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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

Social influences on the motivation of laying hens

Barber, Joseph C. E. January 2001 (has links)
No description available.
2

The effects of early stress on life-time strategies of behaviour and coping in chickens ( Gallus gallus )

Macdonald, Barry January 2011 (has links)
Stress is often an important consideration for animal welfare. A number of factors can contribute to stress in domestic animals, most notably thoseused in food production. We investigated the effects and heritability of stress in domestic chickens (Gallus gallus). Using a spatial learning paradigm, we tested an early social isolation-stressed group and their offspring against unstressed controls, to determine if this cognitive function was negatively affected by stress. In the parental generation, we found that across sessions control birds improved in performance, indicating a learning trend. Stressed birds showed no difference across sessions, indicating a lack of learning. No effects of the parental treatment were found in the offspring of stress and control birds. Social isolation stress was found to affect spatial memory learning, however, we did not find evidence that the parental stress influenced the spatial abilities of the next generation despite changes in other behaviours.
3

Ocorrência e caracterização molecular de cryptosporidium spp. em aves (Gallus domesticus) criadas em diferentes sistemas no estado de São Paulo / Occurrence and molecular characterization of Cryptosporidium spp. In chickens (Gallus domesticus) raised in different systems in the state of São Paulo.

Santana, Bruna Nicoleti 18 December 2017 (has links)
Submitted by BRUNA NICOLETI SANTANA null (brunanicoleti.ata@hotmail.com) on 2018-01-03T20:39:17Z No. of bitstreams: 1 Defesa Final (revisado) - Bruna 2017.docx: 1811276 bytes, checksum: b32071976cc79d8b95968a135760d1b6 (MD5) / Rejected by Ederson Vasconcelos Pereira null (edersonpereira@fmva.unesp.br), reason: Falta o certificado de Aprovação com a data da Defesa. Favor colocar o Certificado e fazer as alterações quanto à bolsa FAPESP. on 2018-01-08T13:19:20Z (GMT) / Submitted by BRUNA NICOLETI SANTANA null (brunanicoleti.ata@hotmail.com) on 2018-01-08T16:35:49Z No. of bitstreams: 1 Defesa Final (revisado) - Bruna 2017.docx: 2115998 bytes, checksum: d53869153af6d87bd313087bb51809fe (MD5) / Approved for entry into archive by Ederson Vasconcelos Pereira null (edersonpereira@fmva.unesp.br) on 2018-01-08T19:37:16Z (GMT) No. of bitstreams: 1 santana_bn_me_araca_int.pdf.docx: 2115998 bytes, checksum: d53869153af6d87bd313087bb51809fe (MD5) / Made available in DSpace on 2018-01-08T19:37:16Z (GMT). No. of bitstreams: 1 santana_bn_me_araca_int.pdf.docx: 2115998 bytes, checksum: d53869153af6d87bd313087bb51809fe (MD5) Previous issue date: 2017-12-18 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se determinar a ocorrência de Cryptosporidium spp. em amostras de fezes de galinha doméstica em criações extensivas, semiextensivas e intensivas, no Estado de São Paulo, e avaliar três protocolos da reação em cadeia pela polimerase (nested PCR) para diagnóstico de Cryptosporidium spp. A purificação e concentração dos oocistos presentes em amostras fecais provenientes de 190 aves foram realizadas por meio de centrífugo-flutuação em solução de Sheather. As amostras foram submetidas à extração do DNA genômico dos oocistos e submetidas à pesquisa de Cryptosporidium spp. utilizando três protocolos de nested PCR para amplificação de fragmento parcial do gene da subunidade 18S do rRNA (18S rRNA), seguida de sequenciamento dos fragmentos amplificados. Os resultados obtidos pelos três protocolos de nested PCR foram analisados pelo teste de McNemar e pelo índice de correlação Kappa. As amostras que foram identificadas como Cryptosporidium meleagridis ou Cryptosporidium sp., pela análise do gene 18S rRNA, foram submetidas à caracterização adicional por meio de subgenotipagem de C. meleagridis pela nested PCR e sequenciamento de fragmento parcial do gene GP60 ou pela nested PCR e sequenciamento de fragmento parcial do gene da actina, respectivamente. A positividade total para Cryptosporidium (total de amostras positivas em pelo menos um método diagnóstico) obtida pela nested PCR foi de 12,6% (24/190), com identificação de Cryptosporidium baileyi (9,47%; 18/190), C. meleagridis (0,53%; 1/190), Cryptosporidium parvum (2,1%; 4/190) e Cryptosporidium sp. (0,53%; 1/190). A subgenotipagem de C. meleagridis revelou a presença do subtipo zoonótico IIIgA23G3R1. A análise do gene da actina permitiu a identificação de um novo genótipo de Cryptosporidium, em uma ave de criação extensiva, relacionado geneticamente com Cryptosporidium bovis e Cryptosporidium xiaoi. A análise de regressão logística não revelou diferenças significativas nas taxas de detecção de Cryptosporidium associadas aos diferentes sistemas de produção (extensivo, semi-intensivo e intensivo). Em comparação com frangos de corte, houve maior probabilidade de que as aves de postura e as aves de criações mistas fossem positivas para Cryptosporidium. Não houve diferença significativa na frequência de resultados positivos obtidos pelos três protocolos de nested PCR (p> 0,05); a concordância obtida pelo índice Kappa variou de substancial (0,70) a quase perfeita (0,9). / The objective of this study was to determine the occurrence of Cryptosporidium spp. in domestic chickens raised in different chicken production systems in Brazil using three nested PCR protocols. The purification and concentration of oocysts present in 190 fecal samples from chickens raised in extensive, semi-intensive and intensive production systems were accomplished by centrifugal flotation in Sheather's solution and were followed by the extraction of genomic DNA. The detection and molecular characterization of Cryptosporidium species and genotypes were performed using three nested polymerase chain reaction (nested PCR) protocols targeting the 18S rRNA gene followed by sequencing of the amplified fragments. The results obtained by the three nested PCR reactions were analyzed using the McNemar test and the Kappa correlation index. Subgenotyping of Cryptosporidium meleagridis was performed using a nested PCR reaction targeting the gp60 gene. Samples identified as Cryptosporidium sp. genetically similar to Cryptosporidium xiaoi and Cryptosporidium bovis by 18S rRNA gene sequencing were further analyzed by nested PCR targeting the actin gene and subsequent sequencing of the amplified fragment. The overall positivity for Cryptosporidium spp. (total samples positive in at least one protocol) from the nested PCR results was 12.6% (24/190), including Cryptosporidium baileyi (9.47%; 18/190), C. meleagridis (0.53%, 1/190), Cryptosporidium parvum (2.1%; 4/190) and Cryptosporidium sp. (0.53%; 1/190). Subgenotyping of C. meleagridis revealed the presence of the zoonotic subtype IIIgA23G3R1. Sequencing of the 18S rRNA gene and the actin gene fragments revealed a new Cryptosporidium genotype in an extensive poultry system genetically related to C. xiaoi and C. bovis. Logistic regression analysis did not reveal significant differences in the rates of Cryptosporidium detection associated with the variable production system (extensive, semi-intensive and intensive). In comparison to broiler chickens, there were higher odds for layer chickens and mixed chickens to be positive for Cryptosporidium. There was no significant difference in the frequency of positive results obtained by the three nested PCR protocols (p> 0.05); additionally, the agreement obtained by Kappa index ranged from substantial (0.70) to almost perfect (0.9). / FAPESP: 15/26334-8.
4

Ocorrência e caracterização molecular de cryptosporidium spp. em aves (Gallus domesticus) criadas em diferentes sistemas no estado de São Paulo /

Santana, Bruna Nicoleti January 2017 (has links)
Orientador: Marcelo Vasconcelos Meireles / Coorientador: Alex Akira Nakamura / Banca: Gisele Fabrino MAchado / Banca Weslen Fabricio Pires Teixeira / Resumo: Objetivou-se determinar a ocorrência de Cryptosporidium spp. em amostras de fezes de galinha doméstica em criações extensivas, semiextensivas e intensivas, no Estado de São Paulo, e avaliar três protocolos da reação em cadeia pela polimerase (nested PCR) para diagnóstico de Cryptosporidium spp. A purificação e concentração dos oocistos presentes em amostras fecais provenientes de 190 aves foram realizadas por meio de centrífugo-flutuação em solução de Sheather. As amostras foram submetidas à extração do DNA genômico dos oocistos e submetidas à pesquisa de Cryptosporidium spp. utilizando três protocolos de nested PCR para amplificação de fragmento parcial do gene da subunidade 18S do rRNA (18S rRNA), seguida de sequenciamento dos fragmentos amplificados. Os resultados obtidos pelos três protocolos de nested PCR foram analisados pelo teste de McNemar e pelo índice de correlação Kappa. As amostras que foram identificadas como Cryptosporidium meleagridis ou Cryptosporidium sp., pela análise do gene 18S rRNA, foram submetidas à caracterização adicional por meio de subgenotipagem de C. meleagridis pela nested PCR e sequenciamento de fragmento parcial do gene GP60 ou pela nested PCR e sequenciamento de fragmento parcial do gene da actina, respectivamente. A positividade total para Cryptosporidium (total de amostras positivas em pelo menos um método diagnóstico) obtida pela nested PCR foi de 12,6% (24/190), com identificação de Cryptosporidium baileyi (9,47%; 18/190), C. meleagridis ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to determine the occurrence of Cryptosporidium spp. in domestic chickens raised in different chicken production systems in Brazil using three nested PCR protocols. The purification and concentration of oocysts present in 190 fecal samples from chickens raised in extensive, semi-intensive and intensive production systems were accomplished by centrifugal flotation in Sheather's solution and were followed by the extraction of genomic DNA. The detection and molecular characterization of Cryptosporidium species and genotypes were performed using three nested polymerase chain reaction (nested PCR) protocols targeting the 18S rRNA gene followed by sequencing of the amplified fragments. The results obtained by the three nested PCR reactions were analyzed using the McNemar test and the Kappa correlation index. Subgenotyping of Cryptosporidium meleagridis was performed using a nested PCR reaction targeting the gp60 gene. Samples identified as Cryptosporidium sp. genetically similar to Cryptosporidium xiaoi and Cryptosporidium bovis by 18S rRNA gene sequencing were further analyzed by nested PCR targeting the actin gene and subsequent sequencing of the amplified fragment. The overall positivity for Cryptosporidium spp. (total samples positive in at least one protocol) from the nested PCR results was 12.6% (24/190), including Cryptosporidium baileyi (9.47%; 18/190), C. meleagridis (0.53%, 1/190), Cryptosporidium parvum (2.1%; 4/190) and Cryptosporidium sp.... (Complete abstract click electronic access below) / Mestre
5

Metabolomic study of the effects of perfluorinated compounds on the fatty acid metabolism during the development of Gallus gallus domesticus

Wigh, Viktoria January 2017 (has links)
Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are two commonly found contaminants associated with various manufacturing products, such as firefighting foam, non-stick coatings, electronics and water repellants. These compounds are persistent, bioaccumulative, and toxic and may therefore pose a serious health risk to living organisms. Earlier studies have shown that PFOS and PFOA affected the fatty acid β-oxidation, i.e. the energy metabolism in liver. This study evaluates the effects of PFOS and PFOA on fatty acid metabolism in domestic chicken liver cells.  Liver tissues were obtained from chicken embryos treated in ovo with PFOS or with PFOA at low (0.1 µg/g) and high (1.0 and 1.6 µg/g) concentration levels. The fatty acids were extracted and derivatized into fatty acid methyl esters (FAMEs). The analysis was conducted by gas chromatography coupled with mass spectrometry. Results showed that a lower concentration of PFOS and a lower percentage of DMSO significantly affected the concentrations of fatty acids in livers of chicken embryos. PFOA-treated samples also showed some significant elevated fatty acid concentrations. Almost all fatty acid concentrations of treated liver samples exceeded the concentrations of the untreated samples.

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