In French, this breed is called "Bouvier bernois", suggesting it's been bred at least in part as a cattle dog. So they're a livestock guardian dog of sorts. That doesn't suggest much of a well-developed prey instinct. (Our own "doodle" is a quarter Bernese and another quarter Maremma - another livestock guardian dog - and such limited prey instincts as she has presumably come from her poodle father...)
In French, this breed is called "Bouvier bernois", suggesting it's been bred at least in part as a cattle dog. So they're a livestock guardian dog of sorts. That doesn't suggest much of a well-developed prey instinct.
(Our own "doodle" is a quarter Bernese and another quarter Maremma - another livestock guardian dog - and such limited prey instincts as she has presumably come from her poodle father...)