Hi Doganjo,
My situation is this, I train border collies to work sheep, the dogs are all usually fairly quiet, it happens when I take one of the young dogs out into the field to train, because I have to whistle, it starts the other youngsters off barking, if I then shout at them to be quiet, the dog I'm working thinks I am reprimanding it, sometimes it doesn't matter, but sometimes if the dog is of a sensitive nature it can really upset it. Plus the barking really winds me up, when I need to be calm to be able to train my dogs effectively. It has only become a problem because we have so many youngsters, when normally we would only have a couple to train at any one time.
I know what you mean about teaching them to bark on command, as I have a kelpie that I taught, but it is not something we would normally do with the collies.
Regards
Sue