Discussing Hug A Vegetarian Day on September 27 with co-host Charlton Tobias, Mann said: "I thought about it for a long time before I actually took the step but I am totally vegetarian.
"Not totally vegan yet, to my shame I haven't kicked dairy, and the dairy industry is horrific."
'Individual points of view'
The comment received backlash from advertisers Woodlands Dairy who registered an official complaint against Mann.
According to Press Reader, Algoa FM Managing Director Alfie Jay said Woodlands never requested for Mann to be fired, adding: "Algoa FM respects entirely that people hold individual points of view.
"However, the expression of a point of view has the actual and/or potential consequence of undermining the legitimate and equally important interests of another."
'Archaic and obsolete ideas'
The news has caused outrage amongst vegans and animal-rights activists - resulting in a petition against Algoa FM's decision to fire the presenter.
The petition, which has exceeded 4,000 signatures, accuses the radio station of violating 'the right to free speech and the free exchange of ideas'.
"The dictatorship of archaic and obsolete ideas will destroy this radio station," the petition description reads.
You can sign the petition here