Experience of moderate bedding affects behaviour of growing pigs

Effects of early substrate-enrichment on behaviour and productivity of pigs were evaluated in a trial with four siblings as the experimental unit. Pens either were (=E) or were not (=0) moderately bedded with wood shavings and chopped straw during suckling (0–4 weeks of age), nursery (5–9 weeks) and fattening stages (10–24 weeks). Accordingly, treatments were 1) 000 (n = 7); 2) E00 (n = 9); 3) EE0 (n = 9); 4) 00E (n = 10); 5) 0EE (n = 10) and 6) EEE (n = 9). Animals were videotaped in weeks 5, 9, 10, 14 and 21. Agonistic and explorative behaviours were recorded continuously for 3 × 10 min, and time budgets scan sampled for 24 h. Clinical post-weaning diarrhoea (PWD) was recorded daily for 18 days, and occurrence of body lesions weekly throughout the experiment to calculate severity-based skin (SLI), ear (ELI) and tail lesion indices (TLI). Behavioural effects of current environment were scarce. Bedding increased SLI and TLI in the nursery (P = 0.01 and 0.05, respectively), and decreased TLI in the fattening unit (P = 0.01). Experience of pre-weaning enrichment decreased the number of agonistic encounters at 14 weeks (P = 0.04). Experience of loss of enrichment increased fattening stage TLI (P = 0.003), and caused redirection of exploration towards pen fixtures in the fattening unit (P ≤ 0.03). Enrichment decreased the number of PWD days (P = 0.03), and increased feed intake and average daily gain between 7 and 9 weeks of age (P < 0.05). In conclusion, moderate bedding of farrowing pens seems to reduce agonistic behaviour later in life, although removal of it may increase redirected behaviour, including tail biting. Bedding may enhance productivity in weanling pigs.