Dublin Zoo and Fota Island Wildlife Park spent €810,000 on meat, vegetables and plants for their lions, gorillas and other animals last year - an increase of 30pc.
The food spend is revealed in new accounts for the two attractions that show 2013 was a bumper year for the zoo and the wildlife park, with combined revenues growing by €375,000 to top €16.1m.
The 2.5pc increase in revenues contributed to the surplus at The Zoological Society of Ireland, which operates the two attractions, increasing by 4pc to €2.26m.
The accounts show Fota had 365,396 visitors.
Dublin Zoo director Leo Oosterweghel said: "The recent baby boom has helped to attract visitors, with new births in the past few months including two giraffes, a Goeldi's monkey and two Asian lion cubs. The arrival of three Asian elephant calves was the absolute pinnacle."
Visitor numbers to the zoo last year topped one million - the third year in a row that numbers passed the million mark.
The jump in revenues coincided with the spend on food for the animals last year increasing by €188,000, from €613,000 to €801,000.
A zoo spokesman said that €563,000 of the overall spend relates to Dublin Zoo with 41pc or €231,000 spent on brouse, made up of branches, bark and leaves along with hay and straw; while €169,000 was spent on pellets and supplements; €90,000 on fruit and veg; and €73,000 on meat and fish.
The spokesman said the zoo's Asian lions are fed four times a week and receive eight to 10 kilos of meat on the bone.
He said: "We mimic their feeding patterns in the wild, which includes starve days."
The spokesman added that the perception of gorillas eating bananas all day is wrong - they eat turnips, carrots, boiled potatoes, leeks and celery.
The zoo and wildlife park last year spent €283,000 on vet expenses while security costs topped €247,000.