I used the Animal Barn at Onkaparinga for a child's birthday. They catered it for me, including drinks & biscuits for the adults!

Activities for the children included
Pony rides & grooming
Small animal (rabbits/chicks etc) interaction
Feeding chickens, ducks, ponies, goats (all food supplied)
Making a feed cake for the pigs & feeding it to them
Toy tractors to play on

The great thing was that I got to be fully involved as I didn't have to organise/cook food etc nor did I have to clear up Bonus!! All I supplied was the birthday cake & lolly bags!

It was a great day!

Word of warning, if it is a wet day (or has been wet) don't dress the kids up & wear gum boots! As you would expect for an animal barn, it does get muddy when wet!

Approximate cost: $300.00 for a party of 10