Would love to hear your experiences.
I’m considering breeding my mare at some point. She’s practically perfect in every way - gorgeous mover, super brave, no spook, easy to ride, comfy, and competitive at top shows. Her only drawback is that she doesn’t like other horses near her. She pins her ears, snakes her neck, and makes mean faces if horses get in her bubble.
The behavior is mildly annoying, but not something that would concern me if she passed this behavior to her foal.
I can imagine this behavior might become more intense if she were protective of her foal.