Apparently when it breaks we just buy a new one. [shrug]I prefer to use the one from Mazda. That is, once I reach 60,000 km or 80,000 km. I plan to ask those Mazda guys to remove the oil pan and filter, put it back with the new gasket and filter, then fill it with new oil.
The Owner's Manual does not say that it should be replaced. The dipstick is not even accessible. If ever you want to check its level, you'll have to remove a couple of things. It is like Mazda is telling you not to bother about the ATF.