I wonder if some of you who have actually had both breeds could sort of compare and contrast them. Regarding temperments, typical personalities, strong or weak points. We have a dozen cows and 60 head of ewes and "work" them with a small female border collie. She isn't professionally trained, but between her natural instinct, the obedience training I gave her, and her close oberservation of our previous stock dog she learned to do a good job for us. She is getting a few years on her I would like to get another dog for her to train---and to give her a little back up with some of the cows. She is very good for her size (30 lbs), but sometimes a little timid around the cows when they get "on the prod" a little bit. There seem to be quite a few border collies and Australian shepherds available in this area. Advertised as "ranch raised" and "from working parents." Are AS as good with sheep as a BC? I don't want a biter. Is an AS smart in the same way that a BC is? Do they tend to be a bit more aggressive? I know I don't want a dog as aggressive as a Heeler around the sheep and goats. I sure would appreciate any input you people who have used both types of dogs on livestock can give me.