# Supplementation of black soldier fly larvae (Hermetia illucens) as a sustainable protein source on growth performance, blood profiles, immune response, and diarrhea incidence in weaning pigs

## TL;DR

This study shows that black soldier fly larvae can replace up to 25% of plasma protein in weaning pig diets without harming growth or immunity.

## Contribution

The study identifies 25% substitution of plasma protein with black soldier fly larvae as optimal for growth and immune response in weaning pigs.

## Key findings

- Replacing up to 25% of plasma protein with BSF larvae improved growth performance and immune response in weaning pigs.
- Higher BSF larvae substitution levels (50% and 100%) led to decreased average daily gain and immune markers like IgG.
- BSF larvae at 25% substitution resulted in higher body weight compared to other groups in the first two weeks.

## Abstract

This study investigates the feasibility of substituting fishmeal with black soldier fly larvae (BSF) in weaning pig diets, with the objective of overcome the limitations of conventional animal protein sources and explore BSF larvae as a sustainable alternative protein.

A total of 192 weaning ([Yorkshire×Landrace])×Duroc) pigs (8.12±0.01 kg body weight [BW]) were assigned to four treatments based on sex and initial BW, with six replicates of eight pigs per pen in a randomized complete block design. Experimental diets with different levels of BSF larvae were as follows: 1) Control: corn–soybean-based diet, 2) BSF25: corn–soybean-based diet containing black solder fly larvae as a replacement for 25% of plasma protein, 3) BSF50: corn–soybean-based diet containing black solder fly larvae as a replacement for 50% of plasma protein, 4) BSF100: corn–soybean-based diet containing black solder fly larvae as a replacement for 100% of plasma protein.

From 0–2 weeks, the average daily gain and gain:feed ratio were decreased as the BSF larvae level increased (p<0.05), and the BSF25 group had higher BW compared to other groups (p<0.05). In blood profiles, increasing levels of BSF larvae in the diet linearly decreased albumin levels at 28 d after weaning (p<0.05). For immune response, there was a linear decrease in IgG concentration by increasing levels of BSF larvae (p<0.05), and the BSF25 group had the highest value among all treatments only in phase I (p<0.05).

The results of this study demonstrate that BSF larvae meal can be a viable alternative protein source in diets of weaned pigs. The optimal ratio of BSF larvae replacing plasma protein is up to 25%, which leads to improved growth performance and immune response.