{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:31:04Z","timestamp":1787027464062,"version":"build-2736575974"},"reference-count":62,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2016,1,7]],"date-time":"2016-01-07T00:00:00Z","timestamp":1452124800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Chicks require heat to maintain body temperature during the first weeks after hatch. This may be provided by dark brooders;  i.e. , horizontal heating elements equipped with curtains. The objective was to test effects of rearing layer chicks with dark brooders on time budget and fearfulness. Behavioral observations were performed during the first six weeks of age. Three different fear tests were conducted when the birds were age 3\u20136, 14\u201315 and 26\u201328 weeks. During the first four days, brooder chicks rested more than control chicks whereas they spent less time drinking, feather pecking and on locomotion ( p \u2264 0.009). On days 16, 23, 30 and 42, brooder chicks spent less time on feather pecking, locomotion and fleeing ( p \u2264 0.01) whereas foraging and dust bathing occurred more often on day 42 ( p \u2264 0.032). Brooder birds had shorter durations of tonic immobility at all ages ( p = 0.0032), moved closer to the novel object at age 15 weeks ( p &lt; 0.0001), and had shorter latencies to initiate locomotion in the open-field test at age 28 weeks ( p &lt; 0.0001). Results support the suggestion that dark brooders can be a successful method of reducing or preventing fear and feather pecking in layers.<\/jats:p>","DOI":"10.3390\/ani6010003","type":"journal-article","created":{"date-parts":[[2016,1,7]],"date-time":"2016-01-07T11:11:51Z","timestamp":1452165111000},"page":"3","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Effects of Dark Brooders on Behavior and Fearfulness in Layers"],"prefix":"10.3390","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8644-3456","authenticated-orcid":false,"given":"Anja","family":"Riber","sequence":"first","affiliation":[{"name":"Department of Animal Science, Faculty of Science and Technology, Aarhus University, Blichers All\u00e9 20, P.O. Box 50, Tjele DK-8830, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diego","family":"Guzman","sequence":"additional","affiliation":[{"name":"Instituto de Investigaciones Biol\u00f3gicas y Tecnol\u00f3gicas (CONICET-UNC) and Instituto de Ciencia y Tecnolog\u00eda de los Alimentos, Facultad de Ciencias Exactas, F\u00edsicas y Naturales, Universidad Nacional de C\u00f3rdoba, Av. V\u00e9lez Sarsfield 1611 (5000), C\u00f3rdoba X5016, Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,1,7]]},"reference":[{"key":"ref_1","first-page":"1023","article-title":"Ontogeny of heat production in chicks","volume":"28","author":"Weekstein","year":"1969","journal-title":"FASEB J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.applanim.2012.09.006","article-title":"The effect of dark brooders on feather pecking on commercial farms","volume":"142","author":"Gilani","year":"2012","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.applanim.2005.10.017","article-title":"Effect of brooders on feather pecking and cannibalism in domestic fowl (gallus gallus domesticus)","volume":"99","author":"Jensen","year":"2006","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1163\/156853981X00103","article-title":"Parental care and the development of thermoregulation in red junglefowl","volume":"76","author":"Sherry","year":"1981","journal-title":"Behaviour"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0003-3472(78)90001-5","article-title":"Simultaneous color discrimination in chicks is improved by brief exposure to light","volume":"26","author":"Cherfas","year":"1978","journal-title":"Anim. Behav."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1180","DOI":"10.1037\/h0077176","article-title":"Form preferences in successive discrimination-learning of young chicks","volume":"89","author":"Zolman","year":"1975","journal-title":"J. Comp. Physiol. Psychol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1037\/0097-7403.1.2.158","article-title":"Autoshaping chicks with heat reinforcement\u2014Role of stimulus-reinforcer and response-reinforcer relations","volume":"1","author":"Wasserman","year":"1975","journal-title":"J. Exp. Psychol. Anim. Behav. Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1016\/j.applanim.2007.01.001","article-title":"Diurnal activity cycles and synchrony in layer hen chicks (gallus gallus domesticus)","volume":"108","author":"Riber","year":"2007","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1016\/0003-3472(77)90109-9","article-title":"Parental food-calling and the role of the young in burmese red junglefowl (gallus gallus spadiceus)","volume":"25","author":"Sherry","year":"1977","journal-title":"Anim. Behav."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"21","DOI":"10.2307\/4083958","article-title":"Parental and courtship feeding in red jungle fowl","volume":"88","author":"Stokes","year":"1971","journal-title":"Auk"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1046\/j.1439-0310.2002.00793.x","article-title":"Maternal influences on feeding and general activity in domestic chicks","volume":"108","author":"Wauters","year":"2002","journal-title":"Ethology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.applanim.2006.07.012","article-title":"Effects of broody hens on perch use, ground pecking, feather pecking and cannibalism in domestic fowl (gallus gallus domesticus)","volume":"106","author":"Riber","year":"2007","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.applanim.2010.06.011","article-title":"Effect of broody hens on behaviour of chicks","volume":"126","author":"Shimmura","year":"2010","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/S0168-1591(01)00189-7","article-title":"Influence of mothering on emotional and social reactivity of domestic pullets","volume":"75","author":"Perre","year":"2002","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/S0168-1591(97)00073-7","article-title":"A comparison of the behaviour of domestic chicks reared with or without a hen in enriched pens","volume":"55","author":"Roden","year":"1998","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1017\/S096272860000083X","article-title":"The effects of selection on low mortality and brooding by a mother hen on open-field response, feather pecking and cannibalism in laying hens","volume":"18","author":"Rodenburg","year":"2009","journal-title":"Anim. Welf."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1111\/asj.12253","article-title":"Persistent effect of broody hens on behaviour of chickens","volume":"86","author":"Shimmura","year":"2015","journal-title":"Anim. Sci. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/0304-3762(78)90112-8","article-title":"Differences in agressiveness between brooded and non-brooded domestic chicks","volume":"4","year":"1978","journal-title":"Appl. Anim. Ethol."},{"key":"ref_19","unstructured":"Oester, H., and Wyss, C. (,  2001). Effect of Brooder Quality on the Early Development of Feather Pecking Behaviour in Domestic Chicks. Proceedings of the 6th European Symposium on Poultry Welfare, Zollikofen, Switzerland."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Riber, A.B. (2015). Effect of Dark Brooders on Fearfulness in Layers, Aarhus University.","DOI":"10.3390\/ani6010003"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1163\/156853974X00534","article-title":"Observational study of behavior: Sampling methods","volume":"49","author":"Altmann","year":"1974","journal-title":"Behaviour"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.beproc.2013.11.002","article-title":"When continuous observations just won\u2019t do: Developing accurate and efficient sampling strategies for the laying hen","volume":"103","author":"Daigle","year":"2014","journal-title":"Behav. Process."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1080\/00071660120070686","article-title":"Age-related changes in fear, sociality and pecking behaviours in two strains of laying hen","volume":"42","author":"Hocking","year":"2001","journal-title":"Br. Poult. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1079\/WPS19960013","article-title":"Fear and adaptability in poultry: Insights, implications and imperatives","volume":"52","author":"Jones","year":"1996","journal-title":"Worlds Poult. Sci. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.physbeh.2007.03.016","article-title":"A critical review of fear tests used on cattle, pigs, sheep, poultry and horses","volume":"92","author":"Forkman","year":"2007","journal-title":"Physiol. Behav."},{"key":"ref_26","unstructured":"Di Rienzo, J.A., Casanoves, F., Balzarini, M.G., Gonzalez, L., Tablada, M., and Robledo, C.W. (2015). Infostat, InfoStat versi\u00f3n 2015, InfoStat Group, National University of C\u00f3rdoba."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1198\/10857110260141193","article-title":"A multiple-comparisons method based on the distribution of the root node distance of a binary tree","volume":"7","author":"Guzman","year":"2002","journal-title":"JABES"},{"key":"ref_28","unstructured":"Riber, A.B. (2007). Ontogeny of Behaviour in Domestic Fowl\u2014With Emphasis on Feather Pecking. [Ph.D. Thesis, University of Copenhagen]."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1016\/0003-3472(64)90024-7","article-title":"A critical period in learning of motionless stimulus properties in chicks","volume":"12","author":"Brown","year":"1964","journal-title":"Anim. Behav."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1128","DOI":"10.1126\/science.146.3648.1128","article-title":"Imprinting in birds\u2014Research has borne out concept of imprinting as type of learning different from association learning","volume":"146","author":"Hess","year":"1964","journal-title":"Science"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1016\/0168-1591(95)00562-7","article-title":"The relative preferences for feathers, straw, wood-shavings and sand for dustbathing, pecking and scratching in domestic chicks","volume":"43","author":"Sanotra","year":"1995","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"133","DOI":"10.2754\/avb199665020133","article-title":"Pecking and scratching in the development of dust perception in young chicks","volume":"65","author":"Vestergaard","year":"1996","journal-title":"Acta Vet. Brno"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/0031-9384(94)90210-0","article-title":"Fear of humans in japanese quail selected for low or high adrenocortical response","volume":"56","author":"Jones","year":"1994","journal-title":"Physiol. Behav."},{"key":"ref_34","first-page":"1","article-title":"Ontogeny of social behaviour in burmase red junglefowl (gallus gallus spadiceus) bonnaterre","volume":"Suppl XII","author":"Kruijt","year":"1964","journal-title":"Behaviour"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.applanim.2006.06.017","article-title":"The importance of rest in young domestic fowl","volume":"106","author":"Malleau","year":"2007","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.applanim.2009.02.003","article-title":"Behavioural time budgets of broiler chickens reared in varying light intensities","volume":"118","author":"Alvino","year":"2009","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"20","DOI":"10.3382\/ps.2008-00177","article-title":"The effect of light intensity on the behavior, eye and leg health, and immune function of broiler chickens","volume":"88","author":"Blatchford","year":"2009","journal-title":"Poult. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1455","DOI":"10.1093\/ps\/80.10.1455","article-title":"Behavior of the domestic fowl in the presence of vertical panels","volume":"80","author":"Cornetto","year":"2001","journal-title":"Poult. Sci."},{"key":"ref_39","first-page":"81","article-title":"Domestic fowl - strategies to confront environmental conditions","volume":"11","author":"Yahav","year":"2000","journal-title":"Avian Poult. Biol. Rev."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1166","DOI":"10.1093\/ps\/84.8.1166","article-title":"Thermoregulation responses of broiler chickens to humidity at different ambient temperatures. I. One week of age","volume":"84","author":"Lin","year":"2005","journal-title":"Poult. Sci."},{"key":"ref_41","first-page":"111","article-title":"Evaporative heat-loss at high relative air humidity in poultry","volume":"55","author":"Nichelmann","year":"1991","journal-title":"Arch. Geflugelkd."},{"key":"ref_42","unstructured":"Riber, A.B., and Guzman, D.A. Effects of rearing with dark brooders on welfare and production in layers, Manuscript in preparation."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/0168-1591(86)90040-7","article-title":"Feather-pecking in poultry: Its relation with ground-pecking","volume":"16","author":"Blokhuis","year":"1986","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/0168-1591(89)90080-4","article-title":"The effect of a sudden change in floor type on pecking behaviour in chicks","volume":"22","author":"Blokhuis","year":"1989","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1006\/anbe.1996.0506","article-title":"Feather pecking in domestic chicks: Its relation to dustbathing and foraging","volume":"54","author":"Wechsler","year":"1997","journal-title":"Anim. Behav."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1006\/anbe.1997.0715","article-title":"The effect of quality and availability of foraging materials on feather pecking in laying hen chicks","volume":"55","author":"Wechsler","year":"1998","journal-title":"Anim. Behav."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1127","DOI":"10.1006\/anbe.1993.1137","article-title":"Feather pecking and chronic fear in groups of red junglefowl: Their relation to dustbathing, rearing environment and social status","volume":"45","author":"Vestergaard","year":"1993","journal-title":"Anim. Behav."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1163\/156853993X00146","article-title":"A model of feather pecking development which relates to dustbathing in the fowl","volume":"126","author":"Vestergaard","year":"1993","journal-title":"Behaviour"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1016\/0304-3762(82)90061-X","article-title":"Dust-bathing in the domestic fowl\u2014Diurnal rhytm and dust deprivation","volume":"8","author":"Vestergaard","year":"1982","journal-title":"Appl. Anim. Ethol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"753","DOI":"10.1046\/j.1439-0310.2001.00703.x","article-title":"Effects of resource allocation on behavioural strategies: A comparison of red junglefowl (gallus gallus) and two domesticated breeds of poultry","volume":"107","author":"Jensen","year":"2001","journal-title":"Ethology"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1080\/00071669408417715","article-title":"Behavioral expression of laying hens in aviaries and cages\u2014Frequencies, time budgets and facility utilization","volume":"35","author":"Hansen","year":"1994","journal-title":"Br. Poult. Sci."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1080\/00071669508417798","article-title":"Open-field and tonic immobility responses in domestic chicks of two genetic lines differing in their propensity to feather peck","volume":"36","author":"Jones","year":"1995","journal-title":"Br. Poult. Sci."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1023\/B:BEGE.0000023646.46940.2d","article-title":"Genetic and phenotypic correlations between feather pecking and open-field response in laying hens at two different ages","volume":"34","author":"Rodenburg","year":"2004","journal-title":"Behav. Genet."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1080\/00071668.2011.639342","article-title":"Effect of low light and high noise on behavioural activity, physiological indicators of stress and production in laying hens","volume":"52","author":"Parker","year":"2011","journal-title":"Br. Poult. Sci."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.applanim.2004.06.004","article-title":"Mothers\u2019fear of human affects the emotional reactivity of young in domestic japanese quail","volume":"89","author":"Bertin","year":"2004","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Houdelier, C., Lumineau, S., Bertin, A., Guibert, F., de Margerie, E., Augery, M., and Richard-Yris, M.A. (2011). Development of fearfulness in birds: Genetic factors modulate non-genetic maternal influences. PLoS ONE.","DOI":"10.1371\/journal.pone.0014604"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1016\/j.anbehav.2013.01.026","article-title":"Effects of maternal experience on fearfulness and maternal behaviour in a precocial bird","volume":"85","author":"Pittet","year":"2013","journal-title":"Anim. Behav."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.applanim.2012.05.004","article-title":"The effect of maternal care and infrared beak trimming on development, performance and behavior of silver nick hens","volume":"140","author":"Angevaare","year":"2012","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.applanim.2010.09.017","article-title":"Fearfulness and feather damage in laying hens divergently selected for high and low feather pecking","volume":"128","author":"Rodenburg","year":"2010","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1016\/j.applanim.2007.03.008","article-title":"The novel object test as predictor of feather damage in cage-housed Rhode Island Red and White Leghorn laying hens","volume":"109","author":"Uitdehaag","year":"2008","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1080\/00071667208415981","article-title":"Influence of strain and environmental factors upon feather pecking and cannibalism in fowls","volume":"13","author":"Hughes","year":"1972","journal-title":"Br. Poult. Sci."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1606","DOI":"10.3382\/ps.0611606","article-title":"Effects of cage design and bird density on layers. 1: Productivity, feathering, and nervousness","volume":"61","author":"Ouart","year":"1982","journal-title":"Poult. Sci."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/6\/1\/3\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:17:25Z","timestamp":1760210245000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/6\/1\/3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,1,7]]},"references-count":62,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2016,1]]}},"alternative-id":["ani6010003"],"URL":"https:\/\/doi.org\/10.3390\/ani6010003","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,1,7]]}}}