Complexity of behavioural sequences and their relation to stress conditions in chickens (Gallus gallus domesticus): a non-invasive technique to evaluate animal welfare

• DOI: 10.1016/j.applanim.2003.11.012
• Publication Date: 2004-02-07T10:16:00Z
• Authors: G.A. Marı́a; J. Escós; C.L. Alados
• Keywords: Gallus gallus domesticus; Locomotor activity; Animal Behavior

A complexity analysis was performed on the behaviour time series of four groups of seven chickens (Gallus gallus domesticus) using the detrended fluctuation analysis (DFA). DFA quantifies the fractal-like correlation properties of behaviour sequences on short time scales (seconds) over active periods of approximately 0.5 h (2050 s). In this study the level of randomization of locomotor and resting sequences was related to the rearing conditions of chickens. The complexity of locomotor sequences decreased with high stress (food limitation). Adding a sand substrate increased the complexity of other activities such as perching, foraging, and resting but reduced the complexity of locomotor behaviour due to the display of sand bath behaviour. In addition, the correspondence between the complexity of behaviour sequences and age was more pronounced under control situations than under stress (food limited). Under stress it appeared that there was not enough energy to perform complex adult behaviour.<br/>Peer reviewed<br/>The authors would like to acknowledge the assistance of Teresa Martı́ in the data recording from the videotapes and to Morris V. Robinson for the English review of the manuscript. This study was supported by research projects CICYT AGF97-0932 from the Spanish Ministry of Education and Science.<br/>