# Standardized Ileal Digestibility of Protein and Amino Acids in Black Soldier Fly Larvae and Duckweed in Broiler Chickens

## TL;DR

This study compares the digestibility of protein and amino acids in black soldier fly larvae and duckweed for use in broiler chicken feed.

## Contribution

The study provides new data on amino acid digestibility in black soldier fly larvae and duckweed for poultry nutrition.

## Key findings

- Black soldier fly larvae had higher crude protein digestibility than soybean and rapeseed meals.
- Duckweed's high fiber content reduced amino acid digestibility in broiler chickens.
- Fat content in black soldier fly larvae enhanced amino acid digestibility.

## Abstract

Insect meal and duckweed are increasingly recognized as novel feed ingredients that can contribute to sustainable poultry production. Determining the standardized ileal digestibility of crude protein and amino acids is essential for formulating nutritionally balanced diets and evaluating the potential inclusion of insect meal and duckweed in broiler chicken nutrition. Black soldier fly is an insect characterized by rapid growth, a short rearing cycle, and the ability to utilize a wide range of substrates. The high fat content in black soldier fly larvae resulted in greater amino acid digestibility than soybean meal and rapeseed meal. Duckweed, including Lemna and Spirodela, is a tiny aquatic floating plant that represents a valuable source of plant protein. However, its high fiber, tannin, and ash contents can reduce amino acid digestibility. Therefore, black soldier fly larvae and duckweed can be supplemented in poultry diets, but differences in chemical composition and amino acid digestibility should be carefully considered during feed formulation to meet the nutritional requirements and effectively optimize the growth performance of broiler chickens.

Black soldier fly larvae (BSFL) and duckweed are potential alternative feed ingredients for sustainable poultry production. This study aimed to determine the standardized ileal digestibility (SID) of amino acids (AAs) in BSFL, Lemna, and Spirodela compared with soybean meal and rapeseed meal. Six cages of eighteen broiler chickens were allocated to each treatment. The crude protein (CP) content was highest in soybean meal (511 g/kg dry matter; DM), intermediate in BSFL (391 g/kg), and rapeseed meal (335 g/kg DM) and lowest in Lemna (185 g/kg DM) and Spirodela (145 g/kg DM). Ether extract was highest in BSFL (95 g/kg DM), whereas crude fiber was highest in Lemna (109 g/kg DM) and Spirodela (171 g/kg DM). The SID of CP was higher (p < 0.05) in BSFL (89.0%) than in soybean meal (82.3%), rapeseed meal (71.3%), Lemna (70.2%), and Spirodela (44.9%). The SID of all essential amino acids (AAs) was higher (p < 0.05) in Lemna than in Spirodela, but it did not differ from that in rapeseed meal. In conclusion, the high fat content in BSFL can enhance AA digestibility, whereas the use of duckweed may be limited by its fiber fractions, which negatively impact the SID of CP and AAs in broiler chickens.