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Impacts de la prédation sur un grand herbivore aux niveaux de l'individu et de la populationBarnier, Florian 24 September 2012 (has links) (PDF)
La prédation peut avoir des effets très importants à la fois sur l'écologie ainsi que sur l'évolution des communautés biologiques. Elle peut notamment être une force sélective favorisant des prédateurs plus efficaces et des proies moins vulnérables. De plus, des études montrent que les prédateurs agissent sur les proies, non seulement directement en les tuant, mais qu'ils peuvent également influencer le comportement des proies et induire des réponses physiologiques ou morphologiques. Pourtant, aujourd'hui, encore peu de choses sont connues sur comment les prédateurs peuvent influencer les populations de proies, notamment chez les grands herbivores. Les études les plus détaillées sur les grands herbivores sont en effet situées dans l'hémisphère Nord, souvent dans des endroits où ces herbivores n'ont plus de prédateurs. Lors de cette thèse j'ai étudié une population de grands herbivores et l'impact de la prédation sur celle-ci : la population de zèbres des plaines (Equus quagga) dans le parc national de Hwange au Zimbabwe et son interaction avec les lions. J'ai étudié la dynamique de populations des zèbres dans la zone d'étude, mais j'ai également travaillé sur le zèbre au niveau individuel, en tentant de mieux comprendre quels étaient les comportements anti-prédateurs utilisés par les zèbres, ainsi que leurs coûts potentiels, tout en m'intéressant aux différences entre individus. Cette population de zèbres est fortement impactée par la prédation, de manière à la fois directe et indirecte, et les comportements anti-prédateurs mis en place par les zèbres sont coûteux.
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Avaliação de parâmetros hemogasométricos e bioquímicos durante infusão contínua de detomidina em equinos em estaçãoSerpa, Priscila Beatriz da Silva January 2011 (has links)
A detomidina é um agonistas α2 adrenérgicos amplamente empregado para sedação, analgesia e medicação pré-anestésica em equinos. A ativação dos receptores α2 distribuídos no Sistema Nervoso Central e Periférico provoca uma série de alterações fisiológicas, tais como bradicardia, bloqueio átrio-ventricular, diminuição do débito cardíaco, bradipnéia, inibição da secreção de insulina, hiperglicemia, diminuição da motilidade gastrointestinal, relaxamento da musculatura esquelética, diminuição da secreção de ACTH e ADH, hipnose e sedação. Para investigar a interferência da detomidina sobre alguns parâmetros fisiológicos e metabólicos, seis equinos foram mantidos em estação e submetidos a uma hora de infusão contínua de detomidina na dose de 20 μg.kg-1.h-1 , servindo como seus próprios controles. Foram avaliados frequência cardíaca (FC), frequência respiratória (FR), pressão arterial média (PAM), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), tempo de preenchimento capilar (TPC), temperatura retal (TR), hemogasometria sanguínea, glicose e lactato plasmáticos, insulina sérica, proteína plasmática total (PPT), hematócrito (Ht), hemoblobina (Hb), saturação de oxigênio (SO2), bicarbonato, sódio, potássio, e cálcio ionizado sanguíneos, glicogênio e lactato muscular e realizada urinálise, antes da infusão contínua de detomidina (T0), 20 minutos após (T20), 40 minutos após (T40) e 60 minutos após (T60), quando a infusão foi descontinuada. Uma hora após o término da infusão, foi realizada uma última coleta (T120). As variáveis foram submetidas à ANOVA, teste t de Student, teste de Tukey e teste de Friedman de acordo com o tipo de variável com nível de confiança de 95%. Os resultados indicaram diminuição estatisticamente significativa da FC, FR, Ht, Hb, cálcio ionizado e glicogênio muscular, além de aumento significativo da glicose, lactato e bicarbonato sanguíneos. Não houve diferença estatística significativa nas variáveis TPC, TR, PAM, PAS, PAD, PaO2, PaCO2, pH arterial, SO2, insulina sérica, PPT, lactato muscular e variáveis urinárias. A utilização de uma infusão contínua de detomidina na dose preconizada neste estudo promoveu um período de sedação prolongada em equinos em estação, com ocorrência de efeitos adversos moderados e sem significância clínica em animais hígidos. A hipoinsulinemia provocada por esta droga de fato influencia o metabolismo energético através da mobilização de reservas observada e do aumento de lactato sérico. / The detomidine is an α2 adrenergic agonist widely used for sedation, analgesia and premedication in horses. The activation of α2 receptors distributed in Central and Peripheral Nervous System causes a series of changes, such as bradycardia, atrioventricular block, decreased cardiac output, bradypnea, inhibition of insulin secretion, hyperglycemia, decreased gastrointestinal motility, relaxation of skeletal muscle, decreased secretion of ACTH and ADH, hypnosis and sedation. To investigate the interference of detomidine on some physiological and metabolic parameters, six horses were subjected to one hour of continuous rate infusion of detomidine at a dose of 20 μg.kg-1.h-1 and served as their own controls. We assessed heart rate (FC), respiratory rate (FR), mean arterial pressure (PAM), systolic blood pressure (PAS), diastolic blood pressure (PAD), capillary refill time (TPC), rectal temperature (TR), blood gases, blood glucose, plasma lactate, serum insulin, total plasma protein (PPT), hematocrit (Ht), hemoblobin (Hb), oxygen saturation (SO2), bicarbonate, sodium, potassium, ionized calcium, muscle glycogen and muscle lactate, and urinalysis performed before the infusion of detomidine (T0), after 20 minutes (T20), 40 minutes after (T40) and 60 minutes after (T60), when the infusion was discontinued. One hour after the infusion was performed a last collection (T120). The variables were submitted to ANOVA, Student's t test, Tukey’s test and Friedman’s test according to the type of variable with a confidence level of 95%. The continuous rate infusion of detomidine resulted in a significant decrease in FC, FR, Ht, Hb, ionized calcium and muscle glycogen, and a significant increase in glucose, plasma lactate and bicarbonate. There was no statistically significant difference in the variables TPC, TR, PAM, PAS, PAD, blood gases, serum insulin, PPT, muscle lactate and urinary variables. The use of a continuous rate infusion of detomidina in the recommended dose in this study promoted a prolonged sedation, with moderate adverse effects with no clinical significance in healthy animals. The hypoinsulinemia caused by this drug did influence energetic metabolism through the mobilization of reserves and the observed increase in plasma lactate.
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Avaliação de parâmetros hemogasométricos e bioquímicos durante infusão contínua de detomidina em equinos em estaçãoSerpa, Priscila Beatriz da Silva January 2011 (has links)
A detomidina é um agonistas α2 adrenérgicos amplamente empregado para sedação, analgesia e medicação pré-anestésica em equinos. A ativação dos receptores α2 distribuídos no Sistema Nervoso Central e Periférico provoca uma série de alterações fisiológicas, tais como bradicardia, bloqueio átrio-ventricular, diminuição do débito cardíaco, bradipnéia, inibição da secreção de insulina, hiperglicemia, diminuição da motilidade gastrointestinal, relaxamento da musculatura esquelética, diminuição da secreção de ACTH e ADH, hipnose e sedação. Para investigar a interferência da detomidina sobre alguns parâmetros fisiológicos e metabólicos, seis equinos foram mantidos em estação e submetidos a uma hora de infusão contínua de detomidina na dose de 20 μg.kg-1.h-1 , servindo como seus próprios controles. Foram avaliados frequência cardíaca (FC), frequência respiratória (FR), pressão arterial média (PAM), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), tempo de preenchimento capilar (TPC), temperatura retal (TR), hemogasometria sanguínea, glicose e lactato plasmáticos, insulina sérica, proteína plasmática total (PPT), hematócrito (Ht), hemoblobina (Hb), saturação de oxigênio (SO2), bicarbonato, sódio, potássio, e cálcio ionizado sanguíneos, glicogênio e lactato muscular e realizada urinálise, antes da infusão contínua de detomidina (T0), 20 minutos após (T20), 40 minutos após (T40) e 60 minutos após (T60), quando a infusão foi descontinuada. Uma hora após o término da infusão, foi realizada uma última coleta (T120). As variáveis foram submetidas à ANOVA, teste t de Student, teste de Tukey e teste de Friedman de acordo com o tipo de variável com nível de confiança de 95%. Os resultados indicaram diminuição estatisticamente significativa da FC, FR, Ht, Hb, cálcio ionizado e glicogênio muscular, além de aumento significativo da glicose, lactato e bicarbonato sanguíneos. Não houve diferença estatística significativa nas variáveis TPC, TR, PAM, PAS, PAD, PaO2, PaCO2, pH arterial, SO2, insulina sérica, PPT, lactato muscular e variáveis urinárias. A utilização de uma infusão contínua de detomidina na dose preconizada neste estudo promoveu um período de sedação prolongada em equinos em estação, com ocorrência de efeitos adversos moderados e sem significância clínica em animais hígidos. A hipoinsulinemia provocada por esta droga de fato influencia o metabolismo energético através da mobilização de reservas observada e do aumento de lactato sérico. / The detomidine is an α2 adrenergic agonist widely used for sedation, analgesia and premedication in horses. The activation of α2 receptors distributed in Central and Peripheral Nervous System causes a series of changes, such as bradycardia, atrioventricular block, decreased cardiac output, bradypnea, inhibition of insulin secretion, hyperglycemia, decreased gastrointestinal motility, relaxation of skeletal muscle, decreased secretion of ACTH and ADH, hypnosis and sedation. To investigate the interference of detomidine on some physiological and metabolic parameters, six horses were subjected to one hour of continuous rate infusion of detomidine at a dose of 20 μg.kg-1.h-1 and served as their own controls. We assessed heart rate (FC), respiratory rate (FR), mean arterial pressure (PAM), systolic blood pressure (PAS), diastolic blood pressure (PAD), capillary refill time (TPC), rectal temperature (TR), blood gases, blood glucose, plasma lactate, serum insulin, total plasma protein (PPT), hematocrit (Ht), hemoblobin (Hb), oxygen saturation (SO2), bicarbonate, sodium, potassium, ionized calcium, muscle glycogen and muscle lactate, and urinalysis performed before the infusion of detomidine (T0), after 20 minutes (T20), 40 minutes after (T40) and 60 minutes after (T60), when the infusion was discontinued. One hour after the infusion was performed a last collection (T120). The variables were submitted to ANOVA, Student's t test, Tukey’s test and Friedman’s test according to the type of variable with a confidence level of 95%. The continuous rate infusion of detomidine resulted in a significant decrease in FC, FR, Ht, Hb, ionized calcium and muscle glycogen, and a significant increase in glucose, plasma lactate and bicarbonate. There was no statistically significant difference in the variables TPC, TR, PAM, PAS, PAD, blood gases, serum insulin, PPT, muscle lactate and urinary variables. The use of a continuous rate infusion of detomidina in the recommended dose in this study promoted a prolonged sedation, with moderate adverse effects with no clinical significance in healthy animals. The hypoinsulinemia caused by this drug did influence energetic metabolism through the mobilization of reserves and the observed increase in plasma lactate.
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Aspectos epidemiológicos de alterações do aparelho locomotor e uso da arnica montana no tratamento da tendinite experimental em eqüinos / Epidemiological aspects of alterations in the locomotor aparatus and use of arnica montana in the treatment of equine experimental tendinitisMARANHÃO, Renata de Pino Albuquerque 29 September 2008 (has links)
Made available in DSpace on 2014-07-29T15:13:40Z (GMT). No. of bitstreams: 1
Tese Renata de Pino A Maranhao.pdf: 884544 bytes, checksum: 6285e47eeba35dfba3fc97c0c9f7d235 (MD5)
Previous issue date: 2008-09-29 / Dentre as enfermidades do aparelho locomotor, a tendinite eqüina representa
parcela significativa das ocorrências clínicas de rotina. Os objetivos deste trabalho
foram realizar um estudo da afecções do aparelho locomotor eqüino nos animais
do Primeiro Regimento de Cavalaria de Guarda e testar um protocolo terapêutico
com gel de Arnica montana como princípio ativo associado ao ultra-som
terapêutico (UST) na tendinite eqüina induzida por colagenase. Verificou-se nos
arquivos do 1º RCG, que os traumatismos contusos e cortantes foram as
situações patológicas mais freqüentes, predominando nos animais do cerimonial
militar. A tendinite dos flexores foi mais freqüente nos animais de pólo e do
cerimonial, enquanto que a desmite do suspensório afetou mais os animais de
salto. Na fase experimental, a tendinite foi induzida pela aplicação de colagenase
no terço médio do tendão flexor digital superficial de quinze éguas, distribuídas em
três grupos. No grupo GC, utilizou-se o ultra-som terapêutico (UST) desligado e
gel de contato, no grupo GA, o gel contendo Arnica montana a 20% associado ao
UST desligado e no grupo GAU, empregou-se gel de Arnica montana a 20%,
porém com o UST ligado, na dose de 0,5watt/cm2, no modo contínuo, por cinco
minutos. Observou-se no grupo GA uma redução precoce do edema metacarpiano
e menor área de lesão ultra-sonográfica, enquanto que no grupo GAU a área total
do tendão foi maior ao final do período. Concluiu-se que a ocorrência de
enfermidades do aparelho locomotor nos eqüinos no 1º RCG é alta, estando
relacionada principalmente às atividades desempenhadas pelos animais. Além
disso, o gel de arnica utilizado isoladamente foi mais eficaz na redução dos sinais
clínicos e da área da lesão.
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Akustická detekce potencionálního predátora u koně domácího (Equus caballus) / The acoustic detection of potential predator in domestic horse (Equus caballus)Vidimská, Tereza January 2017 (has links)
Equidae belong to a group of large herbivores, which survival in natural environment depends beside others on their capability of fast predator recognition and detection. They can sensually recognise a possible threat in advance and react by immediate escape, which increases their survival. Also domestic horses still show very sensitive reaction to sudden (unexpected) stimuli. So we assume, that the ability to detect predator immediately is conserved despite of the long domestication process. The supportive indirect evidence is given by the successful breeding of the feral herds all over the world. However, studies showing the direct reaction of domestic horse toward the canids (as the most common predators), are still absent. Aim of the work was to find, if the horses (Equus caballus) could recognize acoustic sign of dogs like predators and if they could recognize the level of potential threat according to the number of predators, similarly as their wild ancestors. The recordings of barking of big dog breeds were obtained and modified. The final recording contained the set of barking coming from one individual or three different. The recording was played to the experimental horses, under controled conditions, together with white sound as a control. The reactions were recorded. Altogether 12 horses out of...
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Akustická detekce potencionálního predátora u koně domácího (Equus caballus) / The acoustic detection of potential predator in domestic horse (Equus caballus)Vidimská, Tereza January 2018 (has links)
Equidae belong to a group of large herbivores, which survival in natural environment depends beside others on their capability of fast predator recognition and detection. They can sensually recognise a possible threat in advance and react by immediate escape, which increases their survival. Also domestic horses still show very sensitive reaction to sudden (unexpected) stimuli. So we assume, that the ability to detect predator immediately is conserved despite of the long domestication process. The supportive indirect evidence is given by the successful breeding of the feral herds all over the world. However, studies showing the direct reaction of domestic horse toward the canids (as the most common predators), are still absent. Aim of the work was to find, if the horses (Equus caballus) could recognize acoustic sign of dogs like predators and if they could recognize the level of potential threat according to the number of predators, similarly as their wild ancestors. The recordings of barking of big dog breeds were obtained and modified. The final recording contained the set of barking coming from one individual or three different. The recording was played to the experimental horses, under controlled conditions, together with white sound as a control. The reactions were recorded. Altogether 12...
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Digestibility of Two Complete Pelleted Diets by the Horse (Equus caballus) as a Model Animal for Nondomestic Hindgut FermentersSchwartz, Emily M. 01 December 2015 (has links) (PDF)
Estimating nutrient and energy requirements of exotic animals is a necessary component of nutrition management in zoos and other wildlife facilities. In the absence of species-specific data, domestic animal models are often referenced. Herbivorous hindgut fermenters, such as horses, zebra, and rhinoceros, rely on microbial fermentation in the cecum and colon to utilize dietary structural carbohydrates. The study objective was to measure the digestible energy of two (LOW, HIGH) complete pelleted diets by the horse as a model for nondomestic hindgut fermenters. Seven, individually housed, adult Quarter Horse (Equus caballus) geldings were assigned to one of two diets as 100% of intake in a randomized crossover design. Experimental diets both contained similar ingredients including soybean oil as an added source of supplemental fat (LOW 1.7%, HIGH 6.9%). Diets differed in predicted digestible energy (LOW 2.29 Mcal/kg, HIGH 2.85 Mcal/kg, DE), ether extract (LOW 4.00%, HIGH 7.41%, EE), and acid detergent fiber (LOW 33.7%, HIGH 26.2%, ADF). Daily feed quantities were offered at 33.3 kcal DE BWkg-1 equally distributed over three meals to maintain target BW. Daily feed intake was quantified. Horses had ab libitum access to water. Horses were transitioned from all forage to 100% test diet over 14 d, acclimated to the test feed for 19 d prior to 4 d acclimation and 6 d total fecal collection using hygiene collection harnesses (Equi-San Marketing Pty Ltd). Diet transition between periods occurred over 8 d. Total fecal output was quantified every 8 h, thoroughly mixed and 10% of measured mass output was subsampled for further analysis. Body weights (BW) recorded weekly did not change significantly throughout the trial (P = 0.420). Apparent digestibility of diet within horse and day was evaluated by a nested ANOVA (Minitab 16). The apparent digestibility of EE (P < 0.000), neutral detergent fiber (P = 0.008), and ADF (P = 0.002) differed between the two diets. Apparent digestibility of DM (P = 0.137), OM (P = 0.140), and GE (P = 0.418) were not different. Excess fat not digested and absorbed in the small intestine (by-pass fat) will enter the hindgut and may cause disruption of normal microbial activity. Additionally soybean oil, when consumed in quantities that allow by-pass to occur, has been shown to have a negative effect on fiber digestibility in hindgut fermenters. A negative effect on fiber digestibility in the higher fat diet could result in diets closer in DM, OM, and GE digestibility than initially predicted. The NRC (2007) recommends that no more than 0.7 g/kg BW/d of soybean oil be fed to the horse. The HIGH diet provided 0.91 g/kg BW/d soybean oil. Feeds that contain concentrations higher than recommended may not be appropriate as the sole dietary ingredient of hindgut fermenters. Further studies are needed to evaluate the use of soybean oil and to determine the threshold at which soybean oil will begin to suppress hindgut fiber digestion. In vivo measurements of digestibility in model species may provide useful benchmarks from which diets for nondomestic hindgut fermenters, as well as horses, may be formulated.
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The horse in Roman societyLawrie, Margaret Ruth 30 November 2005 (has links)
This dissertation presents an investigation of the place of the horse in Roman society,
within the context of its roles as equus publicus, which derived ultimately from that of the cavalry mount, and race-horse. Consideration of the ceremonial role of the horse
provides a clearer understanding of the value placed upon horses and horsemanship in
the Roman world, thus permitting inferences to be drawn regarding the role played by the
horse in the development of the equester ordo. Evidence is drawn from both literary and
archaeological sources to shed light on the management and training of the horses of
equestrian Rome. Chariot racing is also re-examined from the perspective of its equine
players, and evidence is drawn from various sources to provide a more complete picture
of the Roman horse-racing industry as a social structure. The importance of the racehorse
in Roman society is examined and the symbolism of the victorious horse as
represented in Roman art is discussed. / Classics & Modern European Languages / M.A. (Ancient Languages and Cultures)
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Chondrodysplasia-Like Dwarfism in the Miniature HorseEberth, John E 01 January 2013 (has links)
Dwarfism is considered one of the most recognized congenital defects of animals and humans and can be hereditary or sporadic in cause and expression. There are two general morphologic categories within this vastly diverse disease. These categories are disproportionate and proportionate dwarfism and within each of these there are numerous phenotypes which have been extensively described in humans, and to a lesser extent in dogs, cattle, mice, chickens, and other domestic species. Ponies and Miniature horses largely differ from full size horses only by their stature. Ponies are often defined as those whose height is not greater than 14.2 hands; however the maximum height for Miniature horses is constitutionally defined as 8.2 hands. Dwarfism is not considered a desirable genetic trait for Miniature horses. A majority of these conformationally inferior horses showed consistent physical abnormalities typical of disproportionate dwarfisms as seen in other mammal species. A whole genome scan with the Illumina Equine SNP50 chip clearly implicated a region on ECA1 as being associated with dwarfism of horses. The region implicated on the horse chromosome 1 (Equus Caballus; ECA1) contained a candidate gene for dwarfism, aggrecan (ACAN). Mutations were found in Exons 2, 6, 11 and 15 with each mutation associated with a distinct type of dwarfism. These mutations are independently transmitted throughout the population. Absence of normal homozygotes for these mutations and absence of normal horses which were heterozygous for these mutations indicated that these alleles caused dwarfism in those genotypes. These genotypes did not explain all observed dwarves in this population.
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Body size relationships and reproductive ecology of female feral horses on Sable Island, Nova Scotia2015 March 1900 (has links)
Body size is an important determinant of reproduction in capital breeding animals, including
large mammals. However, it is not always practical to hand-measure body size of free-ranging
species. In recent years, parallel-laser photogrammetry has been used to obtain remote estimates
of body size for some animals, though it remains unknown how well this technique might
capture variation in curvilinear body features or if the distance between parallel-laser calipers is
altered when projected onto a curved surface. In this thesis, I describe a photogrammetric system
that may be useful for obtaining body-size measurements from unrestrained large mammals that
permit approach, using domestic horses (Equus ferus caballus) as a model (Chapter 2). I then
apply this technique in the field to a wild (feral) population of horses at Sable Island National
Park Reserve, Nova Scotia, Canada, where I include body size measurements as variables in a
detailed analysis of factors affecting reproduction in females (Chapter 3). Using my parallel-laser
photogrammetric system, I show how curvilinear hand-measurements (e.g., across the barrel of a
horse) are stongly correlated with their respective linear photogrammetric estimates (R2 ≥ 0.998),
and most photogrammetric estimates using my system had high reliability. Using three variables
of body size, photogrammetric estimates and hand-measurements explained 86.0% and 96.2%,
respectively, of the variation in body weight of a sample of domestic Newfoundland ponies. On
Sable Island, Nova Scotia, I examined the relationship of numerous variables (including skeletal
body size and body condition) with the probability of yearly reproductive success for female
Sable Island horses (years 2008–2012), where I define reproductive success as production of an
offspring surviving to one year of age. Age class was a dominant factor predicting reproductive
success, as expected from trends previously associated with body size or reproductive experience
iii
in other populations. Age-class specific energy budgets or social and sexual behaviour caused a
more pronounced relationship with body condition at parturition in sub-adults, and body
condition at conception and stability of consort relationships were associated with reproductive
success in adults. In addition, relationships with local density suggested limited forage around
the time of conception and limited water during lactation might also influence reproductive
success in adult females. Although relationships were evident for age class, which is correlated
with body size, reproductive success was not related to skeletal body size, past reproductive
experience, age of primiparity, or band structure. The capital breeding strategy and year-round
social associations seen in horses make their reproductive ecology a combination of patterns
observed for large ungulates and social primates.
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