The egg industry has introduced a voluntary traceability ink-stamp for individual eggs, and the country's largest commercial producer has already adopted the scheme.

The five-digit food-grade ink stamp can be checked against the website Trace My Egg to verify which farm it came from and how it was laid.

The egg producer industry is at present phasing out the conventional cage systems, in a move to barn-raised or free-range farms, with cages to be out by the end of 2022.

This has prompted an almost 15 per cent decline in hen numbers, as some producers leave the industry.


Otago-based Mainland Poultry is the country's largest egg producer at about 30 million dozen eggs a year and has recently been developing a large free-range poultry farm south of Moeraki.

A stamped egg. Photo / Gregor Richardson
A stamped egg. Photo / Gregor Richardson

Mainland general manager of sales and marketing Hamish Sutherland was contacted and said the industry had faced ''issues with product integrity''.

''This is a significant first for the primary industry, allowing consumers to trace back to the [farm] source and the product's integrity,'' he said.

In early 2017 the Serious Fraud Office investigated claims millions of caged eggs were being sold as free range by a wholesaler, which affected several other producers.

Sutherland said Mainland was now ''well down the path'' of phasing out its conventional cages and investing further in barns and free range.

The voluntary scheme, which begins next month, already has about 70 per cent of egg suppliers to supermarkets signed up, who will also carry the Trace My Egg logo on each carton.

''There has been a lot of change in the industry, with the cages out and bringing in a more welfare-friendly format,'' he said.

Egg Producers Federation (EPF) executive director Michael Brooks said while New Zealand's egg industry had world-class farming practices and a unique disease-free status, ''a few bad eggs have threatened its reputation in recent years''.


''To help prevent this from reoccurring we have purpose-built a programme specifically for New Zealand that provides consistent source assurance across the industry and puts control back in the hands of the consumer,'' he said.

The EPF has appointed auditor AsureQuality to provide random spot checks on participating farms, in addition to being audited by the Ministry for Primary Industries.

Dunedin businessman Michael Guthrie co-founded Mainland Poultry in 1997, and sold his 76.6 per cent stake in 2017, propelling him on to the annual rich list with an estimated net worth of about $200 million.