Australia's lamb slaughter plummeted to 1.45 million head in May, 33 per cent below year-ago levels and the lowest monthly slaughter since January 2012.
All states recorded big falls from year-ago levels with South Australia throughput easing 40pc from May 2019 to 158,250 head.
NSW and Victoria slaughter reported year-on-year declines of 18pc and 35pc to 387,300 and 710,600 head, respectively.
The Australian Bureau of Statistics slaughter and production data has been compiled by Meat and Livestock Australia.
Despite widespread rainfall earlier in the year, competition in the store market between restockers and processors remained robust, pressuring the availability of finished lambs, MLA said.
In line with reduced slaughter levels, national lamb production for May sat 30pc below year-ago levels at 36,075 tonnes carcase weight.
Carcase weights continue to be buoyed by lot fed lambs entering the market at a higher weight bracket, MLA said.
In May, national lamb carcase weights averaged 24.9kg a head, 1.2kg higher year-on-year.
National sheep slaughter halved from year-ago levels to 325,900 head in May, the lowest national throughput since July 2016.
While significant declines from year-ago levels were reported across all states, South Australia saw the largest reduction, back 66pc to 20,020 head, while NSW and Victoria eased 45pc and 63pc to 116,400 and 93,770 head, respectively.
With the exception of January, national sheep slaughter has been tracking well below 2019 levels so far this year, as increased stock retention and two large turn-off years in 2018 and 2019 limits the volume of sheep available for processing.
The steep decline in slaughter resulted in national mutton production falling 46pc year-on-year to 8,161 tonnes in May with significant declines recorded across all states.
Subdued sheepmeat production has placed downward pressure on exports, with sheepmeat shipped quantities tracking considerably below 2019 levels.
National sheep carcase weights averaged 25kg a head in May, an increase of 1.9kg from year-ago levels