Wow, talk about censorship

Apparently he had a very little part

Borgnine didn't make his film debut until 1951. At the time of this film, he was still in Virginia in a theater company there. Here's a quote from IMDB's bio of Borgnine covering that period:

At age 18, after graduating from high school in New Haven, and undecided about his future career, he joined the United States Navy, where he stayed for ten years until leaving in 1945. After a few factory jobs, his mother suggested that his forceful personality could make him suitable for a career in acting, and Borgnine promptly enrolled at the Randall School of Drama in Hartford. After completing the course, he joined Robert Porterfield's famous Barter Theatre in Abingdon, Virginia, staying there for four years, undertaking odd jobs and playing every type of role imaginable. His big break came in 1949, when he made his acting debut on Broadway playing a male nurse in "Harvey".

In 1951, Borgnine moved to Los Angeles to pursue a movie career, and made his film debut as Bill Street in The Whistle at Eaton Falls (1951).