hey mate and find some1 with a ground/ute finder and run your pup with them as often as possible on the ground and when your pup has the confidence to jump off the ute moving or stopped then chuck him on the back with the finder and he will pick it up from there if he is going to be any good
depends on the dog sometimes it will make him harder and more determined or could make him softer or not want anything to do with them at all
the best dog we ever had wouldnt hit any pig for 6 months after his flogging when he was still young but after the 6 months or so he was full flight into any pig he seen
some young dogs love and can be let hit bigger pigs seen 4 and a half month old pups hold a 50kg boar on its own with out any troubles but also does depends on the pup some will thrive on it some will just sit back and watch until they are ready let them hit what size pig they are willing to but dont egg them into it if they want to have a go they will if not leave it at that and let them watch and learn a bit more