The animal feed and biotechnology business has earned Dr Pearse Lyons and his family a huge €1,925m (£1,500m), up €640m from 2015.
Alltech has more than doubled its sales in the last four years to over €2bn. Internationally, it has been integrating its business, becoming more focused on direct sales to farmers, and just recently it has acquired Carlow-based manufacturer Keenan's.
Billionaire beef industry
Beef baron Larry Goodman and wife Kitty are 20th on the list with a €680m (£530m) empire, up €19m from last year.
In 36th position is Bert and Maurice Allen of Slaney Meats, who are worth €346m (£270m), down €10m.
Belfast grain merchant Robert Barnett and family place 48th on the list with €233m (£182m).
Jack and Jim Dobson of Dunbia are 146th with €90m (£70m), while the Keating family of Kepak came 196th with €68m (£53m).
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