A mix of black soldier fly and an aquatic plant could be added to the diets of layer hens without reducing egg quality, the results of an Indonesian study suggest.
Researchers at Universitas Syiah Kuala set out to find out what impact a combination of black soldier fly larvae meal and meal from the aquatic plant azolla would have in the diets of hybrid chickens, which are bred for high productivity.
They tested feeding five different diets to randomised groups of birds: a basal diet typically used in the industry, and four diets reducing the basal diet component to 90%, 80% and twice to 85%, making up the remainder with different quantities of the novel ingredients. They recorded egg shape, egg weight, Haugh units, which are a metric based on egg white height and egg weight, yolk colour and egg grade, which is an industry standard based on Haugh unit measurements.
No hits to egg shape, weight or colour
They found that adding up to 10% each of the insect and plant meals had no statistically-significant impact on any of the egg quality metrics, meaning that potentially, 20% of birds’ diets could be replaced with these sustainable and potentially cost-saving feed options.
They saw the best results for egg shape in the treatment containing 85% basal feed, 10% black soldier flour and 5% azolla flour, recording egg shapes that were not too round and not too oval. This could be due to the high protein content found in this diet, they suggested.
In the final egg grading, the treatment containing 90% basal diet, 5% black soldier fly and 5% azolla produced the best results, with no eggs in Grade C and 16.6% and 16.7% in Grade AA and A, respectively.
New options needed
There is now considerable evidence about the nutritional qualities of black soldier fly and its suitability as both a feed and food, but there is now a growing body of research highlighting the potential of azolla as well as other aquatic plants. Azolla has a symbiotic relationship with algae to concentrate its protein content but is considered a serious invasive species in some parts of the world, including the UK.
With feed costs an ever-present concern for poultry producers, particularly in developing countries, cheaper alternatives such as meals derived from insects and plants could prove to have a wide appeal.
