Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness

Background One priority for animal welfare is for animals to experience less fear, especially during human contact. For domestic animals, breeds that are less fearful may provide genetic resources to develop strains with improved welfare due to lower susceptibility to fear. Genetic predispositions i...

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Main Authors: Inga Tiemann, Senta Becker, Jocelyn Fournier, Daalkhaijav Damiran, Wolfgang Büscher, Sonja Hillemacher
Format: Article
Language:English
Published: PeerJ Inc. 2023-04-01
Series:PeerJ
Subjects:
Online Access:https://peerj.com/articles/14703.pdf
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author Inga Tiemann
Senta Becker
Jocelyn Fournier
Daalkhaijav Damiran
Wolfgang Büscher
Sonja Hillemacher
author_facet Inga Tiemann
Senta Becker
Jocelyn Fournier
Daalkhaijav Damiran
Wolfgang Büscher
Sonja Hillemacher
author_sort Inga Tiemann
collection DOAJ
description Background One priority for animal welfare is for animals to experience less fear, especially during human contact. For domestic animals, breeds that are less fearful may provide genetic resources to develop strains with improved welfare due to lower susceptibility to fear. Genetic predispositions inherited in these breeds might reflect the large diversity of chicken breeds. The goal of the present study was to systematically test a diverse group of chicken breeds to search for breeds that experience less fear. Methods Nineteen chicken breeds from commercial hybrid lines, native layer-type, meat-type and dual-purpose breeds, ornamental breeds as well as bantam breeds were tested in a standardized tonic immobility (TI) test. Chickens were manually restrained on their back, and the time to first head movement and first leg movement, the duration of TI, as well as the number of attempts needed to induce TI were measured. Results The TI response differed among chicken breeds (p ≤ 0.001) for naïve, mature hens. The median number of attempts required to induce TI ranged from 1 to 2 and did not differ significantly among breeds. Median durations were much more variable, with Lohmann Brown showing shortest durations (6 s, 12 s, 58 s for time to first head movement, first leg movement and total duration of TI, respectively). In contrast, medians reached the maximum of 600 s for all three measures in German Creepers. Repeated tests on the same individuals did not affect attempts needed to induce TI nor TI durations. Breeds clustered into two main groups, with layer-type native breeds and ornamental breeds having longer TI durations, and bantam, dual-purpose and meat-type native breeds having shorter TI durations. Conclusions Our findings provide evidence for substantial variation of fearfulness among breeds. This variation could be linked to the intended use during the breed’s specific history. Knowledge and quantitative measurement of these behavioural responses provide the opportunity to improve welfare through selection and future breeding.
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spelling doaj.art-43a8ceddd5b345269b387b779640d5d22023-12-03T10:32:07ZengPeerJ Inc.PeerJ2167-83592023-04-0111e1470310.7717/peerj.14703Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulnessInga Tiemann0Senta Becker1Jocelyn Fournier2Daalkhaijav Damiran3Wolfgang Büscher4Sonja Hillemacher5Institute of Agricultural Engineering, University of Bonn, Bonn, GermanyInstitute of Agricultural Engineering, University of Bonn, Bonn, GermanyDepartment of Animal & Poultry Science, University of Saskatchewan, Saskatoon, CanadaDepartment of Animal & Poultry Science, University of Saskatchewan, Saskatoon, CanadaInstitute of Agricultural Engineering, University of Bonn, Bonn, GermanyInstitute of Agricultural Engineering, University of Bonn, Bonn, GermanyBackground One priority for animal welfare is for animals to experience less fear, especially during human contact. For domestic animals, breeds that are less fearful may provide genetic resources to develop strains with improved welfare due to lower susceptibility to fear. Genetic predispositions inherited in these breeds might reflect the large diversity of chicken breeds. The goal of the present study was to systematically test a diverse group of chicken breeds to search for breeds that experience less fear. Methods Nineteen chicken breeds from commercial hybrid lines, native layer-type, meat-type and dual-purpose breeds, ornamental breeds as well as bantam breeds were tested in a standardized tonic immobility (TI) test. Chickens were manually restrained on their back, and the time to first head movement and first leg movement, the duration of TI, as well as the number of attempts needed to induce TI were measured. Results The TI response differed among chicken breeds (p ≤ 0.001) for naïve, mature hens. The median number of attempts required to induce TI ranged from 1 to 2 and did not differ significantly among breeds. Median durations were much more variable, with Lohmann Brown showing shortest durations (6 s, 12 s, 58 s for time to first head movement, first leg movement and total duration of TI, respectively). In contrast, medians reached the maximum of 600 s for all three measures in German Creepers. Repeated tests on the same individuals did not affect attempts needed to induce TI nor TI durations. Breeds clustered into two main groups, with layer-type native breeds and ornamental breeds having longer TI durations, and bantam, dual-purpose and meat-type native breeds having shorter TI durations. Conclusions Our findings provide evidence for substantial variation of fearfulness among breeds. This variation could be linked to the intended use during the breed’s specific history. Knowledge and quantitative measurement of these behavioural responses provide the opportunity to improve welfare through selection and future breeding.https://peerj.com/articles/14703.pdfFearChickenAnimal genetic resourcesPoultryTonic immobilityAnimal welfare
spellingShingle Inga Tiemann
Senta Becker
Jocelyn Fournier
Daalkhaijav Damiran
Wolfgang Büscher
Sonja Hillemacher
Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
PeerJ
Fear
Chicken
Animal genetic resources
Poultry
Tonic immobility
Animal welfare
title Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
title_full Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
title_fullStr Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
title_full_unstemmed Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
title_short Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
title_sort differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness
topic Fear
Chicken
Animal genetic resources
Poultry
Tonic immobility
Animal welfare
url https://peerj.com/articles/14703.pdf
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