Well I have found when breeding your own stock,watching and in my case ,helping with the birth,a very strong bond has been formed.
But ,as already been said,it's hard work ,time consuming and very expensive,but also very rewarding.
I was lucky, my bitch only had 2 pups, but it was so hard to let the other pup go, even though I knew he'd got a great home,because I/we had become attached to both of them.