Someone would have to show you how and when to use a chain shank. If used incorrectly, it can create an awful, awful mess - even more rearing, running backwards.
Unlike many people, I could care less how an animal acts at feeding time, as far as when they are loose, what they do is their business if they are not touching me. I could care less what faces they make or if they lay their ears, as long as they don't land a bite or kick on me. They're allowed to have an opinion, as far as I'm concerned. Too, if I picked on the horse every time it moved its ears or made a face, it would be a nervous wreck, and just cause more stress, which is where the behavior usually comes from - stress related to management issues. I want to punish them only for important things, they will get plenty of corrections for just those major things when young.
If they are actually connecting - biting or kicking me, I have to punish them, but I'd take a serious look at how my facility is arranged - what about it is putting me in that position.
The minute they get to my place (or usually, if they've been trained at all, before they get to me), they are trained to go stand on the other side of the stall while I put feed in his bucket(or feed hay). They can stand over there and make a face and mutter to themselves all they want. A few careful flicks of the whip will get the horse 'aligned' on the wall. All young horses should be taught that, but if they're all loose outside, it's pretty impossible to train and control any of them.
Maybe you haven't done that, or maybe your setup at your farm encourages a lot of hysterics at feed time.
If you are having a problem with a youngster, don't get upset. Either your facility needs a little re-arranging or you haven't taught them something they need to know. Young horses are a 'blank slate', and they do what they are taught to do - for better or worse. We're constantly teaching horses each time we're around them, whether we intend it or not.
If you're walking into the stall afraid of them, hesitating, moving backward when they move toward you, they do what they would do in a herd, chase the 'little horse' (you) off from their food. That's just nature. Walk in, put them over on the wall(you can use a command right as you're coming in, and then flick the whip at shoulder and hip to align them on the wall, the command is usually 'get over', or 'stand up'), dump the feed, walk out. Act very confident, and your motions and hence 'body language' are very different. Move toward the horse, and get him to move away from you.
They usually have a fit if they have to compete for food - and later, have hysterics even in a stall because they've gotten in the habit of doing so...or because the stall is too open to other horses and they perceive a threat. The trick for me is not all about punishing them if they're getting nutty at feeding time, it's about arranging my facility so feeding time just is a quieter time...usually then one needs to do very little to be safe at feeding, just a wee bit of 'tweaking' is all that's needed.
Too, if fed only once a day, horses tend to get more antsy. Sinmply put, they're hungrier. Feeding small meals 3 or 4 times a day makes for more relaxed horses.
Having a visual barrier between horses(it can be as simple as a large piece of burlap), tieing them up far apart for feeding, or putting them in their stalls, makes feeding time a lot more peaceful. Walking around in a group of loose horses dumping feed on the ground is a really good way to get kicked or stepped on.
Of course, it's also entirely possible that due to overfeeding and underworking, the filly is restless and has too much energy. If she's not in a 'program' of being worked and handled five days a week and is getting a bunch of alfalfa, grain and supplements, she's going to be acting like a git. From your descriptions, you do nothing with her for long stretches of time, and then give her a lengthy session - one was four hours.
You're going to run into a lot of trouble trying to handle young horses that way. That kind of thing is pretty much doomed to fail. Trust me on this - I've done both and seen the difference.
Everything has to be about a routine. Every single day, you get your horse in the same way, take him to the same place in the barn, and do the same things, in order, work on the same things - every single time. The horse learns the routine and expects it and behaves well.
Being in a small pasture or paddock can also lead to restlessness and poor behavior. Many farms are too small for young horses, who need a place where they can run with other horses the same age, play-fight, and move around...not working, not something structured - just taking a rest and then playing when they feel the need to move.
Please...never work a 2 year old horse for four hours straight. Fifteen minutes should be the limit. You can take them out a couple times a day, but working them for four hours straight - ON ANYTHING - grooming, loading, leading - no. They're too mentally immature for that. It causes a lot of psychological stress and more poor behavior. 'Teach 'em and leave 'em alone'.
In other words, it isn't just about a trainer being there. A trainer comes say, once a week, or every two weeks, or once a month. You need to set aside time, every day, and follow that routine, and do - well, it really is a lot of work. With the trainer's guidance, you'll know more what to do - but making a well behaved young horse...it really is about the owner setting aside that time every day and doing a lot of work.
