Fig 1.
Data collected at 5 weeks old (Restraint Test), 24 hours post-farrow (Litter Restraint Test), and, 1 hour (Social Interaction Test) and 2 weeks (Judgement Bias Test) post-mixing into group pen, as well how data collection corresponds to the life cycle of the sow.
Table 1.
Operational definition of each score given to sows during the litter handle test when their piglets were removed from pen during processing.
Table 2.
Ethogram of behaviors coded during the 1-hour post-introduction to an unfamiliar, dynamic gestation pen 5 days following weaning and breeding.
Fig 2.
Schematic representation of judgement bias experiment.
Sow was held behind gate at starting line (long dashed line). During training, the conditioned feed bowls were place in either far left or right location of the arena. Only one feed bowl was present at a time. Testing trials placed feed bowl in the ambiguous stimulus position (?), equidistant from rewarded (+) and punished (-) locations. Approach was defined as the latency for the sow to leave the starting gate and cross the goal line (short dashed line) with at least one front limb.
Table 3.
Obliquely rotated principal component loadings for behaviors recorded during the 1-hour post-introduction to an unfamiliar, dynamic pen as primiparous sows.
Fig 3.
Judgement bias outcomes vary across group housed sows.
Individual latencies for sows to approach the positive, ambiguous, and negative stimuli area displayed as well as means for animal exhibiting either an optimistic bias (ambiguous approach < 20 s), an undetermined bias (ambiguous approach, between 20-50s) or a pessimistic bias (ambiguous approach > 50 s). Both optimistic and pessimistic bias animals approach the positive and negative conditioned stimulus with similar latencies independent of their judgement bias.
Fig 4.
Personality influences judgement bias of gestating sows.
(A) Significant relationship between the trait scores for aggressive/dominant and the latency to approach the ambiguous cue (p = 0.003), with more aggressive/dominant sows approaching the ambiguous cue faster; indicative of a positive judgement bias. (B) Aggressive/dominant animals, however, do not approach the positive cue faster than less aggressive animals (p = 0.65).
Fig 5.
Physical measures of animal welfare do not predict with judgement bias of gestating sows.
(A) Significant relationship between anterior skin lesion scores and submissive trait scores (p = 0.013) as animals with more severe skin lesions had higher submissive trait scores. (B) Animals with less severe anterior lesions scores, and thus better physical welfare, did not exhibit faster approaches to the ambiguous cue as no significant relationship was observed between lesion scores and latency to approach the ambiguous cue (p = 0.699).