My 3 year old MALE rottweiler does not seem to want to mate, why?
Can’t say I’ve heard that before!
Male dogs are very sensitive to a female in season and generally know exactly when the timing is right. If you’re trying to set up a mating, it could be that you’re misjudging the timing.
Other than that, I really can’t give any advice as it’s not something I have any experience with. If you have a show quality dog who is definitely worth reproducing but has no interest, then I can only recommend discussing it with your vet. As perhaps there’s some underlying health issue that isn’t visible.