Accident investigators say a 44-year-old motorcycle rider was hurt badly Saturday night when he hit a deer.  Forty-four-year-old Matthew McDonald suffered serious injuries in the accident in the Town of Trenton.  He is being treated in the intensive care unit in Froedtert Hospital in Wauwatosa for a severe head injury.  Investigators say McDonald was found lying in a ditch on the side of the road.  He suffered several broken bones and reportedly has more than 20 stitches on his head.  He wasn’t wearing a helmet.