I love watching herd dynamics be it goats, cows, horses or a flock of hens.
I don't breed(except a few chickens), have only had one cow but I could watch my small herd of horses interact all day.
Used to have a QH gelding who was gelded at 5 or 6 yrs old, he remained kinda studly well into advanced old age. Pretty much anything except produce a foal. When a predator would approach his band of mares the pony would choose direction of travel and old King would bring up the rear making sure the fillies would continue out of harms way. Really the pony mare was in charge but he was the one that made a lot of show and bluster so you noticed him more. A late gelded donkey would also drop back and do a rather in-depth analysis of the situation. Sometimes he would stay and back up the QH, sometimes he would leave town with the mares (bears). If it was a coyote the donkey would command the attack. Either way the QH almost alway fell into the expendable position. Without him knowing it the donk would set him up as a distraction and swing in for what he meant to be a kill. Sometimes the donkey would intentionally run a young coyote into the electric fence. The donkey would obviously be smiling as the young canine went screaming back into the woods.
Since the donkey passed I've pretty much given up trying to keep goats and chickens. I had a goat taken out by coyotes a couple of years ago. Was a big dairy buck with huge recurving horns but very old. I could see where the QH actually attempted a rescue by the tracks in the mud and torn up grass but he was too late. Knowing old King it probably took him too long to work up real courage and dive in.
Not mare and foal but my pony mare raised a goat. Bambi was just barely weaned when I got her and the pony took to caring for her. Would groom and protect her like it was her own. I still had to do a little bottle feeding but the pony did the rest. Goat actually had an alpha position in my little horse herd because of it when she grew up. 2nd in command a nubian goat. That goat in turn raised a 4 day old jersey calf I was given. Sammy Sirloin didn't stick around long enough for an official position in the pack but I often wonder what would have happened. I actually sold him to somebody down the road. Knew I wouldn't have been able to use him for the original intended purpose. Plus he was still trying to nurse on the goat who had 2 kids of her own and he was getting way too big too fast. No more cows. Learned that real fast.