Complex sentence: During the filming of the Metro-Goldwyn-Mayer (MGM) film "Lassie Come Home", the studios had decided to use a show collie trained by Frank Inn to portray the title character.
Split into simpler sentences: During the filming of the Metro-Goldwyn-Mayer (MGM) film "Lassie Come Home". The studios had decided to use a show collie trained by Frank Inn to portray the title character.