Hi, I've placed my spawner that I got with SkyKing and used "/spawner cow" on it and was told that it had changed to cow.

Since then it has spun, is still spinning, but hasn't yet spawned anything.

There's plenty of room around it, nothing for 30 blocks below it as I want the cows to fall and die (I want leather).

I've seen that this isn't an unusual question, but I couldn't find any definitive help through search.

Thanks in advance

 

Passive mob spawners can only spawn mobs on grass blocks. try adding grass blocks around your spawner.
To make it auto kill the cow, try making a row of grass blocks, add string which activates a piston that then pushes the cow down to their death/into lava

 

ah, well, that would explain it, thanks, I can work with that.

 

Yes, it's all good now. Thanks.