1
|
Ferreira VHB, Lansade L, Calandreau L, Cunha F, Jensen P. Are domesticated animals dumber than their wild relatives? A comprehensive review on the domestication effects on animal cognitive performance. Neurosci Biobehav Rev 2023; 154:105407. [PMID: 37769929 DOI: 10.1016/j.neubiorev.2023.105407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/03/2023]
Abstract
Animal domestication leads to diverse behavioral, physiological, and neurocognitive changes in domesticated species compared to their wild relatives. However, the widely held belief that domesticated species are inherently less "intelligent" (i.e., have lower cognitive performance) than their wild counterparts requires further investigation. To investigate potential cognitive disparities, we undertook a thorough review of 88 studies comparing the cognitive performance of domesticated and wild animals. Approximately 30% of these studies showed superior cognitive abilities in wild animals, while another 30% highlighted superior cognitive abilities in domesticated animals. The remaining 40% of studies found similar cognitive performance between the two groups. Therefore, the question regarding the presumed intelligence of wild animals and the diminished cognitive ability of domesticated animals remains unresolved. We discuss important factors/limitations for interpreting past and future research, including environmental influences, diverse objectives of domestication (such as breed development), developmental windows, and methodological issues impacting cognitive comparisons. Rather than perceiving these limitations as constraints, future researchers should embrace them as opportunities to expand our understanding of the complex relationship between domestication and animal cognition.
Collapse
Affiliation(s)
- Vitor Hugo Bessa Ferreira
- IFM Biology, AVIAN Behavioural Genomics and Physiology group, Linköping University, 581 83 Linköping, Sweden; INRAE, CNRS, IFCE, Université de Tours, Centre Val de Loire UMR Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
| | - Léa Lansade
- INRAE, CNRS, IFCE, Université de Tours, Centre Val de Loire UMR Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Ludovic Calandreau
- INRAE, CNRS, IFCE, Université de Tours, Centre Val de Loire UMR Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Felipe Cunha
- IFM Biology, AVIAN Behavioural Genomics and Physiology group, Linköping University, 581 83 Linköping, Sweden
| | - Per Jensen
- IFM Biology, AVIAN Behavioural Genomics and Physiology group, Linköping University, 581 83 Linköping, Sweden.
| |
Collapse
|
2
|
Li G, Li B, Shi Z, Lu G, Chai L, Rasheed KM, Regmi P, Banakar A. Interindividual distances and orientations of laying hens under 8 stocking densities measured by integrative deep learning techniques. Poult Sci 2023; 102:103076. [PMID: 37742450 PMCID: PMC10520532 DOI: 10.1016/j.psj.2023.103076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/20/2023] [Accepted: 08/25/2023] [Indexed: 09/26/2023] Open
Abstract
Interindividual distances and orientations of laying hens provide quantitative measures to calculate and optimize space allocations for bird flocks. However, these metrics were often measured manually and have not been examined for different stocking densities of laying hens. The objectives of this study were to 1) integrate and develop several deep learning techniques to detect interindividual distances and orientations of laying hens; and 2) examine the 2 metrics under 8 stocking densities via the developed techniques. Laying hens (Jingfen breed, a popular hen breed in China) at 35 wk of age were raised in experimental compartments at 8 different stocking densities of 3,840, 2,880, 2,304, 1,920, 1,646, 1,440, 1,280, and 1,152 cm2•bird-1 (3-10 hens per compartment, respectively), and cameras on the top of the compartments recorded videos for further analysis. The designed deep learning image classifier achieved over 99% accuracy to classify bird's perching status and excluded frames with bird perching to ensure that all birds analyzed were on the same horizontal plane, reducing calculation errors. The YOLOv5m oriented object detection model achieved over 90% precision, recall, and F1 score in detecting birds in compartments and can output bird centroid coordinates and angles, from which interindividual distances and orientations were calculated based on pairs of birds. Laying hens maintained smaller minimum interindividual distances in higher stocking densities. They were in an intersecting relationship with conspecifics for over 90% of the time. The developed integrative deep learning techniques and behavior metrics provide animal-based measurement of space requirement for laying hens.
Collapse
Affiliation(s)
- Guoming Li
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA; Institute for Artificial Intelligence, The University of Georgia, Athens, GA 30602, USA.
| | - Baoming Li
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, Beijing 100083, China
| | - Zhengxiang Shi
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, Beijing 100083, China
| | - Guoyu Lu
- Institute for Artificial Intelligence, The University of Georgia, Athens, GA 30602, USA; School of Electrical and Computer Engineering, The University of Georgia, Athens, GA 30602, USA
| | - Lilong Chai
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
| | - Khaled M Rasheed
- Institute for Artificial Intelligence, The University of Georgia, Athens, GA 30602, USA
| | - Prafulla Regmi
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA; School of Computing, The University of Georgia, Athens, GA 30602, USA
| | - Ahmad Banakar
- Biosystems Engineering Department, Tarbiat Modares University, Tehran 14117-13116, Iran
| |
Collapse
|
3
|
Verga L, Kotz SA, Ravignani A. The evolution of social timing. Phys Life Rev 2023; 46:131-151. [PMID: 37419011 DOI: 10.1016/j.plrev.2023.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 07/09/2023]
Abstract
Sociality and timing are tightly interrelated in human interaction as seen in turn-taking or synchronised dance movements. Sociality and timing also show in communicative acts of other species that might be pleasurable, but also necessary for survival. Sociality and timing often co-occur, but their shared phylogenetic trajectory is unknown: How, when, and why did they become so tightly linked? Answering these questions is complicated by several constraints; these include the use of divergent operational definitions across fields and species, the focus on diverse mechanistic explanations (e.g., physiological, neural, or cognitive), and the frequent adoption of anthropocentric theories and methodologies in comparative research. These limitations hinder the development of an integrative framework on the evolutionary trajectory of social timing and make comparative studies not as fruitful as they could be. Here, we outline a theoretical and empirical framework to test contrasting hypotheses on the evolution of social timing with species-appropriate paradigms and consistent definitions. To facilitate future research, we introduce an initial set of representative species and empirical hypotheses. The proposed framework aims at building and contrasting evolutionary trees of social timing toward and beyond the crucial branch represented by our own lineage. Given the integration of cross-species and quantitative approaches, this research line might lead to an integrated empirical-theoretical paradigm and, as a long-term goal, explain why humans are such socially coordinated animals.
Collapse
Affiliation(s)
- Laura Verga
- Comparative Bioacoustic Group, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands; Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.
| | - Sonja A Kotz
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Andrea Ravignani
- Comparative Bioacoustic Group, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands; Center for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| |
Collapse
|
4
|
Gjøen J, Cunha F, Jensen P. Selection for Reduced Fear of Humans Changes Brain and Cerebellum Size in Red Junglefowl in Line with Effects of Chicken Domestication. Brain Sci 2023; 13:988. [PMID: 37508920 PMCID: PMC10377726 DOI: 10.3390/brainsci13070988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
A central part of the domestication syndrome is a reduction in relative brain size. In chickens, it has previously been shown that domesticated birds have smaller relative brain mass, but larger relative mass of cerebellum, compared to their ancestors, the Red Junglefowl. It has been suggested that tameness may drive the domestication syndrome, so we examined the relationship between brain characteristics and tameness in 31 Red Junglefowl from lines divergently selected during ten generations for tameness. Our focus was on the whole brain, cerebellum, and the remainder of the brain. We used the isotropic fractionator technique to estimate the total number of cells in the cerebellum and differentiate between neurons and non-neuronal cells. We stained the cell nuclei with DAPI and performed cell counting using a fluorescence microscope. NeuN immunostaining was used to identify neurons. The absolute and relative masses of the brains and their regions were determined through weighing. Our analysis revealed that birds selected for low fear of humans (LF) had larger absolute brain mass, but smaller relative brain mass, compared to those selected for high fear of humans (HF). Sex had a significant impact only on the absolute size of the cerebellum, not its relative size. These findings support the notion that selection for increased tameness leads to an enlargement of the relative size of cerebellum in chickens consistent with comparisons of domesticated and ancestral chickens. Surprisingly, the HF birds had a higher density of neurons in the cerebellum compared to the LF line, despite having a smaller cerebellum overall. These findings highlight the intricate relationship between brain structure and behavior in the context of domestication.
Collapse
Affiliation(s)
| | | | - Per Jensen
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (J.G.); (F.C.)
| |
Collapse
|
5
|
Bessa Ferreira VH, Dutour M, Oscarsson R, Gjøen J, Jensen P. Effects of domestication on responses of chickens and red junglefowl to conspecific calls: A pilot study. PLoS One 2022; 17:e0279553. [PMID: 36584172 PMCID: PMC9803126 DOI: 10.1371/journal.pone.0279553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/09/2022] [Indexed: 12/31/2022] Open
Abstract
Beyond physical and zootechnical characteristics, the process of animal domestication has also altered how domesticated individuals, compared to their wild counterparts, perceive, process, and interact with their environment. Little is known, however, on whether and how domestication altered the perception of conspecific calls on both domesticated and wild breeds. In the present work, we compared the vigilance behavior of domestic and captive-born wild fowl following the playback of chicken alarm calls and contentment calls (control). The playback tests were performed on four different breeds/lines. We first compared the behavioral reaction of domesticated White Leghorn (WL, a breed selected for egg production) and Red Junglefowl (RJF) hens (ancestor of domestic chickens). We also compared the behavior of Red Junglefowl hens selected for high or low fear of humans (RJF HF and RJF LF, respectively), a proxy to investigate early effects of domestication. Contrary to our expectations, no breed/line reacted accordingly to the calls, as the increase in vigilance behavior after the playback calls was similar for both alarm and contentment calls. Although no call discrimination differences were found, breeds did differ on how they reacted/habituated to the calls. Overall, WL were more vigilant than RJF, and birds from the RJF LF line decreased their vigilance over testing days, while this was not the case for the RJF HF line. These results suggest that birds under commercial-like conditions are unable to discriminate between alarm and contentment calls. Interestingly, domestication and selection for low fear of humans may have altered how birds react to vocal stimuli. It is important to consider that farmed animals may interpret and be affected by the vocalizations of their conspecifics in unexpected ways, which warrants further investigation.
Collapse
Affiliation(s)
- Vitor Hugo Bessa Ferreira
- IFM Biology, AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden,* E-mail: (PJ); (VHBF)
| | - Mylène Dutour
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
| | - Rebecca Oscarsson
- IFM Biology, AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Johanna Gjøen
- IFM Biology, AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Per Jensen
- IFM Biology, AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden,* E-mail: (PJ); (VHBF)
| |
Collapse
|
6
|
Domestication effects on social information transfer in chickens. Anim Cogn 2022; 25:1473-1478. [PMID: 35507205 PMCID: PMC9652291 DOI: 10.1007/s10071-022-01628-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 03/30/2022] [Accepted: 04/17/2022] [Indexed: 11/28/2022]
Abstract
Red junglefowl (RJF), ancestor of all domesticated chickens, is a highly social, omnivorous bird species, presumably with a capacity for social information sharing. During domestication, birds have been selected to live in large, dynamic groups, and this may have affected their social cognition. Here, we studied social information transfer in female RJF and domesticated White Leghorn (WL) chickens. Individuals were trained to open a puzzle-box feeder by pecking a lid and we then recorded the behaviour towards the same puzzle-box feeder for birds that had either observed the trained individual (“guided”) or saw the puzzle-box feeder for the first time (“naïve”). WL were considerably faster in approaching the feeder regardless of prior demonstration and pecked more at it. Both breeds were significantly faster to approach the puzzle-box feeder and pecked more after prior demonstration, but the effects were significantly stronger in WL. We conclude that both RJF and WL can utilize social information to address a novel problem, but during domestication this ability appears to have increased. The effects can be an effect of either social learning or stimulus enhancement. Some caution in this conclusion is necessary since we tested relatively few WL. Furthermore, possible confounding explanations include higher fearfulness in RJF and different effects of dominance interactions between demonstrators and observers.
Collapse
|
7
|
Gjøen J, Jensen P. Selection for Reduced Fear of Humans Changes Intra-Specific Social Behavior in Red Junglefowl—Implications for Chicken Domestication. Genes (Basel) 2021; 13:genes13010043. [PMID: 35052386 PMCID: PMC8774865 DOI: 10.3390/genes13010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/03/2022] Open
Abstract
The domestic fowl has a different social behavior compared to their ancestor, the red junglefowl. To examine whether selection for tameness has affected their intra-specific social behavior, 32 red junglefowl from two selection lines, one selected for increased tameness and one selected for a high fear of humans for ten generations, were kept in a group of two females and two males each and were observed in a semi-natural undisturbed enclosure. Birds selected for a low fear of humans had more social conflict, and the males from this selection crowed more and were more often observed in low social proximity to others. The high-fear birds spent more time close together with the rest of the group and performed more social, non-aggressive pecking. These results are consistent with known differences between ancestral red junglefowl and domesticated laying hens. Our results show that intra-specific social behavior has been affected as a side-effect of selection for increased tameness. This may have interesting implications for the emergence of the domestication syndrome in chickens.
Collapse
|
8
|
Göransson L, Gunnarsson S, Wallenbeck A, Yngvesson J. Behaviour in Slower-Growing Broilers and Free-Range Access on Organic Farms in Sweden. Animals (Basel) 2021; 11:2967. [PMID: 34679986 PMCID: PMC8532691 DOI: 10.3390/ani11102967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 12/14/2022] Open
Abstract
Two slower-growing hybrids (Rowan Ranger and Hubbard) are currently reared in organic broiler production in Sweden, but knowledge of bird welfare on commercial farms is limited. This study examined chicken behaviour, including free-range use and features of this, in order to enhance knowledge, describe the current situation and identify practical solutions on Swedish organic broiler farms. Eight of 12 available farms were visited once each, when average flock age was 55 ± 6 days. Farmer interviews were followed by avoidance distance tests, group behavioural observations, and assessment of use of environmental enrichment and free-range by the chickens. On average, almost half of all birds observed indoors were in a sitting posture. However, even when approaching slaughter age, the chickens were agile enough to perch and used some of the variety of items provided for perching, but the quantity of environmental enrichment equipment appeared to be insufficient. Free-range areas generally lacked sufficient vegetation cover or artificial shelters, and chickens were predominantly observed ranging near the house. Further research should explore feasible ways for farmers to make key improvements to the indoor and outdoor environment, in order to improve broiler welfare.
Collapse
Affiliation(s)
- Lina Göransson
- Department of Animal Environment and Health, Swedish University of Agricultural Sciences (SLU), S-53223 Skara, Sweden; (S.G.); (A.W.); (J.Y.)
| | | | | | | |
Collapse
|
9
|
Anderson MG, Campbell AM, Crump A, Arnott G, Jacobs L. Environmental complexity positively impacts affective states of broiler chickens. Sci Rep 2021; 11:16966. [PMID: 34417475 PMCID: PMC8379235 DOI: 10.1038/s41598-021-95280-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/16/2021] [Indexed: 02/07/2023] Open
Abstract
Affective state can bias an animal's judgement. Animals in positive affective states can interpret ambiguous cues more positively ("optimistically") than animals in negative affective states. Thus, judgement bias tests can determine an animal's affective state through their responses to ambiguous cues. We tested the effects of environmental complexity and stocking density on affective states of broiler chickens through a multimodal judgement bias test. Broilers were trained to approach reinforced locations signaled by one color and not to approach unreinforced locations signaled by a different color. Trained birds were tested for latencies to approach three ambiguous cues of intermediate color and location. Broilers discriminated between cues, with shorter latencies to approach ambiguous cues closest to the reinforced cue than cues closest to the unreinforced cue, validating the use of the test in this context. Broilers housed in high-complexity pens approached ambiguous cues faster than birds in low-complexity pens-an optimistic judgement bias, suggesting the former were in a more positive affective state. Broilers from high-density pens tended to approach all cues faster than birds from low-density pens, possibly because resource competition in their home pen increased food motivation. Overall, our study suggests that environmental complexity improves broilers' affective states, implying animal welfare benefits of environmental enrichment.
Collapse
Affiliation(s)
- M. G. Anderson
- grid.438526.e0000 0001 0694 4940Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| | - A. M. Campbell
- grid.438526.e0000 0001 0694 4940Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| | - A. Crump
- grid.13063.370000 0001 0789 5319Centre for Philosophy of Natural and Social Science, London School of Economics and Political Science, London, UK
| | - G. Arnott
- grid.4777.30000 0004 0374 7521School of Biological Sciences, Queen’s University Belfast, Belfast, UK
| | - L. Jacobs
- grid.438526.e0000 0001 0694 4940Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| |
Collapse
|
10
|
Abstract
Although many factors affect the welfare of hens housed in cage and non-cage systems, welfare issues in cage systems often involve behavioural restrictions, whereas many welfare issues in non-cage systems involve health and hygiene. This review considers and compares the welfare of laying hens in cages, both conventional and furnished cages, with that of hens in non-cage systems, so as to highlight the welfare implications, both positive and negative, of cage housing. Comparisons of housing systems, particularly in commercial settings, are complex because of potentially confounding differences in physical, climatic and social environments, genetics, nutrition and management. Furthermore, some of the confounding factors are inherent to some specific housing systems. Nevertheless, research in commercial and experimental settings has indicated that hens in conventional and furnished cages have lower (or similar), but not higher, levels of stress on the basis of glucocorticoid concentrations than do hens in non-cage systems. Furthermore, caged hens, generally, have lower mortality rates than do hens in non-cage systems. However, the behavioural repertoire of laying hens housed in conventional cages is clearly more compromised than that of hens in non-cage systems. In contrast to conventional cages, furnished cages may provide opportunities for positive emotional experiences arising from perching, dust-bathing, foraging and nesting in a nest box. Some have suggested that the problems with modern animal production is not that the animals are unable to perform certain behavioural opportunities, but that they are unable to fill the extra time available with limited behaviours when they have no need to find food, water or shelter. Environmental enrichment in which objects or situations are presented that act successfully, and with a foreseeable rewarding outcome for hens by also providing regular positive emotional experience, is likely to enhance hen welfare. Research on cage systems highlights the importance of the design of the housing system rather than just the housing system per se.
Collapse
|
11
|
Perry WB, Solberg MF, Brodie C, Medina AC, Pillay KG, Egerton A, Harvey A, Creer S, Llewellyn M, Taylor M, Carvalho G, Glover KA. Disentangling the effects of sex, life history and genetic background in Atlantic salmon: growth, heart and liver under common garden conditions. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200811. [PMID: 33204455 PMCID: PMC7657880 DOI: 10.1098/rsos.200811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Livestock domestication has long been a part of agriculture, estimated to have first occurred approximately 10 000 years ago. Despite the plethora of traits studied, there is little understanding of the possible impacts domestication has had on internal organs, which are key determinants of survival. Moreover, the genetic basis of observed associated changes in artificial environments is still puzzling. Here we examine impacts of captivity on two organs in Atlantic salmon (Salar salar) that have been domesticated for approximately 50 years: heart and liver, in addition to growth. We studied multiple families of wild, domesticated, F1 and F2 hybrid, and backcrossed strains of S. salar in replicated common garden tanks during the freshwater and marine stages of development. Heart and liver weight were investigated, along with heart morphology metrics examined in just the wild, domesticated and F1 hybrid strains (heart height and width). Growth was positively linked with the proportion of the domesticated strain, and recombination in F2 hybrids (and the potential disruption of co-adapted gene complexes) did not influence growth. Despite the influence of domestication on growth, we found no evidence for domestication-driven divergence in heart or liver morphology. However, sexual dimorphism was detected in heart morphology, and after controlling for body size, females exhibited significantly larger heart weight and heart width when compared with males. Wild females also had an increased heart height when compared with wild males, and this was not observed in any other strain. Females sampled in saltwater showed significantly larger heart height with rounder hearts, than saltwater males. Collectively, these results demonstrate an additive basis of growth and, despite a strong influence of domestication on growth, no clear evidence of changes in heart or liver morphology associated with domestication was identified.
Collapse
Affiliation(s)
- William Bernard Perry
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Monica F. Solberg
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
| | - Christopher Brodie
- Mariani Molecular Ecology Laboratory, School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 5UX, UK
| | - Angela C. Medina
- School of Microbiology, Food Science and Technology Building University College Cork, Cork T12 TP07, Ireland
| | - Kirthana G. Pillay
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Anna Egerton
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Alison Harvey
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Martin Llewellyn
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Martin Taylor
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Gary Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Kevin A. Glover
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
- Institute of Biology, University of Bergen, Bergen, Norway
| |
Collapse
|
12
|
Ma H, Xu B, Li W, Wei F, Kim WK, Chen C, Sun Q, Fu C, Wang G, Li S. Effects of alpha-lipoic acid on the behavior, serum indicators, and bone quality of broilers under stocking density stress. Poult Sci 2020; 99:4653-4661. [PMID: 32988500 PMCID: PMC7598135 DOI: 10.1016/j.psj.2020.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 05/11/2020] [Accepted: 05/22/2020] [Indexed: 11/21/2022] Open
Abstract
The objective of present study was to investigate the effects of alpha-lipoic acid (ALA) dietary supplementation on the behavior, physiological and oxidant stress indicators, and bone quality in broilers under high stocking density (HSD) stress. A total of one thousand eight hundred 22-day-old Arbor Acres male broiler chicks were randomly allocated to 18 pens (2.97 × 2.03 m) in 3 groups: 14 birds/m2 (NSD, normal stocking density) or 18 birds/m2 (HSD) or 18 birds/m2 plus 300 mg/kg ALA dietary supplement (HSD + ALA, high stocking density + alpha-lipoic acid). Each treatment had 6 replicates, and the experiment lasted 3 wk. The HSD group was significantly lower than the NSD group (P < 0.05) in the frequency of eating, walking, and preening behavior. The alkaline phosphatase activity and serum calcium content were significantly higher, and the parathyroid hormone (PTH) level was significantly lower in the HSD group than in the NSD group (P < 0.05). When compared with the NSD group, the HSD group showed an increase (P < 0.05) in serum heterophil/lymphocyte ratio (H/L ratio), corticosterone (CORT), malondialdehyde (MDA) content, and catalase (CAT) activity, whereas a decrease (P < 0.05) in total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) concentrations. The HSD group was also significantly lower (P < 0.05) than the NSD group in the tibia and femur breaking strength, bone mineral density, and BMC. Importantly, the addition of ALA into the diets of the HSD group enabled the HSD + ALA group to recover to the levels of NSD group (P > 0.05) in the standing and preening behavior, alkaline phosphatase activity, PTH concentration, H/L ratio, CAT, T-AOC, MDA, SOD, and GSH-Px. These results indicate that the increase of stocking density lowered the bone quality, increased the physiological and oxidative stress indicators, and modified the behavior of broilers, whereas ALA dietary supplementation could counteract the reduction in the performance and physiological responses of broilers under high-density environmental stress.
Collapse
Affiliation(s)
- Huihui Ma
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Bin Xu
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Wenjia Li
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Fengxian Wei
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Woo Kyun Kim
- Department of Poultry Science, University of Georgia, Athens, GA 30602, USA
| | - Chongxiao Chen
- Department of Poultry Science, University of Georgia, Athens, GA 30602, USA
| | - Quanyou Sun
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Chen Fu
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Gaili Wang
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Shaoyu Li
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China.
| |
Collapse
|
13
|
|
14
|
|
15
|
Norman KI, Adriaense JEC, Nicol CJ. The impact of early structural enrichment on spatial cognition in layer chicks. Behav Processes 2019; 164:167-174. [PMID: 31077757 DOI: 10.1016/j.beproc.2019.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/08/2019] [Accepted: 05/07/2019] [Indexed: 12/30/2022]
Abstract
The aim of the study was to determine whether early access to elevated structures affects spatial navigational abilities. Ninety six day-old chicks were reared in 16 pens. Eight pens were provided with A-frame perches with an attached platform and a ramp. Eight pens had no elevated structures. At 14-15 days of age 48 chicks were tested in a battery of navigational tasks: a detour test, jump test and rotated floor test (RFT). The remaining 48 chicks received the same tests at 28-29 days of age. Chicks reared with elevated structures were faster at completing the detour test (P = 0.045). Older chicks were more likely to turn left in the detour test (p = 0.013) and were more successful in the jump test (69% vs 31% completion, p = 0.001). There was no treatment effect on use of intra or extra-maze cues in the RFT, but the proportion of chicks using intra-maze cues declined between the first (0.76) and second (0.43) repeat of the RFT (p = 0.038), particularly for chicks reared with elevated structures. We conclude that bird age or developmental stage may have a predominant influence on spatial navigation and physical ability, but early experience of elevated structures had some mediating effects which require further investigation.
Collapse
Affiliation(s)
- Kate I Norman
- Bristol Veterinary School, University of Bristol, Langford House, Bristol, BS40 5DU, UK.
| | - Jessie E C Adriaense
- Bristol Veterinary School, University of Bristol, Langford House, Bristol, BS40 5DU, UK; Department of Cognitive Biology, University of Vienna, Althanstrasse 14 (UZA1), 1090, Vienna, Austria; SCAN-Unit, Department of Basic Psychological Research and Research Methods, University of Vienna, Liebiggasse 5, 1010, Wien, Austria.
| | - Christine J Nicol
- Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, UK.
| |
Collapse
|
16
|
Using Radio-Frequency Identification Technology to Measure Synchronised Ranging of Free-Range Laying Hens. Animals (Basel) 2018; 8:ani8110210. [PMID: 30453521 PMCID: PMC6262442 DOI: 10.3390/ani8110210] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/22/2018] [Accepted: 11/13/2018] [Indexed: 12/01/2022] Open
Abstract
Simple Summary Free-range laying hens can choose to be indoors or outdoors. Individual hens vary in their ranging choice and this behaviour could also be affected by their flock mates. Radio-frequency identification tracking of individual hens in experimental free-range pens with group sizes of 46–50 hens was used to study flock ranging patterns. Across the day, hens moved through the range pop-holes in the same direction as other hens above levels expected by random chance, termed ‘pop-hole-following’. Hens were also simultaneously indoors or outdoors with other specific hens more often than expected by random chance, termed ‘hen-pair association’. Chicks that were provided variable stimulatory and structural enrichments from 4 to 21 days showed higher pop-hole-following and hen-pair association than non-enriched birds. The individual birds within these small hen groups were behaving primarily as a cohesive flock which has implications for understanding the group-level behaviour of hens. Further research would analyse if similar social movement patterns were present in larger commercial free-range flocks and how early rearing environments may affect adult social behaviour. Abstract Free-range laying hen systems provide individuals a choice between indoor and outdoor areas where range use may be socially influenced. This study used radio-frequency identification technology to track the ranging of individually-tagged hens housed in six experimental free-range pens from 28 to 38 weeks of age (46–50 hens/pen). All daily visits to the range were used to study group behaviour. Results showed that 67.6% (SD = 5.0%) of all hen movements through the pop-holes outdoors or indoors were following the movement of another hen (‘pop-hole-following’) compared to only 50.5% of movements in simulated random data. The percentage overlap in time that all combinations of hen pairs within each pen spent simultaneously outdoors or indoors showed a median value of overlap greater than the 90th percentile of random data. Pens housing hens that had been provided variable enrichments from 4 to 21 days (n = 3 pens) showed higher ‘pop-hole-following’ behaviour and a higher percentage of hen-pair association compared to hens reared in non-enriched conditions (n = 3 pens). These results show that birds in each free-range pen were primarily a cohesive flock and early enrichment improved this social cohesiveness. These results have implications for understanding free-range flock-level behaviour.
Collapse
|
17
|
|
18
|
Sophisticated Fowl: The Complex Behaviour and Cognitive Skills of Chickens and Red Junglefowl. Behav Sci (Basel) 2018; 8:bs8010013. [PMID: 29342087 PMCID: PMC5791031 DOI: 10.3390/bs8010013] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 01/08/2018] [Accepted: 01/12/2018] [Indexed: 01/09/2023] Open
Abstract
The world’s most numerous bird, the domestic chicken, and their wild ancestor, the red junglefowl, have long been used as model species for animal behaviour research. Recently, this research has advanced our understanding of the social behaviour, personality, and cognition of fowl, and demonstrated their sophisticated behaviour and cognitive skills. Here, we overview some of this research, starting with describing research investigating the well-developed senses of fowl, before presenting how socially and cognitively complex they can be. The realisation that domestic chickens, our most abundant production animal, are behaviourally and cognitively sophisticated should encourage an increase in general appraise and fascination towards them. In turn, this should inspire increased use of them as both research and hobby animals, as well as improvements in their unfortunately often poor welfare.
Collapse
|
19
|
Keeling LJ, Newberry RC, Estevez I. Flock size during rearing affects pullet behavioural synchrony and spatial clustering. Appl Anim Behav Sci 2017. [DOI: 10.1016/j.applanim.2017.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
20
|
|
21
|
Stress Induced Polarization of Immune-Neuroendocrine Phenotypes in Gallus gallus. Sci Rep 2017; 7:8102. [PMID: 28808318 PMCID: PMC5556001 DOI: 10.1038/s41598-017-08733-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/14/2017] [Indexed: 12/11/2022] Open
Abstract
Immune-neuroendocrine phenotypes (INPs) stand for population subgroups differing in immune-neuroendocrine interactions. While mammalian INPs have been characterized thoroughly in rats and humans, avian INPs were only recently described in Coturnix coturnix (quail). To assess the scope of this biological phenomenon, herein we characterized INPs in Gallus gallus (a domestic hen strain submitted to a very long history of strong selective breeding pressure) and evaluated whether a social chronic stress challenge modulates the individuals' interplay affecting the INP subsets and distribution. Evaluating plasmatic basal corticosterone, interferon-γ and interleukin-4 concentrations, innate/acquired leukocyte ratio, PHA-P skin-swelling and induced antibody responses, two opposite INP profiles were found: LEWIS-like (15% of the population) and FISCHER-like (16%) hens. After chronic stress, an increment of about 12% in each polarized INP frequency was found at expenses of a reduction in the number of birds with intermediate responses. Results show that polarized INPs are also a phenomenon occurring in hens. The observed inter-individual variation suggest that, even after a considerable selection process, the population is still well prepared to deal with a variety of immune-neuroendocrine challenges. Stress promoted disruptive effects, leading to a more balanced INPs distribution, which represents a new substrate for challenging situations.
Collapse
|
22
|
Lindholm C, Karlsson L, Johansson A, Altimiras J. Higher fear of predators does not decrease outdoor range use in free-range Rowan Ranger broiler chickens. ACTA AGR SCAND A-AN 2017. [DOI: 10.1080/09064702.2017.1337214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- C. Lindholm
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, Linköping, Sweden
| | - L. Karlsson
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, Linköping, Sweden
| | - A. Johansson
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, Linköping, Sweden
| | - J. Altimiras
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, Linköping, Sweden
| |
Collapse
|
23
|
Nordquist RE, van der Staay FJ, van Eerdenburg FJCM, Velkers FC, Fijn L, Arndt SS. Mutilating Procedures, Management Practices, and Housing Conditions That May Affect the Welfare of Farm Animals: Implications for Welfare Research. Animals (Basel) 2017; 7:E12. [PMID: 28230800 PMCID: PMC5332933 DOI: 10.3390/ani7020012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/15/2017] [Accepted: 02/15/2017] [Indexed: 12/26/2022] Open
Abstract
A number of mutilating procedures, such as dehorning in cattle and goats and beak trimming in laying hens, are common in farm animal husbandry systems in an attempt to prevent or solve problems, such as injuries from horns or feather pecking. These procedures and other practices, such as early maternal separation, overcrowding, and barren housing conditions, raise concerns about animal welfare. Efforts to ensure or improve animal welfare involve adapting the animal to its environment, i.e., by selective breeding (e.g., by selecting "robust" animals) adapting the environment to the animal (e.g., by developing social housing systems in which aggressive encounters are reduced to a minimum), or both. We propose adapting the environment to the animals by improving management practices and housing conditions, and by abandoning mutilating procedures. This approach requires the active involvement of all stakeholders: veterinarians and animal scientists, the industrial farming sector, the food processing and supply chain, and consumers of animal-derived products. Although scientific evidence about the welfare effects of current practices in farming such as mutilating procedures, management practices, and housing conditions is steadily growing, the gain in knowledge needs a boost through more scientific research. Considering the huge number of animals whose welfare is affected, all possible effort must be made to improve their welfare as quickly as possible in order to ban welfare-compromising procedures and practices as soon as possible.
Collapse
Affiliation(s)
- Rebecca E Nordquist
- Behavior & Welfare Group (Formerly Emotion & Cognition Group), Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3584CL, The Netherlands.
- Brain Center Rudolf Magnus, Universiteitsweg 100, Utrecht 3584CG, The Netherlands.
| | - Franz Josef van der Staay
- Behavior & Welfare Group (Formerly Emotion & Cognition Group), Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3584CL, The Netherlands.
- Brain Center Rudolf Magnus, Universiteitsweg 100, Utrecht 3584CG, The Netherlands.
| | - Frank J C M van Eerdenburg
- Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3584CL, The Netherland.
| | - Francisca C Velkers
- Epidemiology and Poultry Health Care, Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3584CL, The Netherlands.
| | - Lisa Fijn
- Behavior & Welfare Group (Formerly Emotion & Cognition Group), Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3584CL, The Netherlands.
- Brain Center Rudolf Magnus, Universiteitsweg 100, Utrecht 3584CG, The Netherlands.
| | - Saskia S Arndt
- Animal Welfare and Laboratory Animal Science, Department Animals in Science and Society, Faculty of Veterinary Medicine, University Utrecht, Utrecht 3508TD, The Netherlands.
| |
Collapse
|
24
|
Scheiber IBR, Weiß BM, Kingma SA, Komdeur J. The importance of the altricial - precocial spectrum for social complexity in mammals and birds - a review. Front Zool 2017; 14:3. [PMID: 28115975 PMCID: PMC5242088 DOI: 10.1186/s12983-016-0185-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 12/08/2016] [Indexed: 12/31/2022] Open
Abstract
Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems.
Collapse
Affiliation(s)
- Isabella B R Scheiber
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Brigitte M Weiß
- Behavioural Ecology Research Group, University of Leipzig, Faculty of Bioscience, Pharmacy and Psychology, Institute of Biology, Talstraße 33, 04103 Leipzig, Germany.,Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Sjouke A Kingma
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jan Komdeur
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| |
Collapse
|
25
|
Caubet Y, Richard FJ. NEIGHBOUR-IN: Image processing software for spatial analysis of animal grouping. Zookeys 2015; 515:173-89. [PMID: 26261448 PMCID: PMC4525043 DOI: 10.3897/zookeys.515.9390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/11/2015] [Indexed: 11/12/2022] Open
Abstract
Animal grouping is a very complex process that occurs in many species, involving many individuals under the influence of different mechanisms. To investigate this process, we have created an image processing software, called NEIGHBOUR-IN, designed to analyse individuals' coordinates belonging to up to three different groups. The software also includes statistical analysis and indexes to discriminate aggregates based on spatial localisation of individuals and their neighbours. After the description of the software, the indexes computed by the software are illustrated using both artificial patterns and case studies using the spatial distribution of woodlice. The added strengths of this software and methods are also discussed.
Collapse
Affiliation(s)
- Yves Caubet
- Université de Poitiers - Faculté des Sciences, UMR CNRS 7267 EBI – “Écologie, Évolution, Symbiose”, Bat. B8-B35; 6, rue Michel Brunet, TSA 51106, F-86073 POITIERS Cedex 9, France
| | - Freddie-Jeanne Richard
- Université de Poitiers - Faculté des Sciences, UMR CNRS 7267 EBI – “Écologie, Évolution, Symbiose”, Bat. B8-B35; 6, rue Michel Brunet, TSA 51106, F-86073 POITIERS Cedex 9, France
| |
Collapse
|
26
|
|
27
|
Ericsson M, Fallahsharoudi A, Bergquist J, Kushnir MM, Jensen P. Domestication effects on behavioural and hormonal responses to acute stress in chickens. Physiol Behav 2014; 133:161-9. [DOI: 10.1016/j.physbeh.2014.05.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 04/28/2014] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
|
28
|
Agnvall B, Jöngren M, Strandberg E, Jensen P. Heritability and genetic correlations of fear-related behaviour in Red Junglefowl--possible implications for early domestication. PLoS One 2012; 7:e35162. [PMID: 22536354 PMCID: PMC3334967 DOI: 10.1371/journal.pone.0035162] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 03/13/2012] [Indexed: 11/26/2022] Open
Abstract
Domesticated species differ from their wild ancestors in a number of traits, generally referred to as the domesticated phenotype. Reduced fear of humans is assumed to have been an early prerequisite for the successful domestication of virtually all species. We hypothesized that fear of humans is linked to other domestication related traits. For three generations, we selected Red Junglefowl (ancestors of domestic chickens) solely on the reaction in a standardized Fear of Human-test. In this, the birds were exposed for a gradually approaching human, and their behaviour was continuously scored. This generated three groups of animals, high (H), low (L) and intermediate (I) fearful birds. The birds in each generation were additionally tested in a battery of behaviour tests, measuring aspects of fearfulness, exploration, and sociality. The results demonstrate that the variation in fear response of Red Junglefowl towards humans has a significant genetic component and is genetically correlated to behavioural responses in other contexts, of which some are associated with fearfulness and others with exploration. Hence, selection of Red Junglefowl on low fear for humans can be expected to lead to a correlated change of other behavioural traits over generations. It is therefore likely that domestication may have caused an initial suite of behavioural modifications, even without selection on anything besides tameness.
Collapse
Affiliation(s)
- Beatrix Agnvall
- IFM Biology, Division of Zoology, Avian Behavioural Genomics and Physiology Group Linköping University, Linköping, Sweden
| | - Markus Jöngren
- IFM Biology, Division of Zoology, Avian Behavioural Genomics and Physiology Group Linköping University, Linköping, Sweden
| | - Erling Strandberg
- Department of Animal Breeding and Genetics, Swedish University of Agricultural, Sciences, Uppsala, Sweden
| | - Per Jensen
- IFM Biology, Division of Zoology, Avian Behavioural Genomics and Physiology Group Linköping University, Linköping, Sweden
- * E-mail:
| |
Collapse
|
29
|
|