There were 13.6 million large farm animals in the country in June 2012, according to new figures from the Central Statistics Office.
The figures show marked increases in the number of sheep and cattle, while there were decreases in the number of farmed deer and goats.
The number of bovines increased by 4% to 6.7m in the year, while sheep numbers increased 7% to 5.1m.
The total number of pigs also increased 1.4% to 1.5m.
Horse and pony numbers were up slightly to 111,000.
The only decline in large farm animals was in goats and farmed deer, which together only account for 12,000 animals.
The CSO's June survey provides a picture of animal numbers at the peak farming period of the year.
The figures are based on returns from the Department of Agriculture and CSO surveys.
The survey also shows a 6% increase in the year in the area planted under cereal crops at 315,000 hectares. This includes wheat, oats and barley.
However, there was a decrease in the area of potatoes planted, down 13% to 9,000 hectares.