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Exploring the environmental impact of including housefly larvae in piglet diets - Freija van Holsteijn

The livestock sector is in urgent need for alternative, more sustainable feed sources. Recent developments indicate environmental benefits of rearing insects for livestock feed. The aim of this study, therefore, was to assess 1) the environmental impact of housefly larvae fed with a mixture of organic waste and chicken manure, and 2) the environmental impact of including larvae meal in piglet diets. Additionally, we assessed a scenario that includes the compensation for current use of food waste (anaerobic digestion) and chicken manure (fertiliser) in the Netherlands, as well as the use of larvae manure for anaerobic digestion.

The livestock sector is in urgent need for alternative, more sustainable feed sources, because of the increased demand for animal-source food and the already high environmental costs associated with feed production. Recent developments indicate environmental benefits of rearing insects for livestock feed, suggesting that insect-based feed might become an important alternative feed resource in the coming years. The aim of this study, therefore, was to assess 1) the environmental impact of housefly larvae fed with a mixture of organic waste and chicken manure, and 2) the environmental impact of including larvae meal in piglet diets. Additionally, we assessed a scenario that includes the compensation for current use of food waste (anaerobic digestion) and chicken manure (fertiliser) in the Netherlands, as well as the use of larvae manure for anaerobic digestion. To determine the environmental impact life cycle assessment was used regarding global warming potential (GWP) expressed in kg CO2-eq, energy-use (EU) in MJ and land-use (LU) in m2, with functional units: one kg larvae meal and one kg piglet feed.

The environmental impact of larvae meal was 0.50 kg CO2-eq/kg larvae meal, 4.23 MJ/kg meal and 0.03 m2/kg meal. Adding larvae meal to piglet diet A resulted in a decrease of 2.85% for GWP, 4.62% for EU, and 1.19% for LU. Including the larvae meal in diet B resulted in a decrease of 9.12% for GWP, 15.63% for EU, and 3.47% for LU. The scenario in which current use of food waste, current use of chicken manure, and the impact from anaerobic digestion of larvae manure was included, resulted in an increase of 7.74% for GWP and 5.61% for EU, and a decrease of 1.09% for LU of diet A. The same scenario applied to diet B resulted in an increase of 24.33% for GWP and 19.22% for EU, and a decrease of 3.22% for LU. Overall, many uncertainties exist, however, using larvae meal in livestock diets will decrease LU. More research is essential to create an accurate picture of the environmental impact of larvae meal.



Student: FH van Holsteijn

Supervisor: H van Zanten, MSc

36 Ects