Black soldier fly larvae bred in a converted shipping container are helping to meet the feed requirements of hens at a Powys free range egg farm and drive down its carbon footprint.

Batches of freshly-hatched black soldier fly neonates arrive at Wern Farm near Welshpool every few days from a breeding facility in Cambridge.

The larvae are grown in a mini insect farm built within a shipping container; the automated environment of Better Origin’s X1 unit tracks their growth using thermal cameras and artificial intelligence.

Growth is rapid – the larvae can increase in size by 5,000 times their body mass in less than a fortnight by living off rejected chicken feed from Lloyd’s Animal Feeds, with costs covered by the company.

Osian Williams, who farms with his parents, Dafydd and Eleri, and his partner, Nikki, keeps the unit supplied with this waste feedstock and with energy.

The waste is stored in a six-tonne silo located on the farm, refilled every one to two months, depending on consumption.

Regulations only allow pre-consumer waste, such as fruits, vegetables, grains, slaughterhouse waste, and unprocessed eggs and meat, to be fed.

Food waste is put in at one end and trays of mature larvae are taken from the other.

The average live larvae production of the X1 is 47 tonnes a year – this equates to over 129 kg per day.

The rate of growth of larvae depends on the type of feedstocks used; they have a high bioconversion rate, converting waste into high value fat and protein, and chitin, a prebiotic fibre.

While the pupa stage might be reached, ideally they would be fed just before that, after two weeks when the larvae are ready to be fed to the hens.

A new batch is then delivered to the farm to maintain a continuous supply for the 16,000 Bovan browns and 16,000 Lohmann browns.

Mr Williams’ ambition is to replace a percentage of his birds’ soy-based diet with maggots, to help reduce emissions, as the largest contributor to emissions on a free range egg farm is bought-in feed; it typically makes up more than 85 per cent of an egg’s carbon footprint.

Scientists at the UN’s Food and Agriculture Organisation have concluded that insects contain the necessary nutrients, especially protein, to replace between 25–100 per cent of soymeal for chickens.

Mr Williams is hosting the insect farm as a trial for Better Origin, a start-up launched by Cambridge graduates Fotis Fotiadis and Miha Pipan.

He currently feeds only 25kg a day of the larvae in his 32,000-bird system but he says the maggots are helping to enrich the hens’ diet; they are rich in protein and essential micronutrients.

“We feed 3.8 tonnes of feed a day so maggots are never going to replace that but they are definitely providing enrichment and we will be increasing the quantity fed as the trial progresses,’’ says Mr Williams, who sells his eggs to Lloyds.

Although maggots are 75 per cent water they have a protein content of around 10 per cent and a fat content of 15-20 per cent.

“The chickens get very excited when they see me arriving with the buckets of maggots,’’ says Mr Williams.