I have heard people say that a working Border Collie dog should absolutely not be raised as a pet. I disagree with the statement because I have personally raised a lot of Border Collie puppies in my backyard that turned out to be very nice working dogs. I do believe that how a puppy is raised has a huge impact on how trainable it will be. I believe that Border Collies are capable of discerning work from non-work activities. Red Oliver once told me that dogs associate many commands as either "on stock" or "not on stock". An example is a dog that is taught to lie down only while on stock. Some of those dogs will not immediately understand that command when livestock isn't present. They can certainly be taught it and/or forced to comply, but they often don't necessarily associate the command with an action at first. I know some folks will disagree with this example, but I have seen it a lot of times and over the years and always think of Red when I do.
What I do believe is important is how a puppy is raised. An important factor relates to the fact that a dog must be obedient during training. If we raise a puppy with a lack of consequences for obedience, and then expect them to be cooperative when we start training, we have set the dog up for failure. A dog also needs to learn that they way something is said is important. Border Collies are very good at learning that when something is said in a low growling voice, that it is a correction. This is important during training. Dogs learn to take correction by voice and if biddable, will work to avoid those corrections at all costs. That is a major underpinning of training a Border Collie dog.
Jimmy Walker authored an article titled "Raising Your Puppy Right" that was published on Cowdogworld.com on June 15th of 2009. This article does a wonderful job of summarizing things to keep in mind when raising a puppy that you or someone else hope to train once it's mature. Each time I read it, I am reminded of something that I am not doing as well as I could with puppies in my kennel. I have sent it to a lot of people of the years and I hope others have found it as useful as I do.
A working dog is a true companion. Many folks spend more hours with their working dog than they do with humans. To treat them as anything less than a respected member of the team would be a shame. But just like any member of a well functioning team, they need to know their role and play it.