Dried black soldier fly larvae (Hermetia illucens) as environmental enrichment for laying hens – a full-scale commercial study

There is a growing interest in the use of insect larvae to promote sustainability and welfare of farmed animals such as swine and poultry. Previous studies have piloted the provision of insect larvae in small experimental groups of broiler chickens and laying hens, but this has not yet been tested in full commercial scale. This study reports the first full-scale provision of dried black soldier fly ( H. illucens ) larvae (BSFL) to laying hens housed in commercial farms. The aim of the study was to assess the effects of the provision of dried BSFL as environmental enrichment on behavioural indicators of welfare in adult laying hens. To this end, 8 commercial flocks of laying hens were assigned to one of two groups: the Larvae group received 1 g/hen/day dried BSFL every 3 days from 30-55 weeks of age (woa). The Control group did not receive any larvae. The flocks were visited at 30, 55 and 70 woa and observed for plumage condition, fearfulness and behaviour. Larvae provision reduced fear of a novel object at 55 woa compared to the Control group ( ). In addition, Larvae hens showed less fear in the novel object test after 25 weeks of larvae provision compared to before ( ). Control hens performed more gentle and severe feather pecking compared to Larvae hens ( and , respectively). Larvae hens spent more time foraging and performing comfort behaviours while Control hens spent more time in locomotion and standing still ( ). There were no observed treatment effects on feather loss. These results indicate a high potential for dried insect larvae such as BSF to improve welfare by reducing fear and feather pecking behaviour in commercially housed adult laying hens.