The Port Stephens community, and wider Hunter region, rallied around the organisation after thieves stole from the Raymond Terrace centre on Sunday.

They stole a month's supply of horse feed and a wheelbarrow.

Caretaker Phil Hudson made the discovery on Monday morning.

"When I got in, I saw the door to the feed room was wide open," he said.

"It is just so disappointing."

RDA provides assisted activities, such as horse riding, for people with disabilities as a way to develop physical and social skills.

The organisation relies on fund-raising and volunteers to provide this service to the community. The theft was a big blow to the group's finances.

Since news of the theft broke, residents have rallied to help.

Instead of needing to find a month's worth of feed, the organisation looks set for the entire year.

Businesses such as Alanwood Park Agistment and Norco Rural swiftly pledged to replace the stolen feed, with Norco also supplying a wheelbarrow.

Port Stephens Mayor Bruce MacKenzie was shocked to discover that RDA had suffered theft.

"They do a fantastic job for the community.

"I can't believe some scum would come along and take from a place that helps so many people," he said.

Mr MacKenzie pledged $1000 worth of feed from the mayoral funds and had the delivery and order sorted within four hours of finding out about the incident.

The RDA has 15 horses that are old and need a specific type of feed. To help out or for more details, call RDA on 4987 1402.

Anyone with information about the theft should call Crime Stoppers on 1800 333 000.