‘Carnivorous insects can consume such waste in a few days, [and] leave no contamination …’

– Senior lecturer in the Department of Animal Sciences at Stellenbosch University, Dr Elsje Pieterse, explaining how insects can be used for multiple applications in the agriculture industry

Insects can be used for multiple applications in the agriculture industry, as well as other industries, according to Dr Elsje Pieterse, senior lecturer in the Department of Animal Sciences at Stellenbosch University.

Speaking at the recent Animal Feed Manufacturers’ Association symposium in Pretoria, Pieterse, who runs trials on insect production for use in animal feed applications, said insects could be fed both ‘clean’ and ‘dirty’ waste when bred, before being processed into animal feed.

Insects could also play a role in reducing waste in the agricultural value chain.

Insects such as palm weevils, mealworms, crickets and locusts could be used to consume brewer’s yeast in a brewing business, for example, or food waste in a hotel business. To ensure that breeding insects’ reproduction was synchronised, they were fed formulated feeds, while those processed into animal feed received waste products for consumption. In this way insect farmers could maximise outputs and create a homogenous system.

According to Pieterse, the waste stream that was of most concern to the industry was that produced by abattoirs.

“Abattoir waste is buried and waste leaches into the ground and surface water. It takes months to break down. Carnivorous insects can consume such waste in a few days, leave no contamination and reduce the chances of disease,” she said.

Pieterse stressed, however, that when it came to breeding insects, there were the same risks as in livestock breeding, and stringent guidelines were needed for cleaning and processing.

The trials had shown that using these insects as chicken feed compared well to the use of traditional rations. “Trials showed an increase in broiler meat quality, with meat having better moisture-holding capacity. Eggs show better shell quality,” Pieterse said.

International trials on processing insects into pig feed also indicated that it was palatable to pigs and that their immune systems improved when compared with being fed traditional feed mixtures.

She added that there was great potential for the production of insects as a source of protein.

“For example, one can produce 37 000t/ha of insects for feed, compared with 5t/ha of soya,” Pieterse said. – Gerhard Uys