Rapper Chief Keef is literally becoming a naysayer. ... because of a very unorthodox form of community service he's been ordered to perform.
Keef -- who was arrested for speeding and given 60 hours of community service -- will do the time at a Chicago area equestrian center which uses horses to provide physical and occupational therapy for people with disabilities.
The folks at Horsefeathers tell us ... Keef will feed and groom the animals. He'll also clean the barn and scoop up horse poop.
BTW... Keef has other legal problems -- he was just ordered to go to rehab for violating his probation by testing positive for marijuana.
The judge chose rehab because ... well, how much horses**t can one person really handle.