Use of infrared thermography to assess body temperature as a stress indicator on horses during ridden and lunging sessions

• Autor(a) principal: Martins, Joana de Noronha Araújo Rocha
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10348/11812
• topic: infrared thermography; welfare

As a sport, equitation is a cause of physiological stress in the equine athlete. Personality is a factor generally associated to the different responses of equines to stressors. Stress in horses has been measured through specific biomarkers, which includes body temperature, which recent work has shown the usefulness of infrared thermography (IRT) as a non-invasive tool to measure animal body temperature and correlated to workload and personality. This study explored ocular temperature measured by IRT associated to personality and stress in horses submitted to dressage exercising, in three modalities: riding lesson, ridden training and lunging. In this study, a total of 16 horses were tested on each modality on a semi-random order. Head IRT images were taken for each horse before and after the sessions, using a camera FLIR F4 (FLIR Systems AB, Sweden), and training time was registered. Fitting an ellipse to the eye using the FLIR Tools+ software tool, the maximum eye surface IRT temperature (IRTmax) was determined and subdivided into the means of pre (mIRTmax_b) and post (mIRTmax_a) workout. For personality assessment a novel stimuli test was conducted to generate 3 groups, and the ridden behaviour was scored every session with the focal observation method (mRBS). T was compared between modalities with a Kruskal-Wallis H test followed by a post hoc pairwise comparison. The variation of IRTmax pre and post workout within modalities was compared using Wilcoxon signed-rank test and between modalities with Kruskal-Wallis H test. IRTmax before exercise was tested between individuals with a Kruskal-Wallis H test. Wilcoxon signed-rank tests were ran for individual differences between before and after IRTmax. Then, DIF_IRTmax between individuals was tested with a Kruskal-Wallis H test. Correlations between mRBS and mIRTmax_a and groups were tested with Spearman Rank Correlation test, and sex and age groups with multiple comparisons followed by Kruskal-Wallis H tests with post hoc. Variances in mRBS between modalities was assessed using the Kruskal-Wallis H test. The mIRTmax_b between groups was assessed with Kruskal-Wallis H test. T was statistically different (p˂0,001), but no differences were found in IRTmax tests (p: 0,073 and p: 0,082), expect between individuals (p being the first to test dressage training in a familiar environment through IRT, further studies should be conducted to confirm the effectiveness of IRT in assessing dressage workload and ridden behaviour to design better fitness assessment tools.