Mr Hensley woke to his own dog barking about midnight on Sunday.
He stood at the window but could not see anything, so he did not know there was a problem until he received a call from one of the neighbours, saying he had found a dead bird in his garden, he said.
He raced to the enclosures to see what wrong and was greeted with the sight of feathers strewn all over the ground and large holes in the netting where the birds had tried to escape.
"They can't see at night, so they would have been running blindly around the pens, wondering what was going on," Mr Hensley said.
The breeding programme had been under way for five years, with some birds going to farms for shooting and others about to be sold for eating this year.
Mr Hensley said a stray dog resembling a German shepherd cross was running around yesterday morning, and he ran to get his gun, but the dog had run off by the time he got back.
He had heard another neighbour had tried to shoot two dogs that were wandering around on Sunday, but the dogs had run off towards Clyde.
Police and the SPCA have been to visit the scene.
