Though nutritionally sound and immune modulating, insect meal is currently still too expensive to be useful to most pork producers
By Jackie Clark
Staff Writer
Farms.com
Researchers from the University of Guelph investigated the feasibility of using insects in nursery pig feed.
Dr. Lee-Anne Huber and Michelina Crosbie, a professor and MSc student in the department of animal biosciences at the University of Guelph, included black soldier fly larvae meal (BSFLM) to replace either 25 or 50 per cent of the highly digestible animal proteins in nursery diets. They compared pig development with conventional diets with and without in-feed antibiotics.
The researchers used BSFLM because “we were looking for something that would be feasible to actually include in animal livestock diets. So, it needed to be one that was available in relatively (large quantities) or else there’s no point,” Huber told Farms.com. “The black soldier fly seems to be one of the most common ones that’d produced on a larger scale, having enough larvae biomass available to include it in diets, so that’s why we went with it.”
Black soldier fly larvae “are easy to grow, easy to harvest, they’re not picky eaters so they’ll grow on a variety of different substrates which gives flexibility for raising them. They don’t require very much water, so they are a very small environmental footprint species. They don’t require a lot of space either,” she explained.
The larvae biomass is about 40 per cent protein, high in fat, and therefore energy, “and the amino acid profile is also favourable,” Huber added.
The scientists fed the treatments to newly weaned nursery pigs for 42 days.
“We had to see if the pigs would actually eat it, and they did. Which isn’t surprising, if you think about pigs in the wild,” Huber said. “They’re rooting around eating grubs and stuff, so insects in their diet isn’t a new thing.”
However, other factors limit the current usefulness of BSFLM in pig diets. Start-up companies that are producing the BSFLM were relatively new with high input costs,
“That insect meal is going to have to come down a lot in order to be economically feasible in our rations,” Huber explained. In 2018 the cost of BSLM was about $12/kg, much higher than soybean meal – which is a nutritionally comparable feed ingredient.
Specified uses for the insect larvae meal or further investment in the industry may help make costs more practical.
“Based on that immune response that we saw, those pigs responded really well to vaccination, and there are some immune modulating compounds in the black soldier fly larvae … that might be the way to go with it to make it more cost effective,” Huber said.
Feed ingredient producers could “extract the compounds from the meal and concentrate them and feed them as a pure additive to the diet,” she explained. “For example, you could extract the chiton, which is the exoskeleton, which we think might have some immune stimulating properties. And you could extract the medium-chain fatty acids, which we also think might have some anti-microbial properties.”
The pure extracts would be costly, she added. “But they’re so concentrated, you would include them in the diet in very small amounts.”
This approach may be more economically feasible for pork producers.
“You would be putting (BSFLM) in the diet not to supply nutrients, but for their immune modulating properties,” Huber said. This application may be most effective for nursery pigs.
“In the last couple of years the cost has come down a little bit. My guess is it’s maybe at $8/kg. So it’s still expensive but it’s coming down, and the reason why is the economies of scale,” she added. “Companies are scaling up, the federal government has started taking notice of them and investing in infrastructure.”
Costs may continue to come down in the future, making BSFLM inclusion in pig diets more feasible.
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