There are a lot of different rearing methods by farms in Australia, I know of a guy out in upper hunter valley who reared his pups in obstacle course paddock to teach them to use their eyes and brains to avoid obstacles. He put a lot of stuff like barrels, tyres, etc in the middle of paddock.
Some rearing farms (mine included) prefer to keep pups penned in at nights in 30m x 30m yards and let out daily for a couple of hours twice a day to free gallop in big paddocks. (more than 1 acre preferably, best is 10 acres or more, the famous Pringles reared them tough that way too, letting their pups run wild on huge acres.)

Other rearing farms keep pups in long straight runs, pups are never let out to free gallop around a huge paddock, so their skeletonal structure will be a lot more prone to calluses, deformity, overgrowth/undergrowth etc from constantly running up and down with other dogs in a long straight run, competing with their neighbours. Especially if the ground becomes hard and dry from the constant pounding, you'll find these pups at 12 months old with chronic wrist/metacarpal problems and 'dropped hips' etc.

One of my bitches was reared by a poor rearing farm in western sydney and was never let out to gallop, was kept permanently in a small yard along with her playmates and 20 other pups (at that time I had moved house and was working in a full time job, so couldn't get away to visit my bitch on the farm until she was 10 half months old. I had dropped her off there at 5mths old) So when I discovered the appalling conditions she had been in, I immediately grabbed her and took her home. But that 5 months already damaged her too much, she ended up with chronic wrist injuries, thin skeletonal frame (was well fed on bread and chicken though *rolling eyes*) dropped hips and overall her physical structure was just damaged to the keen eye. She broke in super fast but kept pulling up after each trial barely able to walk, so was only able to be worked every 2 weeks after her metacarpals and sore hips had recovered.

Never again will I send any of my pups out to be reared by anyone again, unless the establishment has been fully checked out in person first and with the internet these days you should be able to easily find out character references for each farm.
Back then I didn't have a computer or internet and most people didn't have computers too, that technology was still fairly new and only just starting to spread.
(And that was only 7 years ago lol lol)

All you have to do is post the name of a rearing farm on a forum, and ask members if they have used it and if anyone has anything nice or bad to say about it, and you'll have your answer (after sifting through some rubbish posts, don't forget there are jealous people in the game, so some of them may slander or say bad things about a certain farm even though they haven't been to that farm before).

cheers