This blend is traditionaly used to maintain a calm and comfortable stomach .Some horses do get a little uncomfortable in this area and will attempt to fill their stomachs with air to try and get back to normal.This may be particularly noticable after hard feed at any time of day because of the discomfort that starts at such times.In other horses there may be no clear link between feeding and behavioural problems.
Many nutrients can help horses in such situations but those in antisuck are particularly effective .Sometimes horses get used to gulping air down and the issue lies in the mind but almost always there is a more rational explination .