Assessment of the behavioural performance of growing pigs under different enrichment strategies in the context of implementing animal welfare regulations in Ukraine

The strengthening of animal welfare requirements in Ukraine necessitates the adaptation of pig housing technologies to European integration standards. The study aimed to assess the impact of different environmental enrichment strategies on the play behaviour of growing pigs under industrial conditions. The experiment was conducted on four groups of pigs, each consisting of 22 individuals, aged 28 days at the start, with identical feeding and housing conditions. Enrichment objects were introduced before the start of video monitoring to ensure animal adaptation. Behavioural observations were carried out in three periods: days 29-35, 50-56, and 70-76. Data analysis was performed using two-way analysis of variance with fixed factors “group” and “day,” as well as their interaction “group × day.” The results showed that the “group” factor accounted for 51.7% of the variation in the first period, and in periods 2 and 3, it reached 99% ( P < 0.001). The duration of play behaviour in the control group ranged from 6.7 to 12.6 minutes, while in the group with a cotton rope, it was up to 42.7 minutes; in the group with bundles of packing paper, up to 65.2 minutes; and in the group with bottles partially filled with grain, up to 76.2 minutes. The results obtained for all periods of the study indicate that the “group” factor explained 78.0% of the total variation in play behaviour, while the “experiment period” explained only 5.0%, and unorganised factors accounted for 14.5%, indicating the clear dominance of enrichment type over time-related changes. Hierarchical variance analysis confirmed that in all groups, both the period and the day of the experiment had a highly significant impact (all P < 0.001), but the proportion of variation due to unorganised factors was highest in the growing piglets of the control group, at 53.6%. These data suggest a significant stimulatory effect of environmental enrichment on pig activity. The advantage of the enriched groups demonstrates the potential for improving the behavioural and emotional components of animal welfare. It is emphasised that the implementation of accessible and effective enrichment strategies is of practical importance for modernising pig housing in Ukraine in line with welfare requirements