A record lambing percentage this season has helped farmers to offset the effects of a declining sheep population, Beef and Lamb NZ said.
Research by Beef and Lamb's economic service estimated the number of lambs tailed in spring 2017 was 23.7 million head, up 1.9 per cent on the previous spring.
The average ewe lambing percentage for 2017 was 127.2 per cent, up 4.4 percentage points on last year and up 6.4 percentage points on the 10-year average (2008-09 to 2017-18) of 120.8 per cent.
Overall, this means 127 lambs were born per hundred ewes compared with an average of 121 over the last 10 years.
For spring 2017, a one percentage point change in the New Zealand ewe lambing percentage is equivalent to 178,000 lambs.
Andrew Burtt, chief economist of Beef and Lamb's economic service, said the record lambing percentage and more lambs from hoggets offset fewer breeding ewes.
"The report provides further evidence of sheep and beef farmers doing more with less," he said.
North Island lamb numbers were a major factor behind the overall lift in the New Zealand lamb crop with growth of 4.9 per cent (551,000 head) to 11.7 million head.
In the North Island, the average ewe lambing percentage for 2017 was 128.0, up 8.6 percentage points on last year.
"This was a record high, and was due to good climatic conditions and ewe condition at both mating and lambing for most regions," Burtt said.
"However, after autumn and winter conditions were generally good, but wet, lamb growth rates were lower than normal due to a lack of sunshine, cool damp weather and more lambs. This has had a negative impact on lamb growth.
"On a positive note, there were no adverse weather events during lambing," he said.
According to the survey, the number of breeding ewes declined 1.9 per cent to 17.8 million at 1 July 2017.
Beef and Lamb's crop survey is drawn from its Sheep and Beef Farm Survey, which covers a statistically representative sample of over 500 commercial sheep and beef farms.
-- Staff Reporter