At 5 days it's not going to be the pork (unless it's not been stored properly chilled).
Feeding is unlikely to affect it either - only big quantities of something like turnip, cauliflour etc would maybe give a slight smell.
Were the boars intact and had they been running with the gilt? My gut feeling is that it's a boar that's been cured - curing can amplify the taint (obviously if they're castrated it'll not be an issue).
It may just be this particular cure?
Because I'm one of those who can smell taint it puts me off eating it - but I'm told there's no taste of it.
Have you soaked the ham overnight in clean water? If you plan on roasting it, I'd do that and see if it helps (if you're boiling it, it's not an issue the salts will come out then). Then I'd slice a bit off, cook it and see how it tastes