Can black soldier fly larvae (Hermetia illucens) be utilized by ruminants? a meta-analysis of performance,...

This meta-analysis examined the effects of dietary black soldier fly (BSF) on ruminant production, digestibility, and rumen fermentation parameters, and key moderating variables that influenced the animal responses. In ruminants, a total of 12 studies were identified through Scopus, Web of Science, and PubMed and were analyzed using mixed model meta-analysis using the metafor package in R software.

The results indicated that BSF inclusion did not affect dry matter intake (DMI), average daily gain (ADG), feed efficiency (FCR), and digestibility outcomes. However, crude protein intake decreased (RMD = - 3.54%; P = 0.006) with BSF inclusion. While milk yield and dairy efficiency were unaffected, BSF inclusion exhibited a positive effect on milk fat percentage (+ 3.16%; P = 0.001). Rumen fermentation was enhanced by BSF inclusion, as indicated by higher total VFA production (+ 7.69%; P = 0.024). Animal species and inclusion levels were significant moderators of DMI and DMD, in which BSF inclusion in goats resulted in improved ADG (P = 0.019) and DMI (P < 0.01), while no effect was found on sheep. Beef and dairy cattle displayed improved DM digestibility (P = 0.04). No major effects were detected for BSF type or country of study, and publication bias was not evident for the main production outcomes.

Our meta-analysis suggests that BSF-derived ingredients can be incorporated into ruminant diets as a partial replacement for soybean meal without compromising overall animal performance while providing specific benefits for milk quality and rumen fermentation. However, additional studies on growing ruminants, particularly steers and lambs, are warranted, as current evidence on these classes is limited.