Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep
Infrared thermography (IRT) has been recently applied to measure lacrimal caruncle temperature non-invasively since this region is related to the sympathetic response, and it seems a promising technique that is able to infer negative emotions in sheep (e.g., fear). However, the scientific literature...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/14/1/50 |
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| author | Marta Comin Elie Atallah Matteo Chincarini Silvia Michela Mazzola Elisabetta Canali Michela Minero Bruno Cozzi Emanuela Rossi Giorgio Vignola Emanuela Dalla Costa |
| author_facet | Marta Comin Elie Atallah Matteo Chincarini Silvia Michela Mazzola Elisabetta Canali Michela Minero Bruno Cozzi Emanuela Rossi Giorgio Vignola Emanuela Dalla Costa |
| author_sort | Marta Comin |
| collection | DOAJ |
| description | Infrared thermography (IRT) has been recently applied to measure lacrimal caruncle temperature non-invasively since this region is related to the sympathetic response, and it seems a promising technique that is able to infer negative emotions in sheep (e.g., fear). However, the scientific literature so far is limited in understanding whether a caruncle’s temperature changes also in response to positive emotional states in sheep. Through classical conditioning, we aimed to assess how a positive or a negative event affects the physiological (lacrimal caruncle temperature measured with IRT and cortisol levels) and behavioral responses of sheep (ear position). Fourteen ewes from the same flock were randomly assigned to two treatment groups: positive (<i>n</i> = 7) and negative (<i>n</i> = 7). Each group was then trained through classical conditioning to associate a neutral auditory (ring bell) stimulus to an oncoming event: for the positive group, the presence of a food reward (maize grains), while for the negative one, the opening of an umbrella. After three weeks of training, before (at rest) and after (post-treatment), lacrimal caruncle temperature was non-invasively measured via IRT, and saliva samples were gently collected to measure cortisol levels. During treatment, sheep behavior was videorecorded and then analyzed using a focal animal sampling technique. At rest, the eye’s lacrimal caruncle temperature was similar in both groups, while post-treatment, a significant increase was shown only in the negative group (<i>t</i>-test; <i>p</i> = 0.017). In the anticipation phase, sheep in the positive group kept their ears forward longer compared to those in the negative one (Mann–Whitney; <i>p</i> < 0.014), 8.3 ± 2.1 s and 5.2 ± 4.2 s, respectively. The behavioral response observed reflects a learnt association between a neutral stimulus and events with different emotional valence. Cortisol concentration slightly increased in both groups post-treatment. Our results confirm that IRT is a non-invasive technique that can be useful when applied to assess how positive and negative events may affect the physiological response in sheep. |
| first_indexed | 2024-03-08T15:12:12Z |
| format | Article |
| id | doaj.art-3c863b45c66645dc9fa3a7729d3aa874 |
| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-03-08T15:12:12Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj.art-3c863b45c66645dc9fa3a7729d3aa8742024-01-10T14:50:06ZengMDPI AGAnimals2076-26152023-12-011415010.3390/ani14010050Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in SheepMarta Comin0Elie Atallah1Matteo Chincarini2Silvia Michela Mazzola3Elisabetta Canali4Michela Minero5Bruno Cozzi6Emanuela Rossi7Giorgio Vignola8Emanuela Dalla Costa9Dipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyDipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyFacoltà di Medicina Veterinaria, Università degli Studi di Teramo, 64100 Teramo, ItalyDipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyDipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyDipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyDipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, 35131 Padova, ItalyIstituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise G. Caporale, 64100 Teramo, ItalyFacoltà di Medicina Veterinaria, Università degli Studi di Teramo, 64100 Teramo, ItalyDipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, 26900 Lodi, ItalyInfrared thermography (IRT) has been recently applied to measure lacrimal caruncle temperature non-invasively since this region is related to the sympathetic response, and it seems a promising technique that is able to infer negative emotions in sheep (e.g., fear). However, the scientific literature so far is limited in understanding whether a caruncle’s temperature changes also in response to positive emotional states in sheep. Through classical conditioning, we aimed to assess how a positive or a negative event affects the physiological (lacrimal caruncle temperature measured with IRT and cortisol levels) and behavioral responses of sheep (ear position). Fourteen ewes from the same flock were randomly assigned to two treatment groups: positive (<i>n</i> = 7) and negative (<i>n</i> = 7). Each group was then trained through classical conditioning to associate a neutral auditory (ring bell) stimulus to an oncoming event: for the positive group, the presence of a food reward (maize grains), while for the negative one, the opening of an umbrella. After three weeks of training, before (at rest) and after (post-treatment), lacrimal caruncle temperature was non-invasively measured via IRT, and saliva samples were gently collected to measure cortisol levels. During treatment, sheep behavior was videorecorded and then analyzed using a focal animal sampling technique. At rest, the eye’s lacrimal caruncle temperature was similar in both groups, while post-treatment, a significant increase was shown only in the negative group (<i>t</i>-test; <i>p</i> = 0.017). In the anticipation phase, sheep in the positive group kept their ears forward longer compared to those in the negative one (Mann–Whitney; <i>p</i> < 0.014), 8.3 ± 2.1 s and 5.2 ± 4.2 s, respectively. The behavioral response observed reflects a learnt association between a neutral stimulus and events with different emotional valence. Cortisol concentration slightly increased in both groups post-treatment. Our results confirm that IRT is a non-invasive technique that can be useful when applied to assess how positive and negative events may affect the physiological response in sheep.https://www.mdpi.com/2076-2615/14/1/50classical conditioningemotional statefearinfrared thermographynon-invasive measuresheep welfare |
| spellingShingle | Marta Comin Elie Atallah Matteo Chincarini Silvia Michela Mazzola Elisabetta Canali Michela Minero Bruno Cozzi Emanuela Rossi Giorgio Vignola Emanuela Dalla Costa Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep Animals classical conditioning emotional state fear infrared thermography non-invasive measure sheep welfare |
| title | Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep |
| title_full | Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep |
| title_fullStr | Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep |
| title_full_unstemmed | Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep |
| title_short | Events with Different Emotional Valence Affect the Eye’s Lacrimal Caruncle Temperature Changes in Sheep |
| title_sort | events with different emotional valence affect the eye s lacrimal caruncle temperature changes in sheep |
| topic | classical conditioning emotional state fear infrared thermography non-invasive measure sheep welfare |
| url | https://www.mdpi.com/2076-2615/14/1/50 |
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