Complex sentence: From 1929 to 1931, MGM produced a series of comedy shorts called "All Barkie Dogville Comedies", in which trained dogs were dressed up to parody contemporary films.
Split into simpler sentences: From 1929 to 1931, the MGM motion picture studio produced a series of comedy shorts called "All Barkie Dogville Comedies". The actors in these films were trained dogs, dressed up to parody contemporary films.