I always find it interesting how humans and pigs seem more related than monkeys when it comes to our skin and other organs. I would expect a monkey liver would be a more obvious replacement.
Using monkeys for transplantation is also completely impractical because they can’t be bred as fast as pigs which have shorter gestation periods and larger litters. Since there is already a huge industry revolving around pigs, its much simpler to breed them specifically for xenotransplantion
Other horses really don't mind fences. Our neighbors got their SUV stuck driving around one Saturday night and then got a truck stuck trying to get it out (forgot the law of physics that says you should always tow a vehicle downhill if you at all can) and they came over looking for help. We took our tractor out there and cut a hole in the fence to get in to get them unstuck.
They never patched the hole but the horses they had stayed in for about a year and half until they discovered we had horses too after which they would come around to see our horses whenever they could and they learned they could just jump over the fence and come up to our place on the road.
They didn't have the right equipment to hitch them so I would take the horses to their place and tie them up with haystrings and such and leave angry messages on the answering machine.
At one point I changed my tack and decided to leave a nice message on their answering machine requesting that they pick up their horse. I offered them a pail of grain which would have let them catch the horse easily but instead they chased the horse around the outside of our electric fence which is bordered by hedgerows on both sides and after they got around to the other side I caught the horse immediately with the grain and handed it to them. After that they sold it right away.
That's one reason why their feces are so offensive compared to real herbivores like horses or cows or carnivores like cats and dogs.