Purebred Ouessant sheep exist only in Europe, from which it is illegal to import live animals or embryos into the US. Hence, we have begun an upbreeding program starting with Shetland ewes and Ouessant semen imported from the UK.
Each succeeding generation of females will be inseminated with 100% Ouessant semen. So the filial generations will be 1/2 Ouessant, then 3/4ths, then 7/8ths, then 15/16ths, then 31/32nds, and so on. The first generation of lambs, 50% Shetland, 50% Ouessant, were born in April of 2009.
It took us a couple of years to import Ouessant semen from the UK — searching for an appropriate source flock, lengthy USDA/UK DEFRA negotiations on a semen collection protocol, quarantining of the rams, and a hoof and mouth outbreak. But finally in fall 2008 the semen from 2 rams made it to the US and in 2009, we were able to import semen from 2 more rams. We plan to eventually import semen from additional rams to ensure adequate genetic diversity.
We started with Shetland ewes as the initial mothers and had 2 crops of 50% Shetland/50% Ouessant lambs (Spring 2009, Spring 2010). The 2009 ewe lambs were inseminated in the fall of 2010 resulting in getting the 75% Ouessant lambs in spring 2011.
In fall 2009, the spring 2009 ewe lambs seemed too immature to breed. They didn’t respond to a teaser ram and not knowing how Ouessant genes would impact their size/growth, we couldn’t use the size of these lambs as a measure of maturity. (2/3rds of adult size is the rule of thumb for determining when you can breed a ewe lamb, but we didn’t know what their adult size would be.)
Although Ouessant sheep typically don’t breed until their second year, one of the 2009 ewe lambs unexpectedly delivered a lamb the next spring — we believe a 50/50 ram got into that field briefly. So we knew that at least sometimes the 50/50s are ready to be bred in their first year. Accordingly, in fall 2010, the 2010 ewe lambs were covered with a 50/50 ram lamb (which are definitely ready to breed at 5–6 months of age). This resulted in additional 50/50 lambs the next spring (2011).
We have followed that pattern in subsequent years of waiting until ewes are 1 1/2 years of age before inseminating them, but often using a ram with the younger ewe lambs. The main problem with using a ram is finding a suitable match.
Overall, we have been very lucky. The percentage of females has been significantly greater than the statistically expected 30% of lambs born. (See the numbers we expected for details.) In spite of losses to coyotes, mountain lions, disease, and unknown causes, we now have progressed to a flock of several dozen 75%−93% Ouessant sheep. See Our Current Sheep for more details.