Aman takes up farming but can't get his pigs to breed,

so he asked the farmer down the road for advice.

"you need to put them in your van,take them up the hill, them and bring them back"says the farmer

"if they're rolling in the hay the next day, they're pregnant.
if they're rolling in mud,they're not."

the next day, the man puts his pigs in the back of his van and follows the old farmer's advice.
to his dismay, the next morning they're rolling in mud - which means they are'nt pregnant. the same thing happens for three days.

on the fourth day, he can't bring himself to go through it again, so he asks his wife to look out the window.
"are they rolling in the mud?" he asks her.

"no," she replies.
"they're in the back of the van!"