Why does everyone say no bit with a young horse? Please explain as I come from a different background and I see no problem with introducing a bit at this age...
I had a shetland/arab x that was extremely mouthy as a weanling. He was already gelded so studdyness was ruled out. A mini bit put on him from a "bit hanger" (not a real bridle - since didn't have any that would fit his TINY head!) worked real well for the mouthiness. Later, he was one of the easiest ponies to ground drive and back that I've ever had.
I'm currently working with several yearlings and 2 yr olds. At feeding time, while they are tied at their feed buckets, I work with their heads and ears and then slip a headstall w/ a browband and throatlatch and bit on them. If I had 2 more right now (working on that one - both the headstalls which I'm making & purchasing the bits) - all of my youngsters over 1 yr of age would be getting acclimated to a bit. Then when we do leading and loading in the trailer lessons - they are experiencing the feel of the halter along with the bit/headstall.
If this filly is already used to going on "round-a-bouts" and doing things - I don't see a problem at all with introducing a bit while doing these things. For that matter, go on and then start bitting her up a little or actually teach her to give to your hands from the bit. I've seen plenty of yearlings started this way. Then when you do your round-a-bouts, graduate to ground driving her and getting her used to you following rather than leading. I used to have many pictures of yearling Welsh, Hafflingers & Fjords being grounddriven out on trails - navigating grass, hills, ditches and water and learning to move forward thru whatever environment they are introduced to.
I didn't realize that a pony shouldn't have "heavy" weight when pulling - so when introduced to training w/ a driving sled and getting our young filly going - we just naturally moved from pulling a drag to actually hitching and driving (but it was over a 6 month time period). Honestly - we spent more time ground driving that filly than I've had trainers suggest i do now. AND I'm glad that I learned to start them slower - and when they were younger... That filly was pulling a light weight (& compared to the mini sized Jerald - IT"S LIGHT!) sulky cart meant to be pulled by a much larger Hackney pony w/ both myself and our 4 yr old daughter. AS a full 2 yr old she was started under saddle and wasn't driven after that for the next two years at all. Then I started leasing her out and it would be 10 years before I got her back to put into our own program. Last spring 2010 was the first time she was driven since 1998 as a long yearling! She had picked up a lot of bad habits from little riders - we are working on those...
Back to the young horse - as my "babies" get used to wearing bits - and giving to a rein/line, I have every intention of starting to line drive them. Will I attach the lines to a halter first - well, that might just depend on the pony... Some might be closer to 3 yrs while others will be only about a yr old... Then will go to full ground driving - around my property, off our property, taken to other riding areas where I can safely ground drive some trails. They will be getting used to ground driving - by themselves, with at least one other pony and also standing at the horse trailer - hopefully quietly. Last year, GG went every week to my driving lessons w/ her dam and aunt. She was only 3 weeks old during our first lesson - she was turned loose to run for part of it (she wasn't trained to stand tied yet) and then attached to her dam when she started consistently getting in the way... Those were probably the best lessons I could have done with her! Wish I'd done more of that with my driving ponies this year (but 3 of the foals - all stud colts - are out of mares not even trained to drive yet). Instead, I was concentrating on getting Bell/Bit going as a team. I still have time, later, to drive a finished pony w/ a foal alongside (once I have the foals all leading better, LOL). GG is used to going across pavement (quietly), hearing a wagon rattle, seeing and hearing dragging equipment (a board, a chainlink pasture drag, a tire, a heavy board drag) on different ground surfaces. And responds to walk, walk-on, ter-rot & WHOA. She turned a yr old on June 10, and is now one of the ponies wearing a bit. She was a little surprised when I started her first work alone lesson in lounging a couple of weeks ago but took to it easily once she understood what was wanted - no crazy haring around. Just a different way of doing things she'd already been doing - and doing it now alone... She's not working hard, nor long - nor am I expecting her to.
Many farm horses are "started" by following their dams in the field, then being attached to them. As yearlings they are introduced to equipment and can still go out with their dams - though they aren't hooked into the arrangement for pulling. Not every trainer/farmer does this of course. I watched yesterday as two older mules were worked that have had some problems - they are draft xs and HUGE... They would have benefitted from this kind of learning early in their lives. LOL. Trust me, they would have been easier to work with if they'd had more handling as youngstock.
I guess my main ? is why not put a bridle/bit on and then teach them to ground drive at one year of age? something else to do, something else to introduce them to & gives them the ever important job and chance to bond with the driver. Also, since it might be understood that the youngster isn't mature enough to pull weight - there's no pressure to get on with that & you can develop a repoir w/ your youngster much earlier at a slower, enjoyable pace.
I do have to admit - the first time I saw someone show up with a weanling w/ a saddle on - my sensiblities were offended... But truly no differnt and I learned that that trainer/handler wasn't putting riders on the weanlings - just introducing them to tiheir future "job" - at an early age. They quietly & quickly learned that a saddle blanket and saddle w/ flopping stirrups and girth were just another part of their immense environment. They also were turned out into much larger pastures than I've ever had access to for many months and then later pulled back in as yearlings and ground driven, in a similar way. Then turned out again until they were old enought to graduate to pulling objects... And then brought back up as long 2s to start riding. Those were the some of the most well mannered, well rounded riding horses I've ever seen!