Black soldier fly larvae study sharpens broiler feed debate

CURRENT BRIEF VERSION: Black soldier fly larvae meal is getting another look as a soybean meal substitute in broiler diets, with a new Veterinary Sciences study reporting that graded replacement levels affected growth, carcass traits, meat quality, and blood chemistry in Ross 708 birds. In the trial, 160 broilers were assigned to diets replacing soybean meal with black soldier fly larvae meal at 0%, 20%, 40%, or 60%, and the paper adds to a growing body of work suggesting insect proteins can support broiler production when diets are carefully formulated. Related broiler studies in Animals have found that low-level inclusion of full-fat Hermetia illucens or Tenebrio molitor meals can be used without major performance losses, while other poultry research has shown outcomes can vary with inclusion rate, nutrient balance, chitin content, and the form of the insect ingredient. Separate broiler work on low-soybean-meal diets also suggests that simply cutting soybean meal is not automatically benign: a 10% reduction increased mortality, feed intake, reduced ether extract availability, and shifted cecal microbiota toward higher Helicobacter and Campylobacterota abundance, with raffinose only partly reversing those changes. (mdpi.com)

Why it matters: For veterinary professionals working in poultry health and production, the bigger story is less about a single feed ingredient and more about the tradeoffs around sustainable protein sourcing, gut health, nutrient digestibility, and carcass quality. Black soldier fly ingredients are attractive because they may reduce reliance on soybean meal and fit broader sustainability goals, but the evidence still points to formulation limits: inclusion level, amino acid balance, processing method, and possible effects from chitin all appear to shape bird performance and health outcomes. Meat quality is part of that equation too; other broiler nutrition studies, including work with phytogenic additives such as Stevia rebaudiana extract, show that feed changes can alter sensory traits, physicochemical measures, and storage-related quality markers even when growth is not the only endpoint. In the U.S., dried black soldier fly larvae already have an AAFCO ingredient definition for use in salmonid, poultry, and swine feed, provided the larvae are raised on feed-grade materials, which makes the research more commercially relevant than it would have been a few years ago. (aafco.org)

What to watch: Expect follow-up work to focus on optimal inclusion thresholds, economics, gut and immune effects, and whether newer commercial black soldier fly products can deliver consistent results at scale under field conditions. Work in other species is reinforcing the same threshold question: in grey mullet, partially defatted black soldier fly meal preserved growth overall but higher inclusion levels worsened intestinal condition and produced dose-related spleen changes, while a lower-inclusion diet appeared most favorable. And outside poultry, live Tenebrio molitor larvae improved early growth, feed efficiency, and health indicators in post-weaning piglets, suggesting insect ingredients may have functional as well as nutritional roles depending on how they are delivered. (publish.csiro.au)