Document type: scientific review published in Neuroscience & Biobehavioral Reviews
Authors: Chenyang Li, Jie Gao, Hang Shu, Guangyong Zhao, Xianhong Gu
Preview: Stereotypic behaviors, characterized by repetitive, fixed, and seemingly functionless behavioral patterns, are critical indicators of compromised animal welfare and neuropsychiatric disorders. While stereotypic behaviors have been extensively studied in humans and laboratory animals, the neurobiological mechanisms underlying these behaviors in farm animals and their cross-species commonalities remain to be systematically elucidated. This review summarizes the progress in research on stereotypic behaviors, with a particular focus on comparing the phenotypic similarities among humans, laboratory animals, and farm animals. It explores key biological principles underlying stereotypic behaviors, including imbalances in neurotransmitter systems, basal ganglia circuit dysfunction, and the modulatory effects of environmental enrichment. Although these mechanisms have been thoroughly investigated in humans and laboratory animals, corresponding evidence in farm animals remains limited. Furthermore, this paper systematically analyzes the current limitations in research on stereotypical behaviors in farm animals, such as the lack of standardized quantification tools, inconsistent phenotypic descriptions, high economic costs, and insufficient interdisciplinary communication. However, several emerging opportunities hold promise for future advancements, including the use of physiological and structural similarities across species for translational research, the application of computer vision, a focus on the potential regulatory mechanisms of the microbiome-gut-brain axis, and the integration of other advanced methods such as multi-omics and genetic marker screening. This review aims to provide new perspectives for a deeper understanding of the mechanisms underlying stereotypical behaviors in farm animals, offer a theoretical basis for developing precise behavioral welfare assessment and intervention strategies, and ultimately promote the advancement of farm animal welfare.
