Dairy Heifer Motivation for Access to a Shaded Area

We used an operant conditioning paradigm to test the motivation of non-pregnant dairy heifers to access shade during the summer and autumn months (January to June) in southern Brazil. Dairy heifers (<i>n</i> = 18) were trained to push a weighted gate to access either an experimental area...

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Main Authors: Clarissa Silva Cardoso, Marina A. G. von Keyserlingk, Luiz Carlos Pinheiro Machado Filho, Maria José Hötzel
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Animals
Subjects:
Online Access:https://www.mdpi.com/2076-2615/11/9/2507
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author Clarissa Silva Cardoso
Marina A. G. von Keyserlingk
Luiz Carlos Pinheiro Machado Filho
Maria José Hötzel
author_facet Clarissa Silva Cardoso
Marina A. G. von Keyserlingk
Luiz Carlos Pinheiro Machado Filho
Maria José Hötzel
author_sort Clarissa Silva Cardoso
collection DOAJ
description We used an operant conditioning paradigm to test the motivation of non-pregnant dairy heifers to access shade during the summer and autumn months (January to June) in southern Brazil. Dairy heifers (<i>n</i> = 18) were trained to push a weighted gate to access either an experimental area containing both a shaded (simple tree shade and shade cloth) and unshaded area (WITH SHADE) or an experimental area with no shade (BARREN). The latency to push the weighted gate, and the maximum weight pushed by each heifer, were recorded in both the summer and the autumn. Temperature and humidity were recorded continuously for the duration of the study and were used to calculate the heat index. The maximum weight pushed to enter the WITH SHADE area was greater in summer than in autumn, and was inversely related to the latency to push the weighted gate. Heifers refused to work for access to the BARREN environment. As expected, both the maximum ambient temperatures and heat index were higher in summer than in autumn, and also higher in the non-shaded areas than under the shade in both seasons. Heifers of higher social rank displaced other heifers more often, and spent more time in the shaded areas, particularly in the area with trees plus a shade cloth, than the intermediate and subordinate heifers. We conclude that shade is an important and valued resource for heifers reared on pasture-based systems in sub-tropical environments, particularly during the hot summer months.
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spelling doaj.art-be07b82431094a10b717637f429c55772023-11-22T11:41:08ZengMDPI AGAnimals2076-26152021-08-01119250710.3390/ani11092507Dairy Heifer Motivation for Access to a Shaded AreaClarissa Silva Cardoso0Marina A. G. von Keyserlingk1Luiz Carlos Pinheiro Machado Filho2Maria José Hötzel3Laboratório de Etologia Aplicada e Bem-Estar Animal, Departamento de Zootecnia e Desenvolvimento Rural, Universidade Federal de Santa Catarina, Florianópolis 88034-001, BrazilAnimal Welfare Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC V6T 1Z4, CanadaLaboratório de Etologia Aplicada e Bem-Estar Animal, Departamento de Zootecnia e Desenvolvimento Rural, Universidade Federal de Santa Catarina, Florianópolis 88034-001, BrazilLaboratório de Etologia Aplicada e Bem-Estar Animal, Departamento de Zootecnia e Desenvolvimento Rural, Universidade Federal de Santa Catarina, Florianópolis 88034-001, BrazilWe used an operant conditioning paradigm to test the motivation of non-pregnant dairy heifers to access shade during the summer and autumn months (January to June) in southern Brazil. Dairy heifers (<i>n</i> = 18) were trained to push a weighted gate to access either an experimental area containing both a shaded (simple tree shade and shade cloth) and unshaded area (WITH SHADE) or an experimental area with no shade (BARREN). The latency to push the weighted gate, and the maximum weight pushed by each heifer, were recorded in both the summer and the autumn. Temperature and humidity were recorded continuously for the duration of the study and were used to calculate the heat index. The maximum weight pushed to enter the WITH SHADE area was greater in summer than in autumn, and was inversely related to the latency to push the weighted gate. Heifers refused to work for access to the BARREN environment. As expected, both the maximum ambient temperatures and heat index were higher in summer than in autumn, and also higher in the non-shaded areas than under the shade in both seasons. Heifers of higher social rank displaced other heifers more often, and spent more time in the shaded areas, particularly in the area with trees plus a shade cloth, than the intermediate and subordinate heifers. We conclude that shade is an important and valued resource for heifers reared on pasture-based systems in sub-tropical environments, particularly during the hot summer months.https://www.mdpi.com/2076-2615/11/9/2507operant conditioningbehaviourheat stressanimal welfaresocial rank
spellingShingle Clarissa Silva Cardoso
Marina A. G. von Keyserlingk
Luiz Carlos Pinheiro Machado Filho
Maria José Hötzel
Dairy Heifer Motivation for Access to a Shaded Area
Animals
operant conditioning
behaviour
heat stress
animal welfare
social rank
title Dairy Heifer Motivation for Access to a Shaded Area
title_full Dairy Heifer Motivation for Access to a Shaded Area
title_fullStr Dairy Heifer Motivation for Access to a Shaded Area
title_full_unstemmed Dairy Heifer Motivation for Access to a Shaded Area
title_short Dairy Heifer Motivation for Access to a Shaded Area
title_sort dairy heifer motivation for access to a shaded area
topic operant conditioning
behaviour
heat stress
animal welfare
social rank
url https://www.mdpi.com/2076-2615/11/9/2507
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AT mariajosehotzel dairyheifermotivationforaccesstoashadedarea