Domestic milk intake by creameries and pasteurisers was estimated at 150.9 million litres for January 2018, according to the Central Statistics Office (CSO).
This was 1.5% above the corresponding 2017 figure, which amounted to 148.7 million litres for January of that year.
This is 5.8% higher than the 26.2 million litres sold for the corresponding period in 2017.
Comparing the January 2018 milk produce figures with those for January 2017 shows that the total milk sold for human consumption also increased by 2.8% to 45.6 million litres.
In addition, it was found that butter production was up 49.5% to 7,760t.
Northern Irish milk boom
Meanwhile, in Northern Ireland, dairy farms produced a record milk volume output in December, according to the latest agricultural survey figures.
It follows on from a record November, when producers also saw prices break the 33p/L barrier – with the average litre fetching 33.29p.
However, despite the continuing drive on production, December saw the average farm-gate price paid per litre of milk slide slightly to 32.65p/L.
The figures also showed that the region’s dairy herd stood at 312,500 cows in December 2017 – marginally up on dairy cow numbers recorded in December 2016, but showing little or no difference when compared to the total dairy herd size in 2015.