Jimdog obviously has had some bad experience with poor rearing farms, however don't let that deter you from sending your pup to a rearing farm as ultimately this will lead to the pup gaining the best of life experience in handling fields on a racetrack.
All you need to do is do your homework re selecting the best rearing facility to place your pup in. Good rearing farms will do all the work required to turn your pup out lead broken, well handled and muscled up from being galloped with other dogs.

Also, breaking in should only be done by experienced people so if you intend to go that way yourself, make sure you follow the guidance/advice of a top breaker and don't ever rush the dog with too much trialing early, as it is so easy to stuff up a dog permanently if a mistake is made.

Don't be tempted by well meaning folks who have limited experience themselves in rearing, training or breaking in, offering you advice ;-) so if you know a good trainer already, then pick their brains out. Don't be afraid to ask them questions however silly you may think it is.

Good luck with whatever you do,

cheers
lilly