mattand4

Oh, sorry. That is what I meant. But you should be able to use a spawn egg like this without being on the horse, like with any other mob. That is the issue.

But the issue was with using a spawn egg on a horse to produce a baby horse, not breeding. I have only been able to use a spawn egg in this way while riding the horse that I want to reproduce. It doesn't seem to work without being on the horse.

It seems to work while riding the horse.