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

This study investigates the potential of replacing fishmeal with black soldier fly larvae (BSF) in weaning pig diets, aiming to overcome the limitations of traditional 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 body weight, with six replicates of eight pigs per pen in a randomized complete block design (RCBD). Experimental diets with different levels of black soldier fly (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. During phase I, the average daily gain (ADG) and gain: feed (G:F) ratio were decreased as the BSF larvae level increased (linear, p=0.03; p=0.03), and the BSF25 group had higher body weight compared to other groups (anova, p=0.01). In blood profiles, increasing levels of BSF larvae in the diet linearly decreased albumin levels at 28 d after weaning (linear, p=0.01). For immune response, there was a linear decrease in IgG concentration by increasing levels of BSF larvae (linear, p=0.05), and the BSF25 group had the highest value among all treatments only in phase I (anova, p=0.05). The results of this study demonstrate that BSF larvae meal can be a viable alternative protein source in diets for weaned pigs. The optimal ratio of BSF larvae replacing plasma protein is up to 25%, which leads to improved growth performance and immune response.