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Objective: This study presents a novel quick in-pen “laser test” to assess piglet personality traits while minimizing environmental and handling interferences, aiming to identify behavioral consistency and potential novel traits.
Methods: A total of 120 weaned piglets were tested at 34, 54, and 65 days of age. In the laser test, a red laser light was directed 10 cm from the piglet’s snout for 10 s, followed by 20 s of observation. The observed behaviors included attention towards the laser, and exploration, walking, eating, drinking, laying, attention to others, vigilance, interaction with piglet and interaction with enrichment after the laser. Open field and novel object tests were also conducted at 60 and 61 days of age. Behavioral consistency across the laser test sessions were evaluated using correlation tests, and personality traits were identified via Principal Component Analysis (PCA). The behaviors from all three tests were included in the PCA.
Results: Piglets showed variability in their attention to the laser and subsequent exploration. The laser and novel object tests were correlated (laser attention, duration and frequency of interaction), but not laser and open field tests. PCA revealed three components explaining 62.4 % of behavioral variance: the first (23.7 %) reflected some behaviors observed in the laser and novel object tests, which loaded together (“curious” animals), the second (22.1 %) indicated cautious open field exploration (“fearful” animals), and the third (17.6 %) captured laser-specific responses (“cautious” animals).
Conclusion: The laser test offers a promising alternative to the novel object test, potentially revealing novel behavioral traits.
Gabriel K.C. Nakamura, Isabela C.C. Bez, Beatriz S. Souza, Heather W. Neave, Leandro B. Costa, Ruan R. Daros. Assessing pig personality in the home pen: a novel laser test. Applied Animal Behaviour Science, Volume 292, 2025, 106777. https://doi.org/10.1016/j.applanim.2025.106777