Sheep numbers have dropped to under the 30-million mark for the first time since the 1930s, but in the past two decades farmers have become much more efficient.
Beef + Lamb New Zealand's Economic Service has released figures showing there were 19.96 million ewes and 9.76 million hoggets to the year ended June 2014.
Lambs born in the 2013-14 season numbered 25.56 million.
For the first time since 2006-07, beef cattle numbers increased - to 3.76 million - reflecting good feed conditions and improved returns, which led to farmers holding on to older cattle.
New Zealand sheep numbers peaked in 1982 at 70 million. Since then subsidies have been slashed and sheep farms have been converted to dairying or other land uses. By 1990 sheep numbers had fallen to just under 60 million, producing 40 million lambs a year.
Beef+Lamb chief economist Andrew Burtt said compared with 24 years ago, ewes were not only producing more lambs, but the lambs were heavier.
"Lambing percentages have gone up from one lamb per ewe to 1.2 lambs per ewe; that is 20 more lambs per 100 ewes than in 1990. Average carcass lamb weights have also increased from just over 14kg to just over 18kg.
"The real story here is about farmer response to land-use changes and market forces through better genetics and management."
Strong mutton prices, driven by rising demand from North Asia, encouraged a high level of cull ewe processing for the second year in a row.
Most of the decline in ewes was in the South Island, reflecting dairy conversions.
This year's breeding season is looking positive, with ewes in good condition and abundant feed at mating time, except in Northland and northern parts of the Waikato, where farmers experienced a second year of dry conditions. On average across the country, scanning results are estimated to be higher than in 2013.
Burtt predicted the mixture of good ewe condition and a benign autumn would see the lambing percentage go even higher. Beef prices were looking good, especially in the US, where there had been a supply shortage.
This, and increased demand as the economy rebounded, would encourage buyers to look at more NZ imports.
- The Dominion Post