The national sheep flock is tipped to reach more than 70 million this year.
The forecast of a wet spring in many key sheep producing regions will drive the increase in numbers, according to Meat & Livestock Australia's 2021 October sheep industry projections, released on Friday.
From a high of 180 million in 1970, numbers fell to 68 million in 2009-10, which was the smallest Australian sheep flock size since 1905.
The flock is also expected to grow beyond this in the coming years and is forecast to reach 76 million head by 2023 - its largest point since 2007.
MLA's market information manager, Stephen Bignell, said the eastern states have been the key drivers behind this growth, supported by back-to-back strong seasons.
"The pace of the national rebuild has been even faster than initially expected because producers are using the good season to increase stocking rates and retain breeders," Mr Bignell said.
"We're expecting the season to have a positive impact on carcase weights, which have been revised up to 24.8kg for lambs and 25.6kg for sheep.
"Lamb slaughter is also expected to rise by three per cent this year, although it's forecasted that sheep slaughter will be at its lowest level since 2011 because of the additional stock retention."
Mr Bignell said the combination of increased slaughter levels and carcase weights for lambs was a good sign for production, which is set to be the third highest on record in 2021 - before hitting a record in 2022.
"We're expecting that lamb production will perform well during the back end of this year, supported by a combination of new season lambs from the spring flush and old season lambs producers have held onto for additional weight gains," Mr Bignell said.
"There are current processing restrictions in Victoria due to the recent COVID-19 outbreak that could impact these figures, given the state processes half of the national lamb slaughter, however we expect that NSW will pick up some additional production if required, as it did in a similar situation last year."
Despite strengths in production, slaughter and flock growth, Mr Bignell said there were still some challenges for the sheep industry to work through.
"Live exports of sheep could fall this year, as the strong season and high domestic livestock prices have placed downward pressure on live export volumes," Mr Bignell said.
"There are also lingering impacts of COVID-19 causing disruptions in some of our key overseas markets, including the Middle East, but we expect a recovery in this as economies track back towards pre-pandemic levels."
Domestic sheep and lamb prices are expected to remain elevated for the remainder of the year and beyond, buoyed by demand from both restockers and feeders, as well as from export markets, where lamb's popularity as a niche product is growing.
This demand has resulted in new records for the National Restocker Lamb Indicator of 1,034/kg cwt in September and the National Trade Lamb Indicator of 951/kg cwt in August, however, increased new season supply has recently softened these prices.
As the projections suggest, increasing demand for sheepmeat, a positive weather outlook and strong production fundamentals all support the Australian sheep industry's position as a global leader ready to capitalise on growing domestic and international opportunities.
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