The farm at Lisduff was purchased by the O'Sullivan family in 1943 and in 1954 when the late John J. O'Sullivan took over management of it he commenced dairying and decided to introduce pedigree friesians as the basis for the efficient dairy-farming business.

Over the years cow numbers grew, AI has been exclusively used for the last 30 years and this has enabled access to the worlds best bulls. A small number of animals were imported from Canada, France and UK an embryos from the USA to start very successful cow families.

Today the business is run by the next two generations: John and his wife Teresa and their sons John, Victor, Donal, Robert and Colm. They are ably assisted by farm manager David McGrath. The farm enterprises extend to 490 acres (180 rented) carrying 250 cows, their followers, a herd of recipients for ET work and some tillage. 2011 has seen a new 32-unit De-Laval fully automated swing-over milking parlour installed at Lisduff and the establishment of another dairy unit on a second farm.

The aim today is the same as it was in 1954: to breed efficient cows that are a pleasure to milk and manage. That interest in breeding Black and Whites has made the O'Sullivans many friends and contacts all over Ireland and around the world for which they are very grateful.