Starting a race horse is like starting any horse. Work on stop, go, turning and backing. Try to teach them that no matter what happens they go FORWARD. Nothing worse than a half broke horse at the track who goes up, sideways or over backwards! You are dealing with young horses, who become extremely fit and are exposed to many scary things they have never seen before, so training them to have a somewhat predictible response to these things can help keep them safe when they go to the track. Work in the round pen with long lines and turning, do lots of ground driving. When you have a horse that can stop, go and turn accurately with reletive ease and consistency, then you can move on to galloping.
Galloping should ONLY be done on a track with proper footing and ONLY when the horse has mastered basic skills. There is nothing mroe dangerous than a horse running that can't be stopped! One so called trainer I know likes to go to the farm, grab them right out of the field, toss them in the trailer for the first time, take them to the track, throw an exercise saddle on them and have a rider sit on them while a groom walks the horse in circles in the stall. He does that for 3 days then sends them out to gallop!
I hope this goes with out saying, but this is not only extremely ignorant but potentially deadly to the horse and anyone else involved. HIs horses have a nasty habit of hitting the outside and inside rail numerous times in their first start due to fear and lack of proper training. There is no reason to rush a horse, any horse without atleast 90 days on them before going to a track is being rushed. If you rush a horse, you will break it down or get it hurt.
Avoid trying to teach a horse about the starting gate unless you have galloped and worked numerours horses and are licensed to do so. The consequences can be disasterous and at the very least you could teach the horse the wrong thing. I have seen way too many starting gate accidents with horses who were brought along properly, not all recover. One horse I knew got stuck under the gate, broke several bones in his face and would only walk in circles to the left after the accident.
There is no training a horse to be TB, they either are a Thoroughbred or they are not. Just because a horse has parents that could route doesn't mean the ofspring will route, they may be sprinters. And if they are going to run a route, they all start with shorter races. You can't get a horse properly fit for a mile+ race for its first race, and even if you could, that's a long time to be focused on something they have never done for a baby.
You are not required by any state to have a license to train a horse to be a racehorse, you do however have to have a license to RACE said horse in your name, either as owner or trainer.
If you are uncomfortable with any horse as a yearling and cannot teach them proper ground manners, they you have no business trying to train one for anything, especially racing! These horses (if bred for it) are extremely athletic and when you add grain and exercise, extremely strong. If you cannot handle them, stay away for your own and their safety. Racing is not for wimps or the faint of heart, it takes commitment and nerve and alot of hard work. There is no such thing as making a quick buck on horse racing unless you are a very top of the line pinhooker and even then it takes months and they can still lose! Breeding a horse for any reason, especially racing is NOT a way to make money unless you REALLY know what you are doing! Ask any one of the top farms in Kentucky, it takes money to make money and even then there is no guarantee.
Alfalfa does not give a horse too much energy. How do you think a professional athlete gets its strength to perform? Grass hay does not cut it, they need MUCH more in the way of nutrition. I feed alfalfa twice daily, more for those who needed it along with a variety of supplements that are tailored to each particular horse. For example, we fed tagamet and other stomach remedies to those who were nervous and tended to have ulcers. We never gave steroids, but did to one horse who barely ate in an attempt to stimulate his appetite and it worked for him. As a base feed I prefer Omolene in the red bag, it is a good cover all bases feed, but we still added supplements like MSM, etc. Older horses with mroe mileage get joint supplements and possibly injections if needed to help lubricate their joints. Young horses get only a very small amount of grain while in the beginning of their training, and none when in the breaking process, they don't need it until they are actually BURNING it daily. They don't do this until they are galloping consistently at the track, meaning they are galloping in pairs or alone and know what they are doing. If they are still balking and looking around, they are too green and are just going to become more of a handful and feeding them anything besides hay is a waste of food and money.
Please, PLEASE anyone considering getting a young unbroke horse for any reason, especially racing, RECONSIDER! One of my childhood trainers used to always say, "There are no bad horses, only bad riders/owners/handlers". Realize ANYTHING a horse does is a DIRECT reflection of what YOU are doing with them. Their own individual personality comes into play but if they are mean, aggressive, unmannered or get injured it is ALWAYS YOUR FAULT. Please do not take this lightly and do not try to train a racehorse without ATLEAST working as a groom at a track for a year, and that's if you already have extensive experience with owning and riding horses. Before I trained my own I had ridden and shown english, western, hunter/jumper/eventers. I started galloping horses on the weekend at a farm and did that for a year before I galloped at a track. Don't go into this unprepared, get a job at a race track and learn first or you will find yourself in way over your head.