Ewes are pregnant for 145-155 days. If we want to match our lambing season to the period of rapid grass growth in the spring, we need to breed them in October and early November. Today marked the 42nd day that the rams were with our ewes (which covers two estrus cycles), so today we separated the rams and ewes and trimmed everyone's feet.
In the past, we've had problems with footrot, a soil-borne bacterial infection. We've implemented a comprehensive vaccination, footbath and culling program that has resulted in far fewer problems. Today's foot-trimming work bore this out - we had very few infected ewes.
Unfortunately, the vaccine that we've been using has been discontinued - a common problem for sheep vaccines in a country with declining sheep production. We'll be able to vaccinate our sheep this fall, but I don't know what we'll do in the future.