A farmer had 5 female pigs and times were getting tough, so he went to the country fair to sell his pigs. At the fair, he came across a farmer who had 5 male pigs. After talking a bit, they decided to mate the pigs and split everything 50/50. The two farmers lived 60 miles away from each other so they agreed to each drive 30 miles, and find a field to mate their pigs. The first morning, the farmer with the female pigs got up at 5:00 am, loaded the pigs into the family station wagon, which was the only vehicle he had left, and drove the 30 miles.
While the pigs were going at it, he asked the other farmer, "How will I know if they're pregnant?"
The other farmer replied, "If they're in the grass grazing in the morning, then they're pregnant, if they're in the mud, then they're not.
The next morning they were rolling in the mud so he hosed them down, loaded them again into the family station wagon and proceeded to try again. The following morning, MUD again!
This continued all week until one morning the farmer was so tired that he couldn't get out of bed. He called to his wife and and said, "Honey, look outside the and tell me if the pigs are in the mud or in the field."
Neither one," yelled his wife, "They're in the station wagon and one of them is beeping the horn."