I opened a new world on the snapshot on creative mode with cheats on, and tried to spawn animals for a farm, and they wouldn't spawn. I tried spawning them with and without cheats on in seperate worlds, as well as testing it with different resource packs. They won't spawn at all.
MC-137752
Animal spawn issues
Resolved
Awaiting Response
0
Is your render distance set to 3 or lower? There is a bug report for entities being invisible on low render distances (MC-137521), which may be your issue.