Effect of scattering black soldier fly larvae (Hermetia illucens) as enrichment on the litter on growth performance, gut development and active behaviour of fast and slower-growing broilers

This study evaluated the effect of whole black soldier fly larvae (BSFL) provision method (a trough or scattered on the litter) as an enrichment on growth performance, feeding behaviour, mobility and gut development of fast and slower-growing broiler strains. The effect of BSFL provisioning method (troughs or scattered on litter) and broiler strain (fast-growing Ross 308 or slower-growing Hubbard JA 787) was studied in a 2 ×2 full factorial layout with a total of 320 male broiler chickens (8 pens per treatment and 10 chickens per pen). The birds received 15 g of dehydrated black soldier fly larvae (BSFL) per pen between 09:00 and 11:00 h on days 8, 15, 22, 29, 36, and 42 of age. Growth performance and bird behaviour were recorded for each pen. Two birds/pen were sampled for gut morphometry at the starter, grower and slaughter stages for both Ross 308 and JA 787 birds. The effect of insect provisioning method (scattering and trough feeding) on slaughter bird weight (p = 0.92), overall FCR (p = 0.315), overall weight gain (p = 0.78), and overall feed intake (p = 0.324) was insignificant regardless of bird strain. Scattering BSFL on the litter significantly increased total activity (Δ = 1.02%, p = 0.018) when compared to trough feeding in the fast-growing (Ross308) broiler strains . There was no significant effect of provisioning method on total activity in the slower-growing broilers. Insect provisioning method had no significant effect on gut development (p > 0.05). It can be concluded that scattering BSFL on the litter increases active behaviours (running, walking, preening, stretching and dustbathing) in the fast-growing broilers without compromising growth performance and gut development. This increase in activity has the potential to improve health and welfare in the fast-growing broilers; however, further study is needed to support these claims. • Fast- and slower-growing broilers were provided with BSFL via trough feeding or litter scattering. • Scattering BSFL on the litter promotes active behaviour in the fast-growing broilers • Provision of dead BSFL increased broiler activity, with potential welfare benefits • Dead BSFL scattering is a promising enrichment strategy for broilers • BSFL provisioning did not compromise growth or gut morphology in broilers