Spent hemp biomass in broiler diets: low inclusion is not a licence for broad substitution

A by-product from cannabidiol extraction, spent hemp biomass cannot automatically be regarded as a safe poultry-feed ingredient merely because it may reduce costs or repurpose residual material. A newly published broiler feeding trial shows clearly that, even when diets are formulated to provide equal energy and protein, the inclusion rate determines the outcome. In the experiment, 200 Cobb-500 chicks received diets containing 0, 5, 10 or 20% spent hemp biomass for 42 days. Feed intake did not decline, but feed conversion and body weight were negatively affected from the 10% level upward. At 20%, breast weight was lower, drip loss was higher and shear force increased—an indication of lower tenderness. The highest inclusion also changed muscle lipid profiles and was associated with higher feather corticosterone, a marker of chronic stress. The practical message has two sides. Inclusion at 5% did not cause measurable adverse effects on health or productivity in this trial. But the outcomes at higher levels rule out treating the biomass as a linear replacement for conventional feed components. Crucially for the meat chain, the effects were not confined to growth: breast yield, water retention and texture were also affected. Spent hemp biomass is not authorised by the US FDA-CVM for livestock feed, partly because of questions about potential cannabinoid residues in tissues. This study does not replace a regulatory assessment. Its value is in defining the next technical step: analytical characterisation of each batch, residue verification and validation of carcass and meat quality must accompany any potential use.