Effects of the administration on live larvae as enrichment material on weaned piglets behaviour

Black Soldier Fly (BSF) larvae could be used as a feed ingredient (larvae meal, LM) and as an enrichment material (LL, live larvae). In a study, LL improved piglets behaviour in an experimental setting (Ipema, 2021). We tested the effects of LL administration under conventional rearing conditions. Forty-eight piglets (commercial hybrids, 28d old) receiving the same diet (containing 6% LM) were split into two experimental groups (4 replications of 6 piglets per group): C (control, kept in standard commercial conditions) and LL (receiving 300-600g/pen/day of BSF LL). The trial lasted 40 days. Diurnal behaviour was videotaped every 10 days and analysed (scan sampling technique) to obtain individual time budgets. Data were submitted to ANOVA using the group as fixed effect and the pig as random effect. Time budgets were affected by live larvae administration, with LL piglets spending 13% of the observed time interacting with larvae, reducing time spent exploring the pen floor (3.5 vs. 5.1%, F(191)=6.6, P<0.05), and manipulating the traditional enrichment (metal chain and wood logs, 1.3 vs. 4.8%, F(191)=36.6, P<0.01). Social interactions were also lower in LL piglets (7.6 vs. 9.6%, F(191)=8.4, P<0.01). The overall activity level (time spent resting) was not affected (45.0 vs. 47.7%, F(191)=2.5, P>0.05). Pending more extensive behavioural observations (in continuous behavioural analysis is in progress), our results indicate that BSF LL administration can improve piglets behaviour on farm by shifting the exploratory behaviour from the pen fixtures and traditional enrichments to larvae without increasing the animals’ activity levels.