We used to keep a smallish flock of Jacobs at the end of the last century (I love saying that

- late 1990s in fact).
We loved them, wonderful characters, beautiful animals, won us some prizes, taste delicious BUT we learned an awful lot about lambing from them, which is clearly in contrast to others' experience. I think we were given the wrong advice (we were newcomers to shepherding at the time). We were told that they absolutely had to be lambed indoors, and it was only when we observed that our Hebs, which were outdoors all year, including for lambing, had no problems at all, that we decided to try the Jacobs lambing outdoors too. The problem lambings reduced drastically. It could be too that where our flock was sourced from was a showing flock, so there would have been no selection against difficult lambing. They were also very large animals, too big really for Jacobs. It got so they were too big for us to handle, especially the 4 horned tup, so we sold the flock and concentrated on our Heb and fleece ventures and haven't looked back. I do miss the hordes of bouncy spotty lambs in spring.
I thought I should write this so Phillip Willie doesn't think they are always total perfection - no animal or breed can be that.