Latest dairy statistics, released by dairy servicing company LIC, reveal that average production measured on a per cow and a per hectare basis was last season higher in the South Island than the industry's traditional North Island stronghold.
The statistics also show there were 194 fewer herds last season, now totalling 11,436, but the number of cows in those herds was increasing, with an average size of 351 cows, double what it was 20 years ago.
LIC said in a statement that 19% of herds have 500 or more cows, 16% between 200 and 249 and 61% between 100 and 349 cows.
Herds between 850 and 899 cows had the highest production per cow.
The national herd exceeds four million cows, with 79% of herds in the North Island and the greatest concentration (32%) in South Auckland.
South Island farms are bigger than those in the North Island, with just 21% of the national herds but 31% of cows at 1.2 million.
South Canterbury had the largest average herd size at 711, but the South Island average herd size was growing, and has hit 526.
Drought last summer and autumn had a huge impact on 2007-08 production, with 3.2% less milk solids processed.
The country's dairy companies collected 14.7 billion litres, or 1.27 billion kg of milk solids (kg/ms) for the season.
