Multimodal Digital Sensing of Early-Life Laying Hens: A Pilot Study Integrating Thermal, Acoustic, Optical-Flow and Environmental Data

Early-life development strongly influences long-term welfare in laying hens, yet monitoring remains limited by subjective assessment and single-modality tools. This pilot study evaluated the feasibility of a multimodal sensing framework integrating thermal imaging, acoustic recording, optical-flow-based video analysis, and environmental monitoring to characterize physiological and behavioural development from hatch to 20 weeks. One hundred fifty Lohmann LSL-Lite chicks were housed across five controlled rooms; thermal and environmental data were collected system-wide, while detailed audio and video analyses focused on one representative room. Weekly aggregated features included head and foot surface temperatures, acoustic spectral descriptors, optical-flow movement responses to caretaker entry, and ambient conditions. Thermal imaging showed age-related increases and stabilization of peripheral temperatures, with foot temperature exhibiting a strong developmental effect (eta squared = 0.51). Acoustic features changed systematically across weeks (p < 0.001), consistent with vocal maturation. Optical-flow analysis revealed pronounced early reactivity to caretaker presence that declined with age (weeks 5 to 10 versus 11 to 20: t = 28.12, p = 0.00126). Z-score-normalized multimodal trajectories and correlation analysis (false discovery rate q < 0.05) showed strong within-modality consistency (r = 0.85 to 0.96) and selective associations between humidity and acoustic features (r = 0.65 to 0.70), while thermal, acoustic, and behavioural domains remained largely independent. This pilot establishes baseline multimodal developmental patterns and supports parallel sensing for welfare-relevant monitoring in precision poultry farming.