Mr Fitzgerald estimates 5,000 jobs will be created in milk processing for new farm entrants and farm labourers.
He said up to 8,000 jobs will be created in areas such as animal feeds, fertilisers, agri wholesale and advisory roles, at least 1,500 in meat factories due to the increased size of the national dairy herd, and in other related downstream roles.
The other 500 jobs will be in collection, distribution and administration.
"I am deliberately trying to be as conservative as possible, but there is no doubt that this is a big growth opportunity," said Mr Fitzgerald.
"There will be another 2.2bn litres of milk to be translated into dairy products and exported. This translates into €1.3bn-€1.4bn in exports.
"More importantly, as 90% of all of the inputs in this industry are supplied from within Ireland, this is a far bigger prize for the Irish economy than a sector such as high tech, which imports its raw materials."
Dairy already directly and indirectly employs 34,000 people in Ireland. Dairy exports were valued at €2.66bn in 2011.
With the abolition of EU milk quotas in 2015, that growth is predicted to increase substantially. The Food Harvest 2020 Report anticipates 50% growth.
One University College Dublin report estimated agri-food supports around 200,000 jobs in Ireland.
A report produced by Mr Fitzgerald for Ibec six years ago estimated each job in agriculture supported five across related sectors.
"This growth will definitely happen," said Mr Fitzgerald. "There are now 40,000 jobs across the dairy sector; 7,000 in processing and manufacturing; 16,000 dairy farmers; and another 17,000 jobs in farm supplies, machinery, labouring and other secondary areas.
"We have had no dairy growth in the EU since 1984. It cannot happen incrementally due to quota restrictions. It has to happen overnight in 2015, and there will be a big wall of milk to deal with in year one."
To fund this expansion, Mr Fitzgerald suggested the Government should seek an EU short-term growth fund, along similar lines to monies which funded ESB Electric Ireland’s move into alternative energy.
