New Dam's can and are usually more cranky and aggressive after they have their foals. In my experience, you need to respect her. This is her foal, and if you still want her to trust you you need to stop or you will end up getting seriously hurt. I had a mare that did what you were saying she bit me once out in the pasture but a negative reaction + a negative reaction only makes the animal MORE aggressive!
Humans are predators and horses are prey animals, they see us as predators so being negative won't help your situation!
And to be honest, if I were a new mom and you were my owner...and I was your horse. I probably would have killed you by now. You need to think like your mare for a second. How would you feel about having a foal and trying to protect it?
Obviously, you don't have the relationship with your horse that you thought you did. Because what I have learned is that a mare with and/or in foal is only nice/sweet to those who it has a true and strong relationship with and won't let anyone else near the pasture.
Just my 2 cents worth, sorry to sound rude or anything like that. I don't mean to I'm just getting to my point, and saying it straight.
Ditto. I would try to give her space and reason with her a bit. She is just a protective mom.
I had a dog once that had puppies, she got pretty protective over them. The first time my dad reached for one she gave a growl and grabbed his arm (Not hard at all, very gentle actually. She was warning him though. If he would have kept at it though, I'm sure she would have bit him. We didn't have that great of a bond with her yet -long story). Anyways, over the course of a few days we were very calm and let her know that we were not going to harm her puppies. We'd go around her, just sit a little bit off. If she seemed to get nervous or tense we'd just talk to her (but didn't reprimand her or push the issue). Eventually she saw us as okay and I was playing with the pups in no time. I can't imagine what would have happened if my dad would have thumped the dog for grabbing him though -VERY ugly!!
I can see where you would be frustrated and kind of hurt. Owning her for so long and getting this kind of reaction. My suggestion would be to come off as calm and try to convey the message you aren't there to harm the new foal. Try to avoid situations where you would spark her to bite or act out aggressively. I'm guessing this is her first foal, so I'm sure she's trying to adjust. One tip --never
go between her and the foal right now. Not until you have established 100% trust with your mare. When my mare had her foal, even though my mare handled it VERY well (wasn't aggressive with us at all) I still didn't step between her and the foal for a couple weeks. I didn't want her to feel threatened in any way.
If she does bite you, I would give her a light reprimand. Maybe a slight tap on the shoulder or nose. I would avoid any explosive emotions right now though. It would be best, as I said early, to try and avoid that kind of situation. When she is sweet, praise her for it and let her know that you only mean well. Maybe, try not to show to much interest in the foal so that she doesn't have to feel as protective.
With your guys history, I think if you take baby steps, and treat her as non-threatening as possible with a week or two --you guys will have everything sorted out.
Best of luck to you! Keep us updated and I would love to see pictures (as I'm sure others would too!)