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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

Efeito do período de armazenagem, da temperatura de incubação e da forma física da ração sobre o desenvolvimento embrionário, a eclosão e as características dos ovos de perdizes Rhynchotus rufescens

Nakage, Eliana Saiuri [UNESP] 21 January 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-01-21Bitstream added on 2014-06-13T20:18:05Z : No. of bitstreams: 1 nakage_es_me_jabo.pdf: 306114 bytes, checksum: 6eec34287e9a48d064b56b155cad12bc (MD5) / O objetivo do presente estudo foi avaliar se a forma física da ração (farelada e peletizada) afeta a porosidade e espessura da casca, e porcentagem de perda de água e eclodibilidade dos ovos férteis de ovos de perdiz. Os ovos foram coletados logo após a postura e separados em diferentes intervalos de peso (35-45, 46-50, 51-55, 56-60 e 61-70g), sendo 10 ovos/classe/ração. O número de poros das cascas foi avaliado nas regiões apical, equatorial e basal dos ovos. Utilizou-se um micrômetro digital para a mensuração da espessura das três regiões da casca dos ovos, a partir dos quais obteve-se a espessura média por ovo. Os ovos para avaliação da eclodibilidade dos ovos férteis e porcentagem de perda de água do ovo foram pesados, desinfectados, incubados (T=35,5o C e UR= 60%) e transferidos no 16º dia de incubação para o nascedouro, onde foram mantidos até a eclosão. Os dados mostraram que, em perdizes, o número de poros na casca pode variar com a região da casca, peso do ovo e a forma física da ração, e que a ingestão de ração peletizada promove um aumento na espessura da casca dos ovos sem alterar a eclodibilidade dos ovos férteis e a porcentagem de perda de água dos mesmos durante a incubação. / The aim of this study was to determine the effect of the ingestion of meal and pelleted diets on eggshell porosity and thickness, water loss and hatchability percentages of partridge (Rhynchotus rufescens) eggs. The eggs (n=100) were divided into five different weight classes (1: 35-45 g, 2: 46-50 g, 3: 51-55 g, 4: 56-60 g, 5: 61-70 g). Parts from different regions (air space, equator and small end) of each eggshell were analized in order to count pore numbers. Eggshell thickness measurements were carried out after removal of the egg membranes. The eggs used in the analyses of the water loss and hatchability percentages were weighed, desinfected, and then incubated (T=35.5oC and RH=60%). On the 16th day of incubation, these eggs were transferred to a hatchery maintained at temperature and RH similar to those used in the incubator, where they were kept until hatching. The results showed that the mean number of eggshell pores changed among the three regions of the eggshell and egg weight classes, and also between the physical form of diets. Ingestion of pelleted diet increased eggshell thickness; however, hatchability and water loss percentages remained unchanged.
2

Impact of Parthenogenetic Development on Egg Albumen Characteristics and Subsequent Fertilization Success in Chinese Painted Quail

Santa Rosa, Priscila 15 August 2014 (has links)
Parthenogenetic development (PD) in Chinese Painted quail decreases hatchability and increases early embryonic mortality. The objectives of this study were to determine if PD alters egg albumen ions, gases, and pH (virgin and mated hens) as well as the success of subsequent fertilization in mated quail and if egg storage and incubation temperature increase PD. In virgin hens, PD altered albumen characteristics over incubation. In fact, albumen from mated and virgin hens exhibiting PD showed similar albumen characteristics, and these characteristics were similar to early dead embryos in mated hens. Also, mated hens selected for parthenogenesis had less sperm holes in the perivitelline membrane and a higher percentage of eggs without holes as compared to birds not selected for parthenogenesis. Increasing storage and incubational temperature increased PD and parthenogen size. In conclusion, PD alters egg albumen characteristics, decreases fertility, and can be affected by storage and incubation temperatures.
3

A remoção do folículo dominante como estratégia anti-luteolítica em bovinos / The removal of the dominant follicle as antiluteolytic strategy in cattle

Machado, Rui 22 August 2005 (has links)
O estradiol secretado pelo folículo dominante (DOM) desempenha importante papel na luteólise da vaca. Em adição, o reconhecimento materno da prenhez (MRP) requer um ambiente uterino otimizado, o qual por sua vez depende da função luteínica e de adequadas concentrações de progesterona circulante. Os objetivos do presente estudo foi testar diferentes estratégias para otimizar a função luteínica e prevenir a influência de um DOM durante o período crítico (CP) para o MRP (de D13 a D20 após o estro o estro). Diferentes abordagens foram testadas. No exp.1, 23 vacas Nelore foram tratadas com o protocolo ovsynch para induzir um cio sincronizado (D0). As vacas receberam: Gc (n=7) - nada mais; ThCG (n=5) - 3000 IU de hCG no D5; TE2 (n=6) - 5mg de 17b-estradiol (E2) no D12; ThCG/E2 (n=5) - hCG/D5 + E2/D12. Ultra-sonografias e dosagens de progesterona plasmática durante o ciclo estral permitiram determinar que o E2 reprogramou o ciclo ovariano ao prevenir a presença (P⁢0,05) de um DOM durante quase todo CP (0,6±0,7 dias entre D15 e D20), porém o E2 induziu a luteólise. As vacas que receberam a hCG desenvolveram corpo lúteo acessório e tiveram [P4] mais alta até o D13 (P⁢0,05). Portanto, a fase luteínica não foi prolongada No exp.2, os mesmos tratamentos foram impostos a 220 vacas Nelore (55 por grupo) após uma inseminação artificial em tempo fixo (TAI). As taxas de prenhez (PR) à TAI ou às inseminais de repasse durante uma estação com 64 dias de duração foram diminuídas (P⁢0,05) quando o E2 foi usado e a hCG não foi capaz de aumentar aquelas PR. No exp.3, vacas Red Angus no pós-parto tiveram seu estro sincronizado (D0) e receberam: nada mais (GCT, n=5) ou 200mg de gonadorrelina no D5 mais 3000 IU hCG no D13 (GRF, n=5); ou ablação de todos folículos ³7mm através de aspiração folicular em D14, D17 e D20 (GRM, n=5). GRF teve luteólise retardada (18,2±1,0b dias, 23,6&plusmn1,0a dias e 18,7&plusmn1,2b dias para GCT, GRF e GRM, respectivamente) e maior [P4] que os outros grupos. Folículos maiores que 7mm foram observados quando das aspirações. Foi possível concluir que: a) E2 permitiu consistentemente reprogramar o desenvolvimento folicular, porém causou luteólise e o seu uso trouxe efeitos negativos sobre as PR; b) a hCG melhorou a função luteínica mas não aumentou as PR; c) a ablação dos folículos ³7mm não preveniu a presença do DOM no CP para o MRP e d) a associação GnRH/hCG otimizou a função luteínica, retardou a luteólise e prolongou a fase luteínica de modo que todo o CP esteve sob influência da progesterona / Estradiol secreted from the dominant follicle (DOM) plays a key role in triggering luteolysis in the cow. In addition, maternal recognition of pregnancy (MRP) requires an optimum uterine environment, which directly depends on luteal function and adequate levels of circulating progesterone. The aim of this study was to test different strategies to optimize luteal function and prevent the influence of a DOM throughout the critical period (CP) for MRP (from D13 to D20 after estrus). Different approaches were tested. In exp.1, 23 Nelore cows were treated with the ovsync protocol to induce a synchronized estrus (D0). Cows received: Gc (n=7) - nothing else; ThCG (n=5) - 3000 IU of hCG five days (D5) after estrus; TE2 (n=6) - 5mg of 17b-estradiol (E2) on D12; ThCG/E2 (n=5) - hCG/D5 + E2/D12. Ultrasound evaluation and plasmatic progesterone concentration ([P4]) throughout estrous cycle allowed to conclude: E2 reprogrammed ovarian cycle by preventing the presence (P⁢.05) of a DOM during almost all CP (0.6±.7 days within the D15 to D20 interval) but induced luteolysis; cows receiving hCG developed accessory corpus luteum and had higher [P4] up to D13 (P⁢.05). Therefore, luteolysis was not delayed and luteal phase was not prolonged. In exp.2, same treatments were imposed to 220 Nelore cows (55 per group) after a timed artificial insemination (TAI). Pregnancy rates (PR) at TAI or at AIs thereafter over a 64-day period were reduced (P⁢0.05) by using E2 and hCG was not capable to improve those PR. In exp.3, postpartum Red Angus cows were estrus synchronized (D0) and received: nothing else (GCT, n=5) or 200mg of gonadorrelin on D5 plus 3000 IU hCG on D13 (GRF, n=5); or ablation of all follicles ³7mm through follicular aspiration on D14, D17 and D20 (GRM, n=5). GRF had delayed luteolysis (18.2±1.0b days, 23.6±1.0a days, 18.7±1.2b days for GCT, GRF, GRM, respectively) and higher [P4] than other groups. Follicles larger than 7mm were observed in all occasions of aspiration. In could be concluded that: a) E2 allowed to consistently reschedule follicular development but caused luteolysis and its use was detrimental to PR; b) hCG improved luteal function but did not increase PR; c) ablation of 7mm follicles did not prevent a DOM throughout CP for MRP and d) GnRH/hCG association optimized luteal function, delayed luteolysis and prolonged luteal phase in such a way that all CP was under progesterone influence
4

A remoção do folículo dominante como estratégia anti-luteolítica em bovinos / The removal of the dominant follicle as antiluteolytic strategy in cattle

Rui Machado 22 August 2005 (has links)
O estradiol secretado pelo folículo dominante (DOM) desempenha importante papel na luteólise da vaca. Em adição, o reconhecimento materno da prenhez (MRP) requer um ambiente uterino otimizado, o qual por sua vez depende da função luteínica e de adequadas concentrações de progesterona circulante. Os objetivos do presente estudo foi testar diferentes estratégias para otimizar a função luteínica e prevenir a influência de um DOM durante o período crítico (CP) para o MRP (de D13 a D20 após o estro o estro). Diferentes abordagens foram testadas. No exp.1, 23 vacas Nelore foram tratadas com o protocolo ovsynch para induzir um cio sincronizado (D0). As vacas receberam: Gc (n=7) - nada mais; ThCG (n=5) - 3000 IU de hCG no D5; TE2 (n=6) - 5mg de 17b-estradiol (E2) no D12; ThCG/E2 (n=5) - hCG/D5 + E2/D12. Ultra-sonografias e dosagens de progesterona plasmática durante o ciclo estral permitiram determinar que o E2 reprogramou o ciclo ovariano ao prevenir a presença (P⁢0,05) de um DOM durante quase todo CP (0,6±0,7 dias entre D15 e D20), porém o E2 induziu a luteólise. As vacas que receberam a hCG desenvolveram corpo lúteo acessório e tiveram [P4] mais alta até o D13 (P⁢0,05). Portanto, a fase luteínica não foi prolongada No exp.2, os mesmos tratamentos foram impostos a 220 vacas Nelore (55 por grupo) após uma inseminação artificial em tempo fixo (TAI). As taxas de prenhez (PR) à TAI ou às inseminais de repasse durante uma estação com 64 dias de duração foram diminuídas (P⁢0,05) quando o E2 foi usado e a hCG não foi capaz de aumentar aquelas PR. No exp.3, vacas Red Angus no pós-parto tiveram seu estro sincronizado (D0) e receberam: nada mais (GCT, n=5) ou 200mg de gonadorrelina no D5 mais 3000 IU hCG no D13 (GRF, n=5); ou ablação de todos folículos ³7mm através de aspiração folicular em D14, D17 e D20 (GRM, n=5). GRF teve luteólise retardada (18,2±1,0b dias, 23,6&plusmn1,0a dias e 18,7&plusmn1,2b dias para GCT, GRF e GRM, respectivamente) e maior [P4] que os outros grupos. Folículos maiores que 7mm foram observados quando das aspirações. Foi possível concluir que: a) E2 permitiu consistentemente reprogramar o desenvolvimento folicular, porém causou luteólise e o seu uso trouxe efeitos negativos sobre as PR; b) a hCG melhorou a função luteínica mas não aumentou as PR; c) a ablação dos folículos ³7mm não preveniu a presença do DOM no CP para o MRP e d) a associação GnRH/hCG otimizou a função luteínica, retardou a luteólise e prolongou a fase luteínica de modo que todo o CP esteve sob influência da progesterona / Estradiol secreted from the dominant follicle (DOM) plays a key role in triggering luteolysis in the cow. In addition, maternal recognition of pregnancy (MRP) requires an optimum uterine environment, which directly depends on luteal function and adequate levels of circulating progesterone. The aim of this study was to test different strategies to optimize luteal function and prevent the influence of a DOM throughout the critical period (CP) for MRP (from D13 to D20 after estrus). Different approaches were tested. In exp.1, 23 Nelore cows were treated with the ovsync protocol to induce a synchronized estrus (D0). Cows received: Gc (n=7) - nothing else; ThCG (n=5) - 3000 IU of hCG five days (D5) after estrus; TE2 (n=6) - 5mg of 17b-estradiol (E2) on D12; ThCG/E2 (n=5) - hCG/D5 + E2/D12. Ultrasound evaluation and plasmatic progesterone concentration ([P4]) throughout estrous cycle allowed to conclude: E2 reprogrammed ovarian cycle by preventing the presence (P⁢.05) of a DOM during almost all CP (0.6±.7 days within the D15 to D20 interval) but induced luteolysis; cows receiving hCG developed accessory corpus luteum and had higher [P4] up to D13 (P⁢.05). Therefore, luteolysis was not delayed and luteal phase was not prolonged. In exp.2, same treatments were imposed to 220 Nelore cows (55 per group) after a timed artificial insemination (TAI). Pregnancy rates (PR) at TAI or at AIs thereafter over a 64-day period were reduced (P⁢0.05) by using E2 and hCG was not capable to improve those PR. In exp.3, postpartum Red Angus cows were estrus synchronized (D0) and received: nothing else (GCT, n=5) or 200mg of gonadorrelin on D5 plus 3000 IU hCG on D13 (GRF, n=5); or ablation of all follicles ³7mm through follicular aspiration on D14, D17 and D20 (GRM, n=5). GRF had delayed luteolysis (18.2±1.0b days, 23.6±1.0a days, 18.7±1.2b days for GCT, GRF, GRM, respectively) and higher [P4] than other groups. Follicles larger than 7mm were observed in all occasions of aspiration. In could be concluded that: a) E2 allowed to consistently reschedule follicular development but caused luteolysis and its use was detrimental to PR; b) hCG improved luteal function but did not increase PR; c) ablation of 7mm follicles did not prevent a DOM throughout CP for MRP and d) GnRH/hCG association optimized luteal function, delayed luteolysis and prolonged luteal phase in such a way that all CP was under progesterone influence
5

Embryonic Mortality and Sex Ratios in the Tree Sparrow

Svensson, Magnus January 2006 (has links)
<p>Tree sparrows (Passer montanus) have been studied in two areas in Sweden since 1997. At both sites, tree sparrow eggs had remarkably low hatching success. On average only 60% of the eggs hatched. Analyses have shown that this was caused by embryonic mortality, which was highly sex biased. About 70 % of the dead embryos were males, while about 65 % of all fledged nestlings were females. Impaired hatching success here related to two factors. Hatching success was lower for pairs with a male in poor body condition, and it was lower in areas with a high local population density. </p><p>A sex bias in the mortality early in life has been demonstrated in several species. Since the competitive ability of males is determined by conditions early in life, parents with poor provisioning capacity should prefer to produce female offspring in broods reared under poor conditions. The body condition of a tree sparrow during the nestling stage was well correlated to the condition as an adult, and pairs in which the male parent was in poor condition produced chicks in poor condition. Since the breeding success of a pair depended more on the condition of the male, females appear less affected by conditions early in life. Parents with poor provisioning capacity appear to bias offspring survival towards females, and a difference in the early susceptibility may be adaptive. </p><p>Changes in birth sex ratios have in some cases been suspected to result from exposure to estrogenic environmental pollutants. This was examined by exposing great- and blue tit embryos to a synthetic estrogen. Although there was a difference in the mortality rate, the difference was present also in the control groups, why this could not be attributed to estrogen exposure.</p>
6

Embryonic Mortality and Sex Ratios in the Tree Sparrow

Svensson, Magnus January 2006 (has links)
Tree sparrows (Passer montanus) have been studied in two areas in Sweden since 1997. At both sites, tree sparrow eggs had remarkably low hatching success. On average only 60% of the eggs hatched. Analyses have shown that this was caused by embryonic mortality, which was highly sex biased. About 70 % of the dead embryos were males, while about 65 % of all fledged nestlings were females. Impaired hatching success here related to two factors. Hatching success was lower for pairs with a male in poor body condition, and it was lower in areas with a high local population density. A sex bias in the mortality early in life has been demonstrated in several species. Since the competitive ability of males is determined by conditions early in life, parents with poor provisioning capacity should prefer to produce female offspring in broods reared under poor conditions. The body condition of a tree sparrow during the nestling stage was well correlated to the condition as an adult, and pairs in which the male parent was in poor condition produced chicks in poor condition. Since the breeding success of a pair depended more on the condition of the male, females appear less affected by conditions early in life. Parents with poor provisioning capacity appear to bias offspring survival towards females, and a difference in the early susceptibility may be adaptive. Changes in birth sex ratios have in some cases been suspected to result from exposure to estrogenic environmental pollutants. This was examined by exposing great- and blue tit embryos to a synthetic estrogen. Although there was a difference in the mortality rate, the difference was present also in the control groups, why this could not be attributed to estrogen exposure.
7

Efeito do período de armazenagem, da temperatura de incubação e da forma física da ração sobre o desenvolvimento embrionário, a eclosão e as características dos ovos de perdizes Rhynchotus rufescens /

Nakage, Eliana Saiuri. January 2003 (has links)
Orientadora: Isabel Cristina Boleli / Banca: Vera Maria Barbosa de Moraes / Banca: Maria Estela Gaglianone Moro / Resumo: O objetivo do presente estudo foi avaliar se a forma física da ração (farelada e peletizada) afeta a porosidade e espessura da casca, e porcentagem de perda de água e eclodibilidade dos ovos férteis de ovos de perdiz. Os ovos foram coletados logo após a postura e separados em diferentes intervalos de peso (35-45, 46-50, 51-55, 56-60 e 61-70g), sendo 10 ovos/classe/ração. O número de poros das cascas foi avaliado nas regiões apical, equatorial e basal dos ovos. Utilizou-se um micrômetro digital para a mensuração da espessura das três regiões da casca dos ovos, a partir dos quais obteve-se a espessura média por ovo. Os ovos para avaliação da eclodibilidade dos ovos férteis e porcentagem de perda de água do ovo foram pesados, desinfectados, incubados (T=35,5o C e UR= 60%) e transferidos no 16º dia de incubação para o nascedouro, onde foram mantidos até a eclosão. Os dados mostraram que, em perdizes, o número de poros na casca pode variar com a região da casca, peso do ovo e a forma física da ração, e que a ingestão de ração peletizada promove um aumento na espessura da casca dos ovos sem alterar a eclodibilidade dos ovos férteis e a porcentagem de perda de água dos mesmos durante a incubação. / Abstract: The aim of this study was to determine the effect of the ingestion of meal and pelleted diets on eggshell porosity and thickness, water loss and hatchability percentages of partridge (Rhynchotus rufescens) eggs. The eggs (n=100) were divided into five different weight classes (1: 35-45 g, 2: 46-50 g, 3: 51-55 g, 4: 56-60 g, 5: 61-70 g). Parts from different regions (air space, equator and small end) of each eggshell were analized in order to count pore numbers. Eggshell thickness measurements were carried out after removal of the egg membranes. The eggs used in the analyses of the water loss and hatchability percentages were weighed, desinfected, and then incubated (T=35.5oC and RH=60%). On the 16th day of incubation, these eggs were transferred to a hatchery maintained at temperature and RH similar to those used in the incubator, where they were kept until hatching. The results showed that the mean number of eggshell pores changed among the three regions of the eggshell and egg weight classes, and also between the physical form of diets. Ingestion of pelleted diet increased eggshell thickness; however, hatchability and water loss percentages remained unchanged. / Mestre
8

Impact of the age on early embryonic mortality (EEM) and embryo quality in the honey bee (Apis mellifera L.)

Al-Lawati, Hassan 09 December 2009 (has links)
Die vorliegende Studie über den Alterseinfluß bei der Honigbiene (Apis mellifera) besteht aus drei Hauptteilen. Der erste Teil befasst sich mit den Charakteristiken des Spermathekeninhalts alter und junger Bienenköniginnen. Im zweiten Teil geht es um die Auswirkungen des maternalen Alters auf die embryonale Mortalität und die juvenile Entwicklung der Brut. Im dritten Studienteil werden die Auswirkungen der Verweildauer in der Spermatheca auf die embryonale Mortalität, Embryonenqualität und Larvenentwicklung der Nachkommen untersucht. Der Samen aus den Spermatheken älterer Bienen weist andere Bewegungsmuster, eine geringere Geschwindigkeit und eine anderen Enzymaktivität auf als der Samen, der aus den Spermatheken junger Königinnen gewonnen wurde. Ein altersbedingtes Nachlassen der Fertlität ist daraus zu erklären. Im Laufe von zwei Jahren wurde die embryonale Entwicklung und das Larvenwachstum von Nachkommen unterschiedlich alter Königinnen untersucht (2-jährige bis frisch begattete Königinnen). Ältere Königinnen legten kleinere Eier und deren Nachkommen zeigten eine signifikant höhere Mortalitätsrate und kleinere Entwicklungsstadien als die Nachkommen jüngerer Königinnen. In einer weiteren Studie wurde die embryonale Mortalität und die Embryonalentwicklung von Nachkommen, die aus älteren Samen entstanden, untersucht. Dabei wurde der Samen aus den Spermatheken von alten und jungen begatteten Königin entnommen und jungfräuliche Königinnen übertragen. um das Alter der Königin auszugleichen. Bei der Untersuchung wurde eine höhere embryonale Mortalität und generell, zu gewissen Entwicklungszeiten signifikant, kleine Entwicklungsstadien bei den Königinnen festgestellt, die mit dem älteren Samen befruchtet wurden. Der relative Anteil an früher und später embryonaler Mortalität war auch zwischen den beiden Spermien-Alterlassen signifikant unterschiedlich. Die insgesamt hohe embryonale Mortalität auch in der Kontrollgruppe (Königinnen besamt mit Sperma aus den Spermathecen junger Königinnen) belegt, dass die Methode der Samenextraktion und Reinsemination einen großen Einfluß auf die Embryonalentwicklung hatte. Auch das Phänomen „leerer Eier“, welches in beiden Gruppen in gleicher Frequenz vorgefunden wurde, ist möglicherweise durch diese Methode bedingt. / This study on the honey bee, Apis mellifera, consists of three major parts. The first involves the characteristics of the spermathecal content of old and young honey bee queen. The second examines maternal age effects on embryonic mortality and juvenile development of offspring in the honey bee. The third investigates on the impact of semen age on early embryonic mortality, embryo quality and larvae development in the honey bee. Semen collected from the spermatheca of old queen bees show different sperm movement patterns and slower speed than sperm from the spermathecae of young queens. This ability is possibly related to different enzyme activities and metabolisms found in the spermathecal contents of differently aged queens. The embryonic development and larval growth rate have been examined with regard to queen honey bees of different ages (2-year-old to freshly mated queens) during two years (2005 and 2006). Early embryonic mortality “EEM” has been found to be higher within the eggs from old queens than in those from younger queens. Egg volume, consequently embryo size, reduces as queen’s age. A further investigates embryonic mortality in offspring originating from older semen. This has been carried out by extracting the semen from the spermatheca of an old or/and young mated queen and re-inseminating it into a virgin queen, in order to adjust for queen age. The investigation show higher embryonic mortality in the offspring from virgin queens inseminated with semen extracted from older queens than with semen from younger queens. The relative percentage of early and late embryonic mortality within the groups was different between queens re-inseminated with aged semen. High embryonic mortality in the control semen ages may be affected by the method of extracting from semen out of the spermatheca and re-inseminating it into a virgin queen. Empty egg phenomenon, which has been found in both groups, may be related to this technique
9

Echecs précoces de gestation chez la vache laitière de race Holstein : incidences, implication dans la baisse de fertilité et facteurs de risque / Early pregnancy failures in Holstein dairy cows : Incidence, Role in the decrease fertility, risk factors

Ledoux, Dorothée 08 July 2011 (has links)
Actuellement en France et aux Etats-Unis, seules 30 à 35 % des premières inséminations artificielles chez la vache Holstein aboutissent à un vêlage. Les échecs de gestation ont lieu le plus souvent au cours du développement embryonnaire (Non-Fécondation-Mortalité Embryonnaire Précoce (NF-MEP) entre 0 et 16 jours, Mortalité Embryonnaire Tardive (MET) entre 16 et 45 jours après insémination). Ces échecs précoces de gestation expliquent en grande partie les différences de fertilité observées en France entre la race Holstein et les autres races plus fertiles. Les facteurs de risque de l'interruption de la gestation sont multiples : liés à l'animal, à l'environnement et à la conduite de l'élevage. Trois facteurs cependant ont évolué au cours du temps pour les vaches Holstein : le potentiel génétique, les anomalies de reprise de la cyclicité après vêlage, le déficit énergétique en début de lactation. Notre objectif a été d'identifier l'influence de ces trois facteurs sur les échecs précoces de gestation après première insémination postpartum chez la vache de race Holstein. Le potentiel génétique a été associé à l'incidence de NF-MEP et de MET. Les phases lutéales prolongées sembleraient être à l'origine d'une augmentation d'incidence de MET. Le déficit énergétique a eu un effet sur la NF-MEP et sur la MET. L'effet du déficit énergétique postpartum sur la qualité des ovocytes au moment de la mise à la reproduction reste hypothétique. Notre travail sur les échecs précoces de gestation a permis de contribuer à fournir des outils d'amélioration de conduite d'élevage aux professionnels. / Currently, in France and the United States of America, only 30-35 % of first artificial inseminations in Holstein cows result in a calving. Pregnancy failure mainly occurs during embryonic development (fertilization failure - early embryonic mortality (FF-EEM) between D0 and D16 or late embryonic mortality (LEM) between D16 and D45 after insemination). Early pregnancy failure explains the majority of the differences in fertility between the Holstein breed and the other breeds in France, which are more fertile. There are numerous risk factors which cause pregnancy failure: animal, environmental and farm management factors. There are however, three factors which have been modified over time in Holstein cows: genetic merit, abnormal patterns of resumption of cyclicity and negative postpartum energy balance (NEB). Our objective was to identify the relationships between these three factors and early pregnancy failure after first postpartum insemination in Holstein dairy cows. Genetic merit was related to the incidence of FF-EEM and LEM. Prolonged luteal phases seemed to increase the incidence of LEM. The NEB was associated with FF-EEM and LEM. The impact of NEB on oocyte quality during the breeding period remains unclear. Our early pregnancy failure studies have helped to provide some tools to improve farm management.
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Malformações em pequenos ruminantes. / Malformations in small ruminants.

SANTOS, José Rômulo Soares dos. 04 September 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-09-04T23:45:22Z No. of bitstreams: 1 JOSÉ RÔMULO SOARES DOS SANTOS - TESE PPGMV 2012..pdf: 499950 bytes, checksum: a58df169790a0820def666327bad8f42 (MD5) / Made available in DSpace on 2018-09-04T23:45:22Z (GMT). No. of bitstreams: 1 JOSÉ RÔMULO SOARES DOS SANTOS - TESE PPGMV 2012..pdf: 499950 bytes, checksum: a58df169790a0820def666327bad8f42 (MD5) Previous issue date: 2012-12-20 / Esta tese inclui uma revisão de literatura e dois artigos. O primeiro capítulo é uma revisão que abrange princípios gerais da teratologia, a epidemiologia, o diagnóstico, a clínica e a patologia das malformações em pequenos ruminantes. No artigo que corresponde ao segundo capítulo, foi estudado a teratogenicidade de Mimosa tenuiflora. Quinze ovelhas, distribuídas em dois grupos foram introduzidas em área invadida pela planta. O Grupo 1, com seis ovelhas prenhes, foi introduzido na área experimental 20 dias após o acasalamento. O Grupo 2, formado por nove ovelhas não prenhes e um carneiro, foi introduzido na área experimental no início do experimento. A cada 15 dias eram realizados exames ultrassonográficos para acompanhamento da gestação. No Grupo 1, três ovelhas abortaram, cada uma um feto sem malformações. Outra ovelha pariu dois cordeiros, um com hiperflexão na articulação interfalangeana proximal no membro torácico direito e outro sem malformações. Outra ovelha pariu um cordeiro com hiperflexão dos dois membros pélvicos na região da articulação tarsometatársica. No grupo 2, uma ovelha abortou um feto sem malformações e cinco pariram cordeiros normais. Três das ovelhas desse grupo não emprenharam durante todo o período experimental, mostrando retornos repetidos ao cio, sugerindo perda embrionária. Concluiu-se que M. tenuiflora, além de causar malformações causa, também, mortalidade embrionária e abortos em ovelhas. No terceiro capitulo, o artigo relata os achados clínicos e patológicos de um caprino com lisencefalia e hipoplasia cerebelar. No exame físico, esse caprino de 30 dias, apresentava incoordenação e incapacidade de ficar em pé, decúbito esternal permanente, ataxia, ausência do reflexo de ameaça, tremores de intenção e nistagmo. Após 11 dias de internamento o caprino foi eutanasiado e necropsiado. Na necropsia, o cérebro não apresentava giros e sulcos e o cerebelo estava reduzido de tamanho. Histologicamente, em todo o córtex cerebral, a substância cinzenta estava mais espessa e a substância branca mais fina que o normal. Os neurônios estavam distribuídos de forma aleatória na substância cinzenta. No cerebelo, as camadas estavam desorganizadas, com localização heterotópica das células. Os achados macroscópicos e histológicos são característicos de lisencefalia e hipoplasia cerebelar. Lisencefalia é uma doença rara na medicina veterinária e não tinha sido descrita em caprinos. / This thesis includes a review and two papers. The first chapter is a review about general principles of teratology and epidemiology, diagnosis, clinical signs and pathology of malformations in small ruminants. The second chapter is a paper that studied the teratogenicity of Mimosa tenuiflora. Fifteen sheep, divided into two groups, were introduced into an area invaded by the plant. Group 1 consisted of six pregnant ewes that were introduced into the experimental area 20 days after mating. Group 2 consisted of nine non pregnant sheep and a ram introduced into the area at the start of the experiment. Every 15 days each sheep was examined by ultrasound to control pregnancy. In Group 1, three sheep aborted single fetuses without malformations. One sheep delivered two lambs, one with hyperflexion of the proximal inter-phalangeal joint of the right forelimb and another without malformations. Another sheep delivered a lamb with a hyperflexion of both hindlimbs in the region of the tarsal-metatarsal joint. Only one sheep delivered a normal lamb. In Group 2, one sheep aborted a fetus without malformations and five delivered normal lambs. Three sheep of this group returned to estrus repeatedly and did not get pregnant during the mating period, suggesting embryonic loss. It is concluded that M. tenuiflora cause malformations, embryonic mortality and abortion in sheep. In the third chapter, the paper relates a case of lissencephaly and cerebellar hypoplasia in a goat. The goat presented sternal recumbence, absent menace response, intention tremors, ataxia, and nystagmus. It was euthanized and necropsied after been hospitalized during eleven days. At necropsy, the surface of the brain was smooth, cerebral sulci and gyri were absent, and the cerebellum was reduced in size. Histologically, in all cerebral cortex, the grey matter was thicker and the white matter was thinner than normal. The neurons were arranged randomly in the grey matter. In the cerebellum, the layers were disorganized and there was heterotopy of the cells. The histologic and gross lesions are characteristic of lissencephaly associated with cerebellar hypoplasia. Lissencephaly is a rare disease in veterinary medicine and had not been reported previously in goats.

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