semen was removed from the tank to thaw in a water bath (98.6-100.4 F) for two or three minutes and once he could see the uterus was in the correct position, the probe was removed and replaced by the inseminating gun which contained the straw and a very small needle at the tip.  Viewing the two horns of the uterus through the scope he strategically placed the end of the gun on one and pushed the plunger which forced the inseminating needle to pierce the uterine wall and inject the semen. This was repeated with the second horn. The gun and probe were then removed, the incisions were stapled closed and the very hungry ewe was released to a stall for food and water. Eating within just a few minutes was critical so everyone carefully watched to make sure the ewe was eating before the second one was processed.  When all ten had been inseminated they were released to a paddock with food and water and kept isolated from the rest of the flock for forty-five days to ensure they settled.

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         Looking through the endoscope the inseminating needle at the bottom of the gun is strategically placed so
                that it punctures the uterine horn and the semen is injected directly into the lumen of the uterus.
                         Just two days after completing 8 weeks of radiation I was overwhelmed with joy.
                                                                                  Steve Werblow Photo

                                                    Three Months later

      AIthreemonthslater2.jpg (46908 bytes)  The suspense was killing me so when the vet came for my annual winter farm call she brought her ultrasound equipment to see if any of the ewes had taken. At least three, the three youngest, were pregnant. But it would be another two months before lambing and we had a final answer.  Success rates with AI in sheep can be quite low and no one had ever done this with Soay, we were making history. To our amazement 6 out of 10 ewes on both farms lambed and between them produced 22 lambs, including three sets of triplets, a rarity in Soay Sheep. A few weeks later, Christine’s lambs began to arrive in Wales, Mustard and Norris now had offspring on both sides of the Atlantic.

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  Artificially inseminated lambs in America * 2008 *  their naturally inseminated half siblings in Wales

Buoyed by our success, Christine and I decided we would try once more. Two new rams were sent to Innovis in the winter of 2008/9, but again too late in the breeding season and neither produced semen viable enough to survive freezing and thawing. We would have to wait another year. Determined to make this work Christine began lobbying Innovis in the spring of 2009 and with the help of Claire Barber of the RBST they were able to schedule a collection date earlier in the season. In mid November 2009 two new rams, Sandle Ash (S12364) and Gaerllwyd Quentin (S12380) were transported to Malvern and this time they both produced. Once again Martin Dally served as my import broker and took over all the necessary shipping arrangements.
 

 
Sandle Ash (S12364)


 
Gaerllwyd Quentin (S12380)

 

In June of 2010 I met Martin and his wife Joy at the Black Sheep Gathering in Eugene, Oregon and they greeted me with the news that my new semen had been delivered to their farm the day before. Standing in a sheep pen we pulled out our calendars and set the date for my third round of AI for November 14. (Because I had only had two of Mustard's lambs in the first round in 2007 I used him a second time in the fall of 2009).*

When I went to Wales in July 2010 Christine and I poured over pedigrees to choose which ewes would give us the best chances of pulling out self color or polling when crossed with Quentin and Ash; a project we anticipate will take some years and some careful breeding choices, including the use of artificial insemination on ewes that were themselves the result of AI. "Double Welsh" I am calling them.  I had been preparing for this for two years and had gathered a group of young ewes which I had bred the previous fall so as before all candidates would be between the ages of two and five and would have previously lambed naturally. 

Because we did not want to flood the flock with the new genetics we planned to inseminate only ten ewes, five with each ram, with a couple of spares  (knowing that not all would take) as we had done the first time. Of the thirteen ewes we treated ten lambed and they produced fifteen lambs, twelve of them ewes- which shocked even Martin. Because I had more of Quentin's semen than Ash's we chose to use two straws (doses) of Quentin and just one of Ash per ewe, but as it turned out that didn't seem to make any difference. Conception rates were almost identical for both and the resulting lambs were pretty much an even split between the two sires.  The "double Welsh" lambs do have a different look, one pair of twins in particular have very short faces, which I am hopeful will remain so as they mature. Wider, short faces, especially in rams is the norm on St. Kilda; they have lengthened and narrowed on the mainland and especially in the flock in America. Color variation was about the same as the previous two times, but declarations of coat color can't be made until the lambs are at least six months old.  With the exception of black the previous years lambs have not matured to the color variety I had hope to see, tans are still the same tan and most browns are the same browns as were here before.

Our plans for the future are twofold; continue using artificial insemination on AI ewes as they come of age (at about 30 months) to pull out the traits we believe have remained hidden in the current animals and to continue adding the genetic diversity that the four Welsh rams bring to the rest of the flock in a carefully measured manner. Ultimately the offspring of these animals will make their way onto the farms of other committed British Soay breeders strengthening the breed's chance of survival in America.

Determination and patience are probably the two most important requirements for the success of a  project such as this, with patience coming first. It seems you spend a lot of your time holding your breath. So many things can and do go wrong and having the semen collected is only the first hurdle. Animals can fail follow up blood tests when they had passed pre-collection ones, paper work can and is misplaced, the semen can be lost (thaw) to due to improper handling and disease crises can close the borders between countries. One year all exports were halted because of a foot and mouth outbreak in the UK and in the summer of 2007, just three weeks after our first tank had safely arrived blue tongue erupted in Britain. Had it been a month later, our shipment would have been tied up in the UK indefinitely.   

This has been (and continues to be) a very exciting and fulfilling project and I am most grateful to my friend Christine Williams in Wales. Without her commitment and resolve and the assistance of RBST staff members it never would have happened.



 Ash and Quentin's lambs with new friend "Katie" in Oregon April 2011
 

*Technical Note:
We have used two different delivery systems for progesterone and two different hormones to synchronize ovulation; 1. sponges /PMS-G and 2. CIDRs / PG600.  We had higher conceptions rates with the sponges and PMS-G which we have used twice.
                                                
                                                               

                                                        For  more information

on sales of foreign and domestic sheep semen and laparoscopic AI (artificial insemination) services. Visit  http://www.toprams.com/

on Soay Sheep and Gaerllwyd Flocks in Wales visit http://www.gaerllwyd.co.uk/

on the RBST National Genetic Archive
"A Rare Collection", The ARK, The magazine of the Rare Breeds Survival Trust, Autumn 2009

or visit their website at:
http://www.rbst.org.uk/regeneration/main

                                                           

                 

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