Early feeding experiences of piglets and their impact on novel environment behaviour and food neophobia

We studied whether feeding experiences of piglets during lactation influence novel environment behaviour pre-weaning and food acceptance pre- and post-weaning. In a 2 × 2 arrangement, litters (n = 10/treatment) received creep feed as monotonous diet (MO) or four feed items as diverse diet (DD) and the feed was provided without substrate (CON) or partly hidden in substrate (SUB). Two groups of four piglets/litter were exposed to a novel environment test (NET) at d21, a familiar food test (FFT) with creep feed at d22 and a food neophobia test (FNT) at d24 (cheese and chocolate), which was repeated at d25. At weaning (d28), four piglets from the same treatment were grouped (n = 10 pens/treatment) and fed a weaner diet onwards. At d41 a FNT (dried apple and crisps) was performed. No differences were observed in the NET. In the FFT, DD-piglets took longer to sample (P = 0.046) and less DD- than MO-piglets sampled feed (P = 0.02). Feed consumption increased (P < 0.001) and vocalisations decreased (P = 0.02) from day 1–2 of the pre-weaning FNT. DD-piglets vocalised more during the pre-weaning FNT (P = 0.03), and, unlike MO, their latency to vocalise did not increase from day 1–2. DD-piglets explored (P = 0.03) and sampled feed less (P = 0.007) than MO-piglets, but percentages of piglets exploring and sampling feed did not differ between treatments. Feed presentation in substrate did not affect piglets’ behaviour, except that the latency to sample feed did not decrease from day 1–2 for DD-CON, while it did for the other groups (interaction, P = 0.047). Post-weaning, DD-piglets took longer to explore the feed than MO-piglets (P = 0.04), and seemed more attracted to crisps, as they sampled it sooner (P = 0.01), and more DD-piglets sampled it (P = 0.02). MO-piglets, however, showed more exploration (P = 0.006) and sampling (P = 0.01) of apple, started sampling it sooner (P = 0.01) and a higher proportion of MO-piglets sampled apple (P = 0.02). Treatments did not affect the number and weight of the feed items consumed in the FNTs. Thus, early feeding experiences did not influence novel environment behaviour and feed intake in the FNTs, but pre-weaning dietary variety affected short- and long-term exploratory responses to novel feed. Unexpectedly, piglets with a diverse diet did not show signs of reduced food neophobia. This was possibly because of contrasts between the environment and the test conditions, resulting in MO-piglets being more motivated to explore in the tests than DD-piglets. Also the items selected as novel food may have played a role