"There was one that had about 15 big slash marks.
"Usually people just flog them for meat but they've just mutilated these six. They've obviously been penned up and chased around."
He said there was a half acre pen where the sheep were put when the course was in use and he believed the offenders had locked them in there before taking to them with a knife.
"They must've known what to do," he said.
"They took the whole front shoulder off one and you have to know what you're doing to do that."
Mr Dobson said police had been out on Friday afternoon to take photos.
"Someone must be covered in blood or something," he said.
"Someone could say 'hey, my mate turned up last night covered in blood'."
Mr Dobson believed it would have happened overnight on Thursday.