The title and album cover comes from a newspaper headline “Atom Heart Mother.”
The story was about a pregnant woman who received an experimental pacemaker.
The cow on the cover had nothing to do with the story – Pink Floyd chose the cow because it was the least psychedelic thing they could think of.
The song is 23:45 long and has no lyrics other than the background sounds “Silence in the studio!” at 19:06 and “Here is a loud announcement” at 17:25.