They didn’t. It was the pig that came.
However, to attempt to more seriously answer your question, all I can find on the subject is this https://skeptics.stackexchange.com/questions/6611/do-pigs-have-30-minute-orgasms which appears to indicate that in most cases the 30 minute number is based on more than one emission. However, the source is a bit old and the links to university and government sites appear no longer valid.
acatlikecaligula t1_ivhdqbj wrote
Reply to I've been informed that a pig's orgasm is estimated to be around thirty minutes. However, I'm curious to know how they came to this conclusion. What's the science behind it? by hatinsidecat
They didn’t. It was the pig that came. However, to attempt to more seriously answer your question, all I can find on the subject is this https://skeptics.stackexchange.com/questions/6611/do-pigs-have-30-minute-orgasms which appears to indicate that in most cases the 30 minute number is based on more than one emission. However, the source is a bit old and the links to university and government sites appear no longer valid.