Unknownreported this bug
I already told about problem in ticket 1956 in discord, but mister Ashijin said it's better to create a ticket.
So the problem is about spawnrate of animals. In 1.3 MLibs it's broken for me. 1.2 MLibs works fine. So with 1.3 MLibs (dev version) no sheep, chicken, pigs, horses and some other animals just don't spawn by some reason. Also I noticed vanilla NPCs (villagers) also don't spawn. And if I spawn it by hand - it despawns, not sure it happens just overtime or after server restart, but all villages are empty.