With dairy farmers targeting a major herd expansion during the post-quota regime, choosing the right type of cow will be essential to a cost effective increase in milk production.
Tullamore Show has 39 classes for dairy animals across four breeds; the Pure Friesian, Jersey, Dairy Shorthorn and Holstein Friesian.
Over 250 animals have been entered in this year's show, making it the largest ever exhibition of top dairy animals at Tullamore. Some of the classes have considerable prize funds on offer, with up to €2,500 on offer for the winning animals, including the Senior Holstein Cow in Milk.
The show will have a new heifer's class this year, the Holstein Friesian 2.5-year-old milking heifer class, for animals born in January 2010.
Five classes are confined to exhibitors from Offaly and the neighbouring counties of Laois and Westmeath.
Dairy organiser Tommy Finlay admitted he was surprised by the level of interest in the dairy section this year.
"I was very disappointed early on when it looked like entries would be down," he said, "But there was a flood of entries in the last week and we ended up with the highest entry ever at the show."
First-prize winners in National Classes will receive a rosette and specially commissioned National Livestock Show medallion, as well as a cash prize, while the champion of each breed will receive a sash, rosette and a coveted gold medal.