Barnyard Bash Farm Animal Birthday Party Supplies. The best Children's Birthday Party Ideas start with a great birthday party theme, so for a fantastic Farm Animal themed Birthday Party, start with our amazing selection of Barnyard Bash Birthday Party Supplies. Barnyard Bash farm animal theme makes for a great party idea and for an amazing Birthday Party! Have a party to remember this year with a terrific kid's birthday party theme featuring Barnyard Bash! Great Birthday Parties start with Great Birthday Party Supplies!