A simmering feud among Arizona off-track betting operators erupted in a verbal brawl last week when the leader of a Prescott horse track called for an attorney general probe during a meeting of the Arizona Racing Commission. David Auther, co-owner of Arizona Downs, told commissioners his business has been blackballed by Monarch Content Management, a Canadian company that owns the simulcast signal for horse tracks vital to the off-track betting market in Arizona.