Where did the term "hog heaven" come from? I have heard that it has to do with breeding pigs, that when the hog reaches sexual bliss, it lasts for several minutes. Can you clarify? My brother and sister-in-law don't believe me.
-- Looking for Hog Heaven in Poway
And well they might. But I'm sure they didn't offer an alternative explanation. Once again the great thinkers in wordville let us down. There's no official explanation for the origin of the term. The Merriam Webster folks say it's American and the first print reference dates to 1945. But in 1871 the founders of the town that would become Moscow, Idaho, named their patch of land Hog Heaven, Idaho. So the concept of porcine euphoria is older than '45. It's likely just another of those rhyming or repeat-letter phrases that we like so well (the bee's knees, f'rinstance).
We also need to rid you of the bad animal husbandry facts that make your explanation doubly doubtful. There isn't any extraordinary sexual bliss in the pigpen. Not even pigpens in Poway. That kind of stuff seems to be reserved for humans and our close relatives. The bogus story might come from the unusual design of pigs' equipment and the necessity of getting both sets of said equipment working in synch. The boar's penis is shaped something like a corkscrew. So's the sow's vagina. All the twirly parts have to match up before they can make little pigs. This can take a little longer than usual with some other animals. So it's the early innings that might be prolonged, not the ninth. But if you imagine some hayseed watching pigs do it, I suppose the phrase "hog heaven" might occur to him. But that's what's called a folk etymology. And the world is full of folk who'll believe it.