Just to add to the mutton pool, you also have old female sheeps that are no longer able to give birth. There's a chap in Cornwall adding value to these old ladies by giving them a bit of a retirement, getting them fit and healthy before slaughtering and dry aging them for some top UK restaurants. Check out The Cornwall Project - Matt Chatfield. Bit more about it here - https://www.scottgrummett.com/blog/the-cornwall-project. I am not affiliated, but would like to try it someday.