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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.
41

Inseminação artificial por laparoscopia em ovinos utilizando espermatozóides descongelados e capacitados in vitro. / Laparoscopic ovine artificil insemination using frozen/thawed in vitro capacitated spermatozoa

Steigleder, Luiz Felipe January 2007 (has links)
A técnica de inseminação artificial (IA) por laparoscopia em ovinos foi utilizada pela primeira vez em 1982, o que tornou viável a utilização econômica do sêmen congelado nesta espécie. Os experimentos foram realizados com o objetivo de determinar as taxas de prenhez de ovelhas inseminadas por laparoscopia, utilizando 50 x 106 espermatozóides descongelados e capacitados in vitro. No experimento 1, foi utilizado sêmen de um reprodutor e 67 ovelhas com estros sincronizados, divididas aleatoriamente entre os grupos: sêmen congelado (SC1) e sêmen congelado capacitado in vitro (SCC1). As ovelhas foram submetidas à IA, com 50x106 espermatozóides, 56 e 60 horas, respectivamente, após a retirada das esponjas impregnadas com progesterona. No grupo SCC1, a taxa de prenhez foi de 48,39% (15/31) significativamente superior a do grupo SC1 de 25% (9/36). No experimento 2, utilizou-se um reprodutor e 100 ovelhas com os estros sincronizados, distribuídas aleatoriamente entre três grupos: sêmen fresco (SF2), SC2 e SCC2. Nos grupos SF2 e SC2 as fêmeas foram inseminadas com 100x106 espermatozóides e 56 horas após a retirada da progesterona. No grupo das fêmeas inseminadas com espermatozóides capacitados in vitro, utilizou-se 50x106 espermatozóides e um intervalo de 60 horas após retirada da progesterona. As taxas de prenhez diagnosticadas nos diferentes grupos experimentais foram: SF2 60,9% (25/41), SC2 56,70% (17/30) e SCC2 44,90% (13/29), não existindo diferença estatística entre os grupos. Os experimentos realizados mostraram a viabilidade doemprego, na espécie ovina, da IA por laparoscopia utilizando 50x106 espermatozóides descongelados e capacitados in vitro. / The ovine artificial insemination (AI) by laparoscopy was described the first time in 1982, since this time frozen semen became a tool for use under field conditions. Today one research goal is to achieve high preganancies rates after AI using a reduced number of frozen/thawed spermatozoa per dosis. The experiments were carried out with the objective to determine the pregnancy rate of ewes inseminated by laparoscopy, using 50 x 106 thawed and in vitro capacited spermatozoa. In the experiment 1 was used semen of one fertily ram and 67 ewes with synchronized estrus. The females were randomly distributed among two experimental groups: inseminated with frozen semen (SC1) or frozen and in vitro capacitated semen (SCC1). The ewes were submitted to the AI with 50x106 spermatozoa, 56 (SC1) or 60 (SCC1) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. In the group SCC1 the pregnancy rate was 48,39% (15/31) significantly different from the 25% (9/36) observed in the group SC1. In the experiment 2 was used one fertily ram and 100 ewes with synchronized estrus, distributed randomly among three groups: inseminated with fresh semen (SF2), 100 x 106 spermatozoa, SC2, 100 x 106 frozen spermatozoa and SCC2, 50 x 106 frozen and in vitro capacited spermatozoa. The moment of the laparoscopic AI was the same as used in the experiment 1: 56 (SF2 and SC2) or 60 (SCC2) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. The observed pregnancy rates were similar among the experimental groups: SF2 60,9% (25/41), SC2 56,70% (17/30) and SCC2 44,90% (13/29). Our experiments showed the ability of frozen/thawed and in vitro capacitated ovine spermatozoa to in vivo fertilize and promote the development of pregancies. In conclusion, itis possible to use 50x106 frozen/thawed and in vitro capacited spermatozoa for ovine laparoscopic AI.
42

Inseminação artificial por laparoscopia em ovinos utilizando espermatozóides descongelados e capacitados in vitro. / Laparoscopic ovine artificil insemination using frozen/thawed in vitro capacitated spermatozoa

Steigleder, Luiz Felipe January 2007 (has links)
A técnica de inseminação artificial (IA) por laparoscopia em ovinos foi utilizada pela primeira vez em 1982, o que tornou viável a utilização econômica do sêmen congelado nesta espécie. Os experimentos foram realizados com o objetivo de determinar as taxas de prenhez de ovelhas inseminadas por laparoscopia, utilizando 50 x 106 espermatozóides descongelados e capacitados in vitro. No experimento 1, foi utilizado sêmen de um reprodutor e 67 ovelhas com estros sincronizados, divididas aleatoriamente entre os grupos: sêmen congelado (SC1) e sêmen congelado capacitado in vitro (SCC1). As ovelhas foram submetidas à IA, com 50x106 espermatozóides, 56 e 60 horas, respectivamente, após a retirada das esponjas impregnadas com progesterona. No grupo SCC1, a taxa de prenhez foi de 48,39% (15/31) significativamente superior a do grupo SC1 de 25% (9/36). No experimento 2, utilizou-se um reprodutor e 100 ovelhas com os estros sincronizados, distribuídas aleatoriamente entre três grupos: sêmen fresco (SF2), SC2 e SCC2. Nos grupos SF2 e SC2 as fêmeas foram inseminadas com 100x106 espermatozóides e 56 horas após a retirada da progesterona. No grupo das fêmeas inseminadas com espermatozóides capacitados in vitro, utilizou-se 50x106 espermatozóides e um intervalo de 60 horas após retirada da progesterona. As taxas de prenhez diagnosticadas nos diferentes grupos experimentais foram: SF2 60,9% (25/41), SC2 56,70% (17/30) e SCC2 44,90% (13/29), não existindo diferença estatística entre os grupos. Os experimentos realizados mostraram a viabilidade doemprego, na espécie ovina, da IA por laparoscopia utilizando 50x106 espermatozóides descongelados e capacitados in vitro. / The ovine artificial insemination (AI) by laparoscopy was described the first time in 1982, since this time frozen semen became a tool for use under field conditions. Today one research goal is to achieve high preganancies rates after AI using a reduced number of frozen/thawed spermatozoa per dosis. The experiments were carried out with the objective to determine the pregnancy rate of ewes inseminated by laparoscopy, using 50 x 106 thawed and in vitro capacited spermatozoa. In the experiment 1 was used semen of one fertily ram and 67 ewes with synchronized estrus. The females were randomly distributed among two experimental groups: inseminated with frozen semen (SC1) or frozen and in vitro capacitated semen (SCC1). The ewes were submitted to the AI with 50x106 spermatozoa, 56 (SC1) or 60 (SCC1) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. In the group SCC1 the pregnancy rate was 48,39% (15/31) significantly different from the 25% (9/36) observed in the group SC1. In the experiment 2 was used one fertily ram and 100 ewes with synchronized estrus, distributed randomly among three groups: inseminated with fresh semen (SF2), 100 x 106 spermatozoa, SC2, 100 x 106 frozen spermatozoa and SCC2, 50 x 106 frozen and in vitro capacited spermatozoa. The moment of the laparoscopic AI was the same as used in the experiment 1: 56 (SF2 and SC2) or 60 (SCC2) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. The observed pregnancy rates were similar among the experimental groups: SF2 60,9% (25/41), SC2 56,70% (17/30) and SCC2 44,90% (13/29). Our experiments showed the ability of frozen/thawed and in vitro capacitated ovine spermatozoa to in vivo fertilize and promote the development of pregancies. In conclusion, itis possible to use 50x106 frozen/thawed and in vitro capacited spermatozoa for ovine laparoscopic AI.
43

Inseminação artificial por laparoscopia em ovinos utilizando espermatozóides descongelados e capacitados in vitro. / Laparoscopic ovine artificil insemination using frozen/thawed in vitro capacitated spermatozoa

Steigleder, Luiz Felipe January 2007 (has links)
A técnica de inseminação artificial (IA) por laparoscopia em ovinos foi utilizada pela primeira vez em 1982, o que tornou viável a utilização econômica do sêmen congelado nesta espécie. Os experimentos foram realizados com o objetivo de determinar as taxas de prenhez de ovelhas inseminadas por laparoscopia, utilizando 50 x 106 espermatozóides descongelados e capacitados in vitro. No experimento 1, foi utilizado sêmen de um reprodutor e 67 ovelhas com estros sincronizados, divididas aleatoriamente entre os grupos: sêmen congelado (SC1) e sêmen congelado capacitado in vitro (SCC1). As ovelhas foram submetidas à IA, com 50x106 espermatozóides, 56 e 60 horas, respectivamente, após a retirada das esponjas impregnadas com progesterona. No grupo SCC1, a taxa de prenhez foi de 48,39% (15/31) significativamente superior a do grupo SC1 de 25% (9/36). No experimento 2, utilizou-se um reprodutor e 100 ovelhas com os estros sincronizados, distribuídas aleatoriamente entre três grupos: sêmen fresco (SF2), SC2 e SCC2. Nos grupos SF2 e SC2 as fêmeas foram inseminadas com 100x106 espermatozóides e 56 horas após a retirada da progesterona. No grupo das fêmeas inseminadas com espermatozóides capacitados in vitro, utilizou-se 50x106 espermatozóides e um intervalo de 60 horas após retirada da progesterona. As taxas de prenhez diagnosticadas nos diferentes grupos experimentais foram: SF2 60,9% (25/41), SC2 56,70% (17/30) e SCC2 44,90% (13/29), não existindo diferença estatística entre os grupos. Os experimentos realizados mostraram a viabilidade doemprego, na espécie ovina, da IA por laparoscopia utilizando 50x106 espermatozóides descongelados e capacitados in vitro. / The ovine artificial insemination (AI) by laparoscopy was described the first time in 1982, since this time frozen semen became a tool for use under field conditions. Today one research goal is to achieve high preganancies rates after AI using a reduced number of frozen/thawed spermatozoa per dosis. The experiments were carried out with the objective to determine the pregnancy rate of ewes inseminated by laparoscopy, using 50 x 106 thawed and in vitro capacited spermatozoa. In the experiment 1 was used semen of one fertily ram and 67 ewes with synchronized estrus. The females were randomly distributed among two experimental groups: inseminated with frozen semen (SC1) or frozen and in vitro capacitated semen (SCC1). The ewes were submitted to the AI with 50x106 spermatozoa, 56 (SC1) or 60 (SCC1) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. In the group SCC1 the pregnancy rate was 48,39% (15/31) significantly different from the 25% (9/36) observed in the group SC1. In the experiment 2 was used one fertily ram and 100 ewes with synchronized estrus, distributed randomly among three groups: inseminated with fresh semen (SF2), 100 x 106 spermatozoa, SC2, 100 x 106 frozen spermatozoa and SCC2, 50 x 106 frozen and in vitro capacited spermatozoa. The moment of the laparoscopic AI was the same as used in the experiment 1: 56 (SF2 and SC2) or 60 (SCC2) hours, respectively, after retreat of the intra vaginal device impregnated with progesterona. The observed pregnancy rates were similar among the experimental groups: SF2 60,9% (25/41), SC2 56,70% (17/30) and SCC2 44,90% (13/29). Our experiments showed the ability of frozen/thawed and in vitro capacitated ovine spermatozoa to in vivo fertilize and promote the development of pregancies. In conclusion, itis possible to use 50x106 frozen/thawed and in vitro capacited spermatozoa for ovine laparoscopic AI.
44

Avaliação da dimetilacetamida e do glicerol na criopreservação do sêmen de suínos através de testes de fertilização in vitro / Evaluation of dimethylacetamide and glycerol on cryopreservation of boar semen through in vitro fertilization tests

Rambo, Gissele 24 November 2008 (has links)
Made available in DSpace on 2014-08-20T14:37:58Z (GMT). No. of bitstreams: 1 dissertacao_gissele_rambo.pdf: 235931 bytes, checksum: a4e2ca4dc38eed3295f04e66a374e019 (MD5) Previous issue date: 2008-11-24 / The evaluation of the efficiency of semen cryopreservation is critical to make the use of frozen semen feasible in artificial insemination programs in swine. This study compared the efficiency of two non-penetrating cryoprotectants (dimetilacetamide-DMA or glycerol) on parameters of post-thawing semen quality and in vitro fertility with frozen swine semen. The sperm-rich fractions of 28 ejaculates from four boars were frozen with either DMA or glycerol. The efficiency of semen freezing was evaluated through parameters of post-thawing semen quality and in vitro penetration (IVP) of swine oocytes and embryo production. For samples frozen with DMA, sperm motility (38.1%) and membrane integrity (39.9%) were greater (P < 0.05) than those for glycerol (21.9% and 13.0%, respectively). Both the IVP rate and the number of spermatozoa per oocyte were greater (P < 0.05) for DMA (27.9% and 29.2, respectively) than for glycerol (13.6% and 20.7, respectively). The cleavage rate with DMA and glycerol samples (13.0% and 15.6%, respectively) were similar (P > 0.05). The embryo development rate did not differ (P < 0.05) for DMA (15.8%) and glycerol (22.0%). Therefore, when compared to glycerol, DMA was associated with improved post-thawing semen quality and in vitro fertility. / A avaliação da eficiência da criopreservação do sêmen é uma importante ferramenta para viabilizar o uso de sêmen congelado na inseminação artificial em suínos. Um experimento foi realizado a fim de identificar qual crioprotetor interno (dimetilacetamida-DMA ou glicerol) seria associado com melhores indicadores de qualidade seminal pós-descongelamento e fertilidade in vitro com sêmen suíno congelado. A fração espermática rica em espermatozóides de 28 ejaculados provenientes de quatro machos foi congelada com DMA ou glicerol. Para estimar o sucesso da criopreservação do sêmen foram utilizados parâmetros de qualidade seminal pós-descongelamento, teste de penetração in vitro (TPIV) de ovócitos suínos e produção in vitro de embriões. Para amostras congeladas com DMA, a motilidade (38,1%) e a integridade da membrana espermática (39,9%) foram superiores (P < 0,05) às observadas com glicerol (21,9% e 13,0%, respectivamente). A taxa de TPIV e o número de espermatozóides por ovócito também foram superiores (P < 0,05) para a DMA (27,9% e 29,2, respectivamente) do que para o glicerol (13,6% e 20,7, respectivamente). A taxa de clivagem alcançada com a DMA (13,0%) foi similar (P > 0,05) à obtida com glicerol (15,6%). A taxa de desenvolvimento embrionário não diferiu (P > 0,05) entre DMA e glicerol (15,8% e 22,0%, respectivamente). Portanto, considerando o conjunto de todos os testes, em comparação com o glicerol, a DMA foi associada com melhores indicadores de qualidade seminal e fertilidade in vitro.
45

Congelamento de sêmen suíno: estudo de crioprotetores intra e extracelulares, metodologias de congelamento e marcador molecular de congelabilidade / Freezing of boar semen: study of penetrating and nonpenetrating cryoprotectants, freezing methods and freezability molecular marker

Bianchi, Ivan 27 February 2007 (has links)
Made available in DSpace on 2014-08-20T13:32:49Z (GMT). No. of bitstreams: 1 tese_ivan_bianchi.pdf: 495717 bytes, checksum: 66978c47d9c193a45f85b5cad5be6c3f (MD5) Previous issue date: 2007-02-27 / Although boar semen is available in the frozen format since 1975, its use has been restricted to very specific situations for many reasons: it requires spermatozoa concentration per dose twice to three times higher than that for cooled semen; semen processing is labor intensive; and farrowing rate and litter size are reduced. Thus, most of the artificial inseminations in swine are performed at the day of semen collection or at most at the following day, using liquid semen conditioned between 15 and 18 ºC. The aims of this thesis were: to evaluate distinct extenders for cooling semen, methods for freezing, centrifugation temperatures, the use of amides as penetrating cryoprotectants and of low density lipoprotein as nonpenetrating cryoprotectants, and the presence of specific protein factors in seminal plasma in the results that could be associated with boar semen freezability. Five experiments have been executed: four with evaluations in vitro (motility and cell membrane integrity); and one with fertilization in vivo. The control treatment was the freezing with glycerol at 3% concentration. The semen processing method that provide more efficient results consisted of semen cooling during 120 min up to a centrifugation temperature of 15 °C. We also identified a 26 kDa factor in the seminal plasma that is associated with maintenance of the integrity of the sperm cell membrane post-thawing. Additionally, parameters of semen quality in vitro with the use of dimetilacetamide at 5% were better than those observed with the most used penetrating cryoprotectant (glycerol 3%) as control, although no difference between those cryoprotectants was observed in vivo. This study demonstrated the association of components in the seminal plasma with the sperm quality, and presenting an alternative protocol of semen freezing-thawed boar semen based in the use of dimetilacetamide at 5%. / Apesar do sêmen suíno congelado estar disponível comercialmente deste 1975, o seu uso tem ocorrido somente em ocasiões específicas, pois, em relação ao uso de sêmen refrigerado, requer duas a três vezes maior número de espermatozóides por dose, o processamento do sêmen é trabalhoso, o tamanho da leitegada é diminuído em um a três leitões por parto e a taxa de parição é menor. Dessa forma, a grande maioria das inseminações artificiais nessa espécie utiliza sêmen diluído e acondicionado no estado líquido entre 15 e 18 ºC. Os objetivos desta tese foram: avaliar diferentes diluidores de resfriamento, metodologias de congelamento, temperaturas de centrifugação, uso de crioprotetores intracelulares a base de amidas e extracelulares baseados em lipoproteína de baixa densidade, além do estudo de fatores protéicos presentes no plasma seminal nos resultados de avaliações in vitro e in vivo de sêmen suíno congelado-descongelado. Foram executados cinco experimentos com avaliações da qualidade do sêmen congeladodescongelado, quatro experimentos com avaliações in vitro (motilidade e integridade de membrana) e um experimento com fertilização in vivo. O tratamento utilizado como controle foi o congelamento com glicerol na concentração de 3%. A melhor curva de resfriamento após a coleta até 15 °C, foi atingida com o tempo de 120 min. Foi identificado um fator de 26 kDa no plasma seminal, cuja ausência proporcionou melhores resultados de integridade de membrana plasmática após o descongelamento. O uso do crioprotetor intracelular dimetilacetamida na concentração de 5%, proporcionou nas avaliações in vitro, resultados superiores ao tratamento controle (glicerol 3%), não diferindo na avaliação in vivo. O presente estudo demonstrou a relação de componentes do plasma seminal com a qualidade espermática, além de apresentar um novo protocolo de congelamentodescongelamento de sêmen suíno baseado no uso de dimetilacetamida 5%.
46

Evaluation expérimentale des effets de la sélection sur des caractères de reproduction et de robustesse dans une population de porcs Large White / Experimental evaluation of the effects of selection on reproductive and robustness traits in a Large White pig population

Silalahi, Parsaoran 28 February 2017 (has links)
Des progrès importants ont été obtenus dans les principales populations porcines pour les caractères inclus dans l'objectif de reproduction, à savoir la croissance, l'efficacité alimentaire, la composition de la carcasse et, dans les lignées maternelles, la prolificité des truies. Les animaux sélectionnés pour une forte efficacité productive peuvent être particulièrement sensibles à des problèmes comportementaux, physiologiques ou immunologiques, c'est-à-dire être moins robustes. Ces effets défavorables de la sélection sont souvent difficiles à mettre en évidence, car les caractères correspondants ne sont pas systématiquement enregistrés dans les programmes de sélection. L'utilisation d’un stock de sperme congelé est une méthode élégante pour estimer les évolutions génétiques pour un grand nombre de caractères (habituellement non enregistrés). Deux groupes expérimentaux (L77 et L98) ont été produits par l'insémination de truies LW, nées en 1997-1998, soit avec du sperme congelé stocké à partir des verrats LW de 1977, soit avec du sperme frais de verrats nés en 1998. Cette étude a montré que deux décennies de sélection ont permis des progrès importants pour les principaux caractères d'intérêt, mais ont également affecté de façon défavorable des caractères tels que la longévité, le risque de mortalité, la variabilité de caractères, qui suggèrent un effet défavorable de la sélection sur la robustesse des porcs. Nos résultats soulignent la nécessité d'intégrer des caractères liés à la robustesse dans l'objectif de sélection des populations porcines. Il est donc nécessaire de poursuivre les recherches afin de mieux caractériser les différentes composantes de la robustesse et leur impact sur l’efficience, le bien-être et la santé des porcs afin de pouvoir définir les objectifs de sélection les plus pertinents pour l’avenir. / Large improvements have been obtained in major pig populations for traits included in the breeding goal, i.e. growth, feed efficiency, carcass composition and, in maternal lines, sow prolificacy. Animals selected for high production efficiency may in particular be more sensitive to behavioral, physiological, or immunological problems, I.e., be less robust. These adverse effects of selection are often difficult to reveal, as corresponding traits are not routinely recorded in breeding programs. The use of stored frozen semen has been shown to be an elegant method to estimate genetic trends for a large number of (usually not recorded) traits. Two experimental groups (L77 and L98) were produced by inseminating French Large White (LW) sows born in 1997-1998 with either stored frozen semen from the above-mentioned 1977 LW boars or with fresh semen from LW boars born in 1998. This study has shown that 2 decades of selection have resulted in large gains for major traits of interest, but have also adversely affected traits such as longevity, risk of mortality, trait variability, which tend to indicate an unfavorable effect of selection on pig robustness. Our results stress the necessity to integrate robustness related traits in the breeding goal of pig populations. Thus, further research is needed to better characterize the different components of robustness and their impact on pig efficiency, welfare and health to be able to define the most relevant breeding objectives for the future.

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