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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Microscopia Eletronica de varredura no estudo do desenvolvimento inicial do tecto optico do embrião Gallusdomesticus. / Scanning electron microscopy study of the initial development of the embryo optical roof of Gallus domesticus

Silva, Ciro Ferreira da 27 March 1981 (has links)
Diferentes técnicas e metodologias foram utilizadas no estudo do desenvolvimento do sistema nervoso, analisando como modelos experimentais, entre outros, o embrião do \"Gallus domesticus\" e embriões de diferentes anfíbios. Com o advento do microscópio eletrônico de varredura (M.E.V.) pode-se, com certas limitações, efetuar uma análise tridimensional de estruturas biológicas. Portanto, utilizando o M.E.V., neste trabalho apresentamos nossas observações sobre o desenvolvimento inicial do tecto óptico do embrião de \"Gallus domesticus. / Different techniques and methods were used in the study of the development of the nervous system, analyzing how experimental models, among others, the embryo of \"Gallus domesticus\" and embryos of different amphibians. With the advent of the scanning electron microscope (SEM) can be, with certain limitations, make an analysis of three-dimensional structures. Therefore, using the SEM, in this paper we present our observations on the initial development of the embryo optical roof of \"Gallus domesticus.
2

Microscopia Eletronica de varredura no estudo do desenvolvimento inicial do tecto optico do embrião Gallusdomesticus. / Scanning electron microscopy study of the initial development of the embryo optical roof of Gallus domesticus

Ciro Ferreira da Silva 27 March 1981 (has links)
Diferentes técnicas e metodologias foram utilizadas no estudo do desenvolvimento do sistema nervoso, analisando como modelos experimentais, entre outros, o embrião do \"Gallus domesticus\" e embriões de diferentes anfíbios. Com o advento do microscópio eletrônico de varredura (M.E.V.) pode-se, com certas limitações, efetuar uma análise tridimensional de estruturas biológicas. Portanto, utilizando o M.E.V., neste trabalho apresentamos nossas observações sobre o desenvolvimento inicial do tecto óptico do embrião de \"Gallus domesticus. / Different techniques and methods were used in the study of the development of the nervous system, analyzing how experimental models, among others, the embryo of \"Gallus domesticus\" and embryos of different amphibians. With the advent of the scanning electron microscope (SEM) can be, with certain limitations, make an analysis of three-dimensional structures. Therefore, using the SEM, in this paper we present our observations on the initial development of the embryo optical roof of \"Gallus domesticus.
3

Avaliação do endotélio da córnea de galinhas (Gallus gallus domesticus) em diferentes faixas etárias utilizando a microscopia especular

Freitas, Luciana Vicente Rosa Pacicco de January 2012 (has links)
O endotélio corneano é uma monocamada de células poligonais localizadas na face posterior da córnea e é essencial para a manutenção da transparência corneana. Não foram encontradas referências na literatura a respeito dos parâmetros morfológicos e morfométricos do endotélio da córnea de galinhas, apesar destes animais serem amplamente utilizados como modelo experimental em estudos oftálmicos, devido à similitude com a córnea de humanos. O objetivo deste estudo foi o de avaliar os parâmetros morfométricos e o pleomorfismo da região central do endotélio da córnea de galinhas (Gallus gallus domesticus) de diferentes faixas etárias, utilizando a microscopia especular de contato. Avaliaram-se a densidade, a área celular média e o pleomorfismo das células do endotélio da córnea de 60 olhos de 30 galinhas da raça Leghorn branca. Os animais foram divididos em três grupos composto por 10 animais cada: G1 (animais com 30 dias de idade), G2 (animais com 45 dias de idade) e G3 (animais com 60 dias de idade). O presente estudo revelou que o endotélio da córnea de galinhas é composto por células poligonais de padrão regular, com predomínio de formato hexagonal. O endotélio corneano de galinhas sofreu alterações decorrentes da idade no que tange a morfometria, mas no que diz respeito ao pleomorfismo, não ocorreram alterações em resposta ao envelhecimento. / The corneal endothelium is a monolayer of polygonal cells located on the posterior face of the cornea and it is essential for the maintenance of corneal transparency. We found no references in the literature concerning the morphological and morphometric parameters of the corneal endothelium of chickens, although these animals are widely used as experimental model in ophthalmic studies due to the similarity with the human cornea. The objective of this study was to evaluate the morphometric parameters and the pleomorphism of central corneal endothelium of chickens (Gallus gallus domesticus) of different ages using the contact specular microscopy. The density, the average cell area and the pleomorphism of the corneal endothelial cells were evaluated on 60 eyes of 30 white Leghorn chickens. The animals were divided into three groups of 10 animals each: G1 (animals with 30 days of age), G2 (animals with 45 days of age) and G3 (animals with 60 days of age). The present study revealed that the corneal endothelium of chickens is composed of regular polygonal cells, with predominance of hexagonal shape. The corneal endothelium of chickens has changed due to age in respect to morphometry, but in regard to pleomorphism, no changes occurred in response to aging.
4

Frequ?ncia da infec??o por Toxoplasma gondii em galinhas caipira e frangos de corte em regi?es dos Estados do Rio Grande do Norte e Para?ba

Santos, Maria Cec?lia Farias dos 11 June 2012 (has links)
Made available in DSpace on 2014-12-17T14:10:27Z (GMT). No. of bitstreams: 1 MariaCFS_DISSERT.pdf: 790525 bytes, checksum: c565e1057a72e1ddf23dec1d882788e8 (MD5) Previous issue date: 2012-06-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, a protozoan that has a cosmopolitan geographic distribution and low host specificity. Usually a benign and selflimiting, infection can manifest itself in a severe systemic becoming overwhelming in fetuses and patients with immunosuppression. Domestic fowl are considered one of the most important hosts in the epidemiology of toxoplasmosis, since they are potential sources of infection for humans, in addition to playing the role of important indicators of environmental contamination by oocysts of T. gondii. We studied the prevalence of infection by the protozoan in chickens of different breeding systems mesoregions from the states of Rio Grande do Norte and Paraiba: broilers from commercial farms (200/PB) and free-range chickens of small farms (322/RN and PB). Were standardized IFAT and ELISA techniques for detecting specific antibodies in blood samples of birds, and commercial kit was used to determine the prevalence by IHAT. There was no seropositive reaction by T. gondii in the samples of broilers tested, indicating that the particularities of intensive management limit the chances of infection for these animals. Among the hens, the frequency of IgG anti-T. gondii diagnosed by the techniques of IHAT, IFAT and ELISA, respectively, were 3.73% (12/322), 37.88% (122/322) and 40.37% (130/322), for both young and adult animals. Amongst the seropositive samples by IFAT, 33 (27.05%) were positive at a dilution of 1:16, in 1:32, 31 (25.41%), in 1:64, 24 (19.67%), 15 (12.29%) in 1:128, and 19 presented titer greater than or equal to 1:256 (15.57%). The evaluation of the presence of anti-T. gondii should be careful, and reagents IHAT provided erratic results in this measure for the specie studied. This suggests the need for own standardization of the kit before the use in epidemiological studies in animal species. On the other hand, substantial agreement observed between IFAT and ELISA techniques (Kappa = 0.62) enables these methods as effective methodologies for the diagnosis of toxoplasmosis in chickens. The high prevalence of specific antibodies among poultry in the region studied attempts to the potential risk of transmission of toxoplasmosis to humans / A toxoplasmose ? uma zoonose causada pelo Toxoplasma gondii, protozo?rio que tem distribui??o geogr?fica cosmopolita e pouca especificidade parasit?ria. Comumente de curso benigno e autolimitante, a infec??o pode manifestar-se de forma sist?mica grave, tornando-se grav?ssima em fetos e pacientes com imunodepress?o. Galinhas dom?sticas s?o consideradas um dos mais importantes hospedeiros na epidemiologia da toxoplasmose, uma vez que s?o potenciais fontes de infec??o para humanos, al?m de desempenharem o papel de importantes indicadores da contamina??o ambiental por oocistos de T. gondii. Neste trabalho, estudou-se a frequ?ncia da infec??o pelo protozo?rio em galin?ceos de diferentes sistemas de cria??o provenientes de mesorregi?es dos estados do Rio Grande do Norte e Para?ba, tanto frangos de corte de granjas comerciais (200/PB), como galinhas caipira de pequenas propriedades rurais (322/RN e PB). Foram padronizadas t?cnicas de RIFI e ELISA para a detec??o de anticorpos s?ricos espec?ficos nas amostras sangu?neas das aves, e foi utilizado kit comercial para determina??o dessa preval?ncia pelo HAI. N?o foi observada infec??o por T. gondii em nenhuma das amostras de frango de corte analisada, indicando que particularidades do manejo intensivo limitam as chances de infec??o para esses animais. Entre as galinhas caipira, a frequ?ncia de anticorpos IgG anti-T. gondii diagnosticada pelas t?cnicas de HAI, RIFI e ELISA foi, respectivamente, 3,73% (12/322), 37,88% (122/322) e 40,37% (130/322), analisando animais jovens e adultos. Das amostras soropositivas pela RIFI, 33 (27,05%) foram reagentes na dilui??o 1:16; em 1:32, 31 (25,41%); em 1:64, 24 (19,67%); 15 (12,29%) em 1:128 e 19 apresentaram titula??o maior ou igual a 1:256 (15,57%). A avalia??o da presen?a de anticorpos anti-T. gondii deve ser criteriosa, sendo que os reagentes do HAI forneceram resultados err?ticos nesta medida, para a esp?cie estudada, sugerindo a necessidade de padroniza??o pr?pria dos kits para diagn?stico antes do uso em estudos epidemiol?gicos em esp?cies animais. Por outro lado, a concord?ncia substancial observada entre as t?cnicas RIFI e ELISA (Kappa = 0,62) capacita estas metodologias como t?cnicas eficazes no diagn?stico da infec??o pelo protozo?rio em galin?ceos. A alta frequ?ncia de anticorpos espec?ficos observada entre as aves da regi?o estudada atenta para o risco potencial de transmiss?o da toxoplasmose para o homem
5

Avaliação do endotélio da córnea de galinhas (Gallus gallus domesticus) em diferentes faixas etárias utilizando a microscopia especular

Freitas, Luciana Vicente Rosa Pacicco de January 2012 (has links)
O endotélio corneano é uma monocamada de células poligonais localizadas na face posterior da córnea e é essencial para a manutenção da transparência corneana. Não foram encontradas referências na literatura a respeito dos parâmetros morfológicos e morfométricos do endotélio da córnea de galinhas, apesar destes animais serem amplamente utilizados como modelo experimental em estudos oftálmicos, devido à similitude com a córnea de humanos. O objetivo deste estudo foi o de avaliar os parâmetros morfométricos e o pleomorfismo da região central do endotélio da córnea de galinhas (Gallus gallus domesticus) de diferentes faixas etárias, utilizando a microscopia especular de contato. Avaliaram-se a densidade, a área celular média e o pleomorfismo das células do endotélio da córnea de 60 olhos de 30 galinhas da raça Leghorn branca. Os animais foram divididos em três grupos composto por 10 animais cada: G1 (animais com 30 dias de idade), G2 (animais com 45 dias de idade) e G3 (animais com 60 dias de idade). O presente estudo revelou que o endotélio da córnea de galinhas é composto por células poligonais de padrão regular, com predomínio de formato hexagonal. O endotélio corneano de galinhas sofreu alterações decorrentes da idade no que tange a morfometria, mas no que diz respeito ao pleomorfismo, não ocorreram alterações em resposta ao envelhecimento. / The corneal endothelium is a monolayer of polygonal cells located on the posterior face of the cornea and it is essential for the maintenance of corneal transparency. We found no references in the literature concerning the morphological and morphometric parameters of the corneal endothelium of chickens, although these animals are widely used as experimental model in ophthalmic studies due to the similarity with the human cornea. The objective of this study was to evaluate the morphometric parameters and the pleomorphism of central corneal endothelium of chickens (Gallus gallus domesticus) of different ages using the contact specular microscopy. The density, the average cell area and the pleomorphism of the corneal endothelial cells were evaluated on 60 eyes of 30 white Leghorn chickens. The animals were divided into three groups of 10 animals each: G1 (animals with 30 days of age), G2 (animals with 45 days of age) and G3 (animals with 60 days of age). The present study revealed that the corneal endothelium of chickens is composed of regular polygonal cells, with predominance of hexagonal shape. The corneal endothelium of chickens has changed due to age in respect to morphometry, but in regard to pleomorphism, no changes occurred in response to aging.
6

Avaliação do endotélio da córnea de galinhas (Gallus gallus domesticus) em diferentes faixas etárias utilizando a microscopia especular

Freitas, Luciana Vicente Rosa Pacicco de January 2012 (has links)
O endotélio corneano é uma monocamada de células poligonais localizadas na face posterior da córnea e é essencial para a manutenção da transparência corneana. Não foram encontradas referências na literatura a respeito dos parâmetros morfológicos e morfométricos do endotélio da córnea de galinhas, apesar destes animais serem amplamente utilizados como modelo experimental em estudos oftálmicos, devido à similitude com a córnea de humanos. O objetivo deste estudo foi o de avaliar os parâmetros morfométricos e o pleomorfismo da região central do endotélio da córnea de galinhas (Gallus gallus domesticus) de diferentes faixas etárias, utilizando a microscopia especular de contato. Avaliaram-se a densidade, a área celular média e o pleomorfismo das células do endotélio da córnea de 60 olhos de 30 galinhas da raça Leghorn branca. Os animais foram divididos em três grupos composto por 10 animais cada: G1 (animais com 30 dias de idade), G2 (animais com 45 dias de idade) e G3 (animais com 60 dias de idade). O presente estudo revelou que o endotélio da córnea de galinhas é composto por células poligonais de padrão regular, com predomínio de formato hexagonal. O endotélio corneano de galinhas sofreu alterações decorrentes da idade no que tange a morfometria, mas no que diz respeito ao pleomorfismo, não ocorreram alterações em resposta ao envelhecimento. / The corneal endothelium is a monolayer of polygonal cells located on the posterior face of the cornea and it is essential for the maintenance of corneal transparency. We found no references in the literature concerning the morphological and morphometric parameters of the corneal endothelium of chickens, although these animals are widely used as experimental model in ophthalmic studies due to the similarity with the human cornea. The objective of this study was to evaluate the morphometric parameters and the pleomorphism of central corneal endothelium of chickens (Gallus gallus domesticus) of different ages using the contact specular microscopy. The density, the average cell area and the pleomorphism of the corneal endothelial cells were evaluated on 60 eyes of 30 white Leghorn chickens. The animals were divided into three groups of 10 animals each: G1 (animals with 30 days of age), G2 (animals with 45 days of age) and G3 (animals with 60 days of age). The present study revealed that the corneal endothelium of chickens is composed of regular polygonal cells, with predominance of hexagonal shape. The corneal endothelium of chickens has changed due to age in respect to morphometry, but in regard to pleomorphism, no changes occurred in response to aging.
7

Frequência de anticorpos anti-Toxocara em frangos criados em sistema semi-intensivo, no Norte do Paraná, Sul do Brasil / Frequency of anti-Toxocara antibodies in broiler chickens reared under semi-intensive system, in the State of Paraná, southern Brazil

OLIVEIRA, Adilson Cardoso de 28 June 2017 (has links)
Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-02-07T17:46:54Z No. of bitstreams: 2 ADILSON OLIVEIRA.pdf: 313073 bytes, checksum: 760378e31125b9946d2bbf47c1aeafdb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-07T17:46:54Z (GMT). No. of bitstreams: 2 ADILSON OLIVEIRA.pdf: 313073 bytes, checksum: 760378e31125b9946d2bbf47c1aeafdb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-28 / Toxocariasis is an important zoonosis of worldwide distribution. The main way of transmission of the disease to human is the ingestion of soil containing embryonated eggs of Toxocara spp., the etiological agent. Studies have indicated the ingestion of raw or undercooked meat of chickens as another way of transmission. Besides, free-range chickens have been considered a good sentinel for the contamination of soil by Toxocara spp. eggs. The aim of this study was to evaluate the presence of anti-Toxocara antibodies in naturally infected broiler chickens (n=189) slaughtered in an abattoir located in Paraná, southern Brazil. The chickens were reared in a semi-intensive system by small familial farmers (n=7). An ELISA test was performed to detect the presence of anti-Toxocara IgY after serum adsorption with Ascaridia galli extract. An overall seroprevalence of 67.7% (128/189; 95% confidence interval [CI] = 61.1-74.4) was observed. The frequency of positive animals by farm ranged from 29.6% to 100%. The optical density and reactivity index indicated the possible chronicity of infection of the evaluated chickens. Associations between the presence of antibodies and the area where chickens were reared (p = 0.382) or the population density of dogs on the farm (p = 0.785) were not observed. This study shows a high frequency of Toxocara spp. infection in broiler chickens reared in semi-intensive systems and provides significant evidence that chickens are good indicator of environmental contamination by larva migrans agents. Further studies are necessary to assess the risk factors associated with poultry infection and the likelihood of toxocariasis transmission to humans via the ingestion of free-range chicken meat. / Toxocaríase é uma importante zoonose, com ampla distribuição mundial. A principal via de transmissão da doença para humanos se deve à ingestão acidental de ovos de Toxocara spp. presentes NO solo. Estudos têm descrito a infecção de seres humanos pelo consumo de carne crua ou mal cozida de frango. Os frangos criados em sistema semi-intensivo têm sido também considerados como sentinelas para a contaminação de solo por ovos de Toxocara spp. Com a finalidade de avaliar a presença de anticorpos anti-Toxocara em frangos de corte, foram colhidas 189 amostras de sangue de frangos em um abatedouro no Norte do Paraná. Os frangos foram criados em sistema colonial/caipira (sistema semi-intensivo), em pequenas propriedades rurais (n=7) pertencentes a produtores vinculados a uma associação de pequenos produtores. Os testes sorológicos foram realizados pela técnica de ELISA indireto, utilizando-se antígenos excretórios-secretórios (TES) de Toxocara canis para detecção de anticorpos IgY (IgG), com preadsorção do soro com antígenos de Ascaridia galli, para redução de reações cruzadas. Como resultado, foi obtida uma prevalência de 67,7% (128/189; IC 95%= 61,1-74,4), com uma variação de 29.6% a 100% entre as propriedades. Não foi observada correlação entre a positividade dos animais quando comparada a área (p= 0,382) e a densidade populacional de cães por propriedade (p= 0,785). Os resultados demonstraram alta frequência de anticorpos anti-Toxocara em frangos de corte criados em sistema semi-intensivo, indicando que essas aves podem ser indicadores de contaminação ambiental por agentes de larva migrans. Outros estudos são necessários para avaliar os riscos associados à transmissão de toxocaríase aos humanos pelo consumo da carne de frangos criados no sistema colonial/caipira.
8

Behavioural Economics: The Inferior-Good Effect

Messick, Eric Michael January 2007 (has links)
These experiments used 15 domestic hens to investigate the inferior-good effect, a decrease in consumption of a commodity as income increases. Experiment 1 investigated plain and salted wheat to serve as superior goods (opposite to inferior goods) and inferior goods. Hens consumed mostly plain wheat when given ad-libitum access so it was the intended superior good and salted wheat was the intended inferior good. In the next experiments, 3 s of plain wheat and 10 s of salted wheat were available for single responses on 2 keys during discrete trials. Income changed by changing the inter-trial interval (ITI) of fixed-length sessions or the total number of trials. Experiment 2 partially replicated the Silberberg et al. (1987) procedure, using the ITI income analogue for 6 hens. When income increased, 4 hens sometimes responded less on the salted-wheat key (demonstrating the inferior-good effect), 2 of these hens and a 5th hen sometimes responded more on both keys but proportionally more on the plain-wheat key (termed here as a relative inferior-good effect). Experiment 3a partially replicated the Hastjarjo et al. (1990a) procedure using the total-trials analogue for 7 other hens. The inferior-good effect occurred across some conditions for 2 hens while other hens tended to respond on the plain-wheat key, suggesting lack of contingency contact. When a 60-s ITI was added in Experiment 3b, variability increased for most hens, but only 1 hen showed the effect, 1 of the hens that did so in Experiment 3b. These 6 hens' (1 died) 80% bodyweights were re-assessed in Experiment 4 and hens were below 80% during Experiments 3a and 3b, suggesting that the lack of the inferior-good effect was not due to some hens being at high weights. The ITI analogue was used for these 6 hens in Experiment 5 and the effect occurred for 2 hens. Experiment 6 added forced-choice trials to the total-trials analogue (with 60-s ITI) to guarantee contingency contact. The inferior- and/or relative-inferior-good effect occurred for 3 hens. Across Experiments 2 through 6, body weights were usually heavier in high-income conditions and a within-session pattern of early-salted-late-plain responding occasionally occurred. Crop capacities of 5 Experiment-2 hens and a new hen (1 died) were assessed in Experiment 7 and there was no relation between this measure and inferior-or relative-inferior-good effects. Experiments 8 and 9 examined effects of pre- and post-feed in low-income conditions using the ITI analogue. When hens were pre-fed, responding for 5 of 7 hens resembled responding in high-income conditions of Experiment 2 with more plain-wheat responding and similar or less salted-wheat responding in some conditions (behaviour similar to the inferior- and relative-inferior-good effects, but without the income change). A similar pattern was found for 4 of 5 hens when hens were post-fed in Experiment 9, suggesting that food in the digestive tract may have played a role, and perhaps not the income manipulations themselves, where it (or other component of body weight) may have abolished quantity (i.e., the intended-inferior-good) as a reinforcer. Although these experiments occasionally demonstrated inferior- and relative-inferior-good effects, but less convincingly than published studies, the effects of income may have been non-specific. The usefulness of the inferior-good concept and other income-related economic concepts are thus challenged.
9

Distribución del hierro en gallinas (Shaver). Influencia del contenido en hierro de la dieta.

Sáiz Zabalza, María del Puy 01 April 1986 (has links)
Al observar la existencia de pocos trabajos realizados en gallinas ("Gallus domesticus") sobre el contenido y distribución de hierro, así como sobre el metabolismo y requerimientos de este metal, orientamos nuestro estudio hacia la observación de posibles variaciones de los siguientes elementos: 1º) Contenido y distribución del hierro en función de la edad, en función del sexo y en el momento de la puesta en los principales órganos y tejidos del animal: hígado, bazo, riñones, corazón; músculo esquelético; intestino delgado: duodeno, yeyuno e íleon; plumas; líquido de perfusión (sangre más CINa 0.9%); carcasa.2º) Contenido en hierro ferritínico en hígado y bazo en función de la edad, en función del sexo y en el momento de la puesta.3º) Balance metabólico en función de la edad, en función del sexo y en el momento de la puesta. 4º) Distribución del hierro y balance metabólico en función del contenido en hierro en las dietas a las 13 semanas: machos y hembras, a las 24 semanas (hembras en estado de puesta). 5º) Determinación del contenido en hierro ferritínico en hígado y bazo en función del contenido en hierro en las dietas, a las 13 semanas: machos y hembras, a las 24 semanas (hembras en estado de puesta). Las experiencias se llevaron a cabo con gallinas pertenecientes a la raza Shaver, genéticamente selecciona-da como ponedora, a las siguientes edades: 4, 8, 13 y 18 semanas, machos y hembras, y gallinas en puesta (24 semanas). Escogimos (en los apartados 4º y 5º) las dos edades citadas, ya que a las 13 semanas son animales aún no adultos sexualmente, y en el segundo caso, sabemos que la puesta modifica el metabolismo del hierro.El número de animales por cada edad y sexo fue de nueve.
10

How does hatchery stress affect the development of play behavior?

Lundén, Gabrielle January 2022 (has links)
Play is a behavior mainly observed in young individuals that can differ greatly between species in both function and appearance. Presence of play indicates positive experiences in animals, making play a useful assessment tool for animal welfare. Commercial hatcheries expose chicks to several stressors that can affect both behavior and welfare. Unfortunately, our understanding of play behavior in chickens is still limited as only a few studies have been conducted.Therefore, the aim of this study was to describe the ontogeny of various play behaviors in modern laying hens and to investigate how stress affects play behavior in chicks. A total of 80 chicks were used whereas 40 were hatched at a hatchery and 40 were hatched under controlled conditions. The chicks were tested in groups of four in enriched test arenas twice a week during five weeks. Each test lasted 30 minutes and novel objects were placed inside the arena after 10 and 20 minutes. Behaviors were noted while analyzing videos from the experiment using one–zero sampling and later divided into the categories of solitary, social, and total play. A linear mixed model with repeated measures was used to investigate how treatment, age, and the interaction treatment*age affect play behavior. Chicks played more during certain ages and all forms of play showed a similar change with age over both treatments. The amount of play did not differ significantly between treatments but there was a numerical (non-significant) tendency for hatchery chicks to play more, which may indicate compensatory play.

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