There are concerns the blaze at the Zeagold facility will exacerbate a dearth of eggs caused by a ban on battery farming
The fire at a Zeagold farm broke out on Monday morning and had "taken better part of the day to contain", a spokesperson for the company said. Twelve workers who were on site were "unharmed but very distressed", the spokesperson said. Work was under way to assess how many hens had died, but Zeagold estimated it to be about 75,000. The company later revised that number down to 50,000.

The fire may have ripple effects beyond the immediate demise of the hens, with concerns it may worsen a national scarcity of eggs.

Zeagold's spokesperson said it was still too early to say how much of an effect the fire would have on the overall supply chain, saying: "There will be some impact obviously - it's not a great thing to happen in the middle of a shortage."

New Zealand has been in the grip of an egg shortage since the start of the year, when it put an end to battery farming. The ban had been in the works since 2012 and battery hen numbers had dropped over time to make up just 10% of overall egg production - but their final outlawing at the start of January has still been enough to jolt the egg supply chain, leaving supermarket shelves empty, shop owners policing tray purchases and big-breakfast lovers bereft.

Comment: The battery farm ban has 'been in the works since 2012', and, coincidentally, just passed last month...

The shortage has reached the point of contention: one small-town supermarket banned a cruise ship crew from further egg purchases after they cleared the shelves; newspapers have issued advice columns on egg-free baking and tofu scrambles; and in January, the SPCA released an advisory telling New Zealanders not to engage in kneejerk purchases of back yard poultry, after concerns that a rise in amateur chicken ownership would result in the animals not being properly cared for.

Before the Zeagolds fire, farmers had estimated they needed to raise another 300,000 hens before the shortage abated.

The Egg Producers Federation executive director, Michael Brooks, told Stuff on Monday: "Egg supplies are tight, so this will not assist in any way."