National supermarkets have attributed the shortage to impending changes to the free-range standard and outdoor hens producing less eggs in the cold weather.

Egg Farmers Australia reported overall egg consumption is up three to four per cent, with free-range increasingly people’s first choice.

In March, the federal government introduced a legal definition of "free-range", which limits producers to one chicken per square metre and requires chickens to have "meaningful and regular access" to the outdoors.

But other requirements, such as the size and design of barns, are yet to be released. The uncertainty has halted expansion of free-range productions.

Many farmers have opted to hold off builds until they can ensure hatcheries meet new requirements. 

With more people buying free-range and operations waiting to expand, the yearly production drop is leaving supermarket shelves bare.

Victorian Farmers Federation Egg Group President Brian Ahmed said the current shortage was to be expected.

He said the free-range market already experienced a slight supply drop every winter, because hens with outdoor access lay less in cooler, darker months.

“This is a natural, seasonal variation caused by a drop in the volume of eggs produced by hens, who are feeling the cold,” he said.

“We’ve seen an increased demand for the free range product in recent years, which is why consumers are starting to notice the shortage of these eggs.”

The cage market is unaffected as artificial light keeps hens laying all year round.

A Woolworths spokesman said the egg shortage had affected retailers and customers across the country.

It originally only involved free-range eggs, but the shortfall is now having flow-on effects across all egg types.

“All major food retailers are experiencing an egg shortage, particularly in free range which is placing pressure on other egg ranges,” the spokesman said.

 “This has been driven by recent changes regarding the definition of 'free-range'. 

“We are working closely with our suppliers to ensure we meet demand as best as possible across our stores and we expect to return to normal supply shortly.”

More to come