Starting A New Pup Advice Please

[Dranny GLC 112]

I took my 6 month old whippet x greyhound ferreting today I kept him on the lead and let him watch 2 older lurchers which are good around the warrens and nets. As the day went on I started letting off a av a walk about sniffing he Evan had a good run after one bolted out of a un netted hole. After about 5 hours and we ad a load in the bag I got a live one out of a net took it to the middle the field we were ferreting and let it go and slipped the dog and got it after about 40 yard run, he dropped it and got it again and then retrieved back to hand, I was suited and the pup loved it. I wasn't too sure about doing it because of his age but I can't see how the odd slip will harm him.