Very funny and of course someone with your username would notice it! In case anyone is confused, the joke is that the sign is identifying the animals as gibbons when in fact it is the last name of the people who raised them and that is their award. Sometimes small petting farms like this can produce interesting animals. Zebras are often seen. A couple months ago I was at Fort Worth Stock Yards and their small petting corral had a nilgai! (Nilgai are feral in south Texas).
Its not a petting farm Its a large Agricultural show, probably one or two days long, where folk bring in all their top quality farm stock(domestics only) to be judged and then take them away again. Visitors do come and visit obviously and can touch some animals but thats not the main purpose.