The breeder and stud jobs haven’t been implemented into this version yet. I have a full remake of those mapped out in the next Jobs Expanded update, I just haven’t had the chance to push that through yet due to trying to clean up the bugs from other features.
It is coming back soon and even better (I think, at least)! If it takes more than an update or two I’ll pop the old one back in as a temp measure, I just haven’t to try and prevent save game compatibility issues.