It depends. If the game you are after has been conditioned to associate human scent with danger, then odor control is critical. Factors like how well the species smells, how quickly it is able to escape from sensed danger, even the experience of the individual animal all come into play. Generally, if a species is intelligent, possesses a keen sense of smell, and is hunted regularly, it will be very aware of and shy about scents it associates with humans.