So I’m only keep sheep as a hobby (about 50). 20 are earlier lambers. Finished lambing them yesterday. All have lambed previously and the same tup was used and I didn’t have this problem last year. all singles lambed fine. I had 5 twins. all of them birthed themselves but 1 lamb was alive and the other was dead. The dead ones had been dead in them for a while as they were always smaller than the live one and they had also started to rot and go smelly. any idea what could cause this?