Tesi sul tema "Rabbits"

Two populations of rabbits (Oryctolaqus cuniculus) were investigated to see whether polygynous, multi-male groups formed in the absence of large multi-entranced warrens. They did not. Rabbits neither gathered in space nor time. The small warrens were spread out evenly across homogeneous patches and the females were well spaced out. Monogamy, distinguished by a battery of tests, was prevalent, with the more dominant males as 'mate' rabbits. That the polygyny frequently mentioned in the literature was a result of male dominance and female defense was considered. The genetic structure of each population was investigated by taking blood from rabbits and having it analysed electrophoretically and for immunoglobulins. A method for assessing relatedness between groups of pairs of animals was implemented, then validated and developed with Monte Carlo simulations. With the seven polymorphic allele obtained, no non-zero relatedness was found but it was sometimes possible to exclude high relatedness. The bearing of sociality on vigilance during feeding was investigated. Although a rabbit's vigilance decreased as its 'mate' approached, the presence of other rabbits was correlated with increased vigilance. It was concluded that the need for social vigilance outweighed the benefit of 'many eyes' watching for predators. This conclusion was tested by experiment, using stuffed animals as stimuli. Rabbits increased their vigilance during grazing bouts both by increasing the length and frequency of scans. Scans could be short or long: the probability of ending a scan decreased sharply at a certain point; a form of positive feedback. The durations of short 'maintenance' scans were dependent on chewlength (the amount of food in the mouth). This fitted a timesharing definition as supported by experiment. Long scans in response to a visible threat did not involve chewing.

There is a need to develop a range different VLP for use as nanoscale templates and vaccines. The aim of this research was to develop RHDV VLP as a versatile vaccine delivery system easily modified for use against a wide range of different diseases. Production of Rabbit haemorrhagic disease virus (RHDV) capsid protein in a baculovirus system led to the self-assembly of Virus-like Particles (VLP) that could be purified to greater than 99% purity using simple methods. The capsid gene, vp60, can be manipulated genetically to incorporate immunogenic peptide sequences or a functional DNA-binding site. Fusion of these small epitopes to VP60 was well tolerated, forming VLP and greatly enhanced the presentation of peptide to, and activation of CD4+ T helper cell hybridoma. To avoid constraints imposed on chimeric VLP and dramatically increase the versatility of RHDV VLP, rapid conjugation of antigen was carried out, employing the hetero-bifunctional chemical linker, sulpho-SMCC. Incorporation of sulfhydral groups by design or treatment with SATA allowed for great versatility, in turn enabling many diverse peptides and proteins to be conjugated to VLP. RHDV VLP and consequently the conjugated GFP antigen were efficiently taken up by DC with more than 85% of DC positive for GFP by flow cytometry. This was also visualised by confocal microscopy and electron microscopy of both gold- labelled VLP and conjugated antigen. RHDV VLP conjugate was shown to induce the significant up regulation of the activation markers CD40, CD80, CD86 and MHC class II on the surface of dendritic cells (DC). As well, DC pulsed with RHDV VLP/OVA effectively presented OVA to both CD4+ and CD8+ T cells transgenic for respective peptide-specific T cell receptors, eliciting a greater proliferative response in both T cell subsets than antigen delivered alone. The surface accessibility of peptides on VLP was demonstrated, while administration of VLP/Ovalbumin (OVA) conjugate in mice was shown to evoke very high titre antibody responses specific for conjugated antigen. VLP/OVA conjugates were also shown to induce IFN-γ production and OVA-specific cytotoxic killing in vivo, of up to 80% of fluorescently labelled, adoptively transferred target cells. No distinguishable cytotoxicity was detected in unimmunised control mice. This assay was also used to demonstrate the necessity for antigen to be conjugated to VLP, as antigen mixed with VLP induced only sub-optimal killing. To investigate the anti-tumour effects, mice vaccinated with VLP conjugated to OVA protein, CD4+ or CD8+ T cell OVA epitopes were inoculated with B16- OVA tumour cells and monitored for tumour growth. Untreated control mice had to be sacrificed by day 19, while mice immunised with either VLP/OVA or VLP conjugated with both CD4+ and CD8+ OVA epitopes, showed a significant delay in tumour growth (P = 0.0002), with one mouse remaining free of palpable tumour until day 92. These results show that RHDV VLP can be easily produced and purified and demonstrate the versatility of this RHDV capsid. Rapid conjugation techniques allowed the modification of VLP with both peptide and protein rendered these antigens highly immunogenic, stimulating both humoral and cell-mediated immunity targeted against conjugated antigens of choice. The versatility and immune stimulating properties of RHDV VLP provides a molecular tool with almost limitless applications within the fields of nanotechnology and immunology.

Olfactory behaviour in the European rabbit (Oryctolagus cuniculus) has been studied extensively under laboratory and semi-natural conditions. Results of observations on aspects of the olfactory behaviour of a free-living population of rabbits are presented. To facilitate interpretation of these results, considerable preliminary information about the population was collected. The study was conducted over a three year period on the Isle of May off the east coast of Scotland. A total of 326 rabbits were trapped and marked to permit identification in the field, and data on sex, age and social status of these individuals was collated. Data on the overall structure and fluctuations in the population are presented. The social organisation and home ranges of rabbits at four study sites throughout the three years are described. Observations indicate that the social organisation of free-living populations is more complex and variable than previous descriptions of semi-natural populations would have led us to expect. The reproductive performance of the population was investigated and intra and interwarren variations are analysed with respect to warren and group size. Results indicate an inverse relationship between warren size and reproductive success. The most frequently observed group composition (2 males, 2 females) was also the most reproductively successful. Daily and seasonal activity patterns of different age, sex and social status classes of rabbits are described. Olfactory communication was investigated by analysis of the frequency, daily and seasonal variation, and behavioural context of odour related activities performed by members of different age, sex and social status classes. The importance of using appropriate methods for the sampling of behaviour in field studies of olfaction is stressed. The present study concentrates on behaviour related to latrines; chin marking of the substrate and of conspecifics; enurination and urine squirting; and pawscraping. The results suggest that different scent products may carry similar information but analysis of variations in the frequency and context of odour deposition suggests that the deposition of scent fulfills a variety of functions.

The common ringtail possum (Pseudocheirus peregrinus), a member of the family Pseudocheiridae, is an arboreal folivorous marsupial that feeds predominantly on Eucalyptus foliage. Contrary to the expectation that small body size would inhibit utilisation of a diet containing such high levels of lignified fibre because of relatively low gut volume to body mass ratios and relatively high mass-specific metabolic rates and nutrient requirements (Hume 1999), the ringtail possum is able to survive solely on a diet of Eucalyptus foliage. The rabbit (Oryctolagus cuniculus) is a terrestrial herbivore and is a member of the family Leporidae that feeds predominantly on grasses. The rabbit was proposed as a digesta flow model for the ringtail possum since both are caecotrophic (periodically re-ingest caecal contents) and both are proposed to exhibit a colonic separation mechanism (CSM) where fluids and small, easily digested particles are preferentially returned to the caecum. The rabbit is of value for the modelling process since it is more accessible for experimental manipulation than the ringtail possum. This study investigated a proposal to use digesta passage through the gastrointestinal tract (GIT) of the rabbit as a model of digesta passage for the ringtail possum on the basis that both are caecotrophic caecum fermenters. A number of potential problems were identified with this proposal and investigation of these problems formed the basis for the research described in this thesis. Two main areas were identified as being potentially problematic: 1) fundamental flaws with the particulate markers used in digesta rate of passage studies; and 2) differences in animal behaviour and natural diet between the two subject species which suggested different digestive strategies and hence different patterns of digesta flow through the GIT. The proposed digesta passage markers were lanthanide metals (Dy, Tm, Eu and Yb) attached to either fibrous particles (1200 - 600�m) or formalin-fixed rumen bacteria (20 � 0.2�m). These markers were shown to not be of the assumed size classes and the extent of lanthanide metal binding differed between the four metals used. An effect due to method of dosing was also observed. The findings of marker inconsistencies caused major limitation to model development and further research is necessary to clarify these markers. The proposal to use digesta flow in the rabbit GIT as a model for digesta flow in the ringtail possum was shown to be idealistic due to the differences in anatomy and behaviour observed between the two herbivores. Laboratory observations, time series analysis and compartmental modelling confirmed the differences between the animals. This study showed: 1) the GIT of the rabbit was more complex both anatomically and functionally than that of the ringtail possum; 2) behaviour affecting digesta passage of the rabbit and ringtail were different and; 3) compartmental models confirmed the anatomical and behavioural findings. Digesta passage in the rabbit could not be modelled mathematically using data on digesta passage due to complexities of the system. In contrast, a basic model was constructed for digesta passage in the ringtail possum. On the basis of these findings, the research hypothesis "that digesta passage in rabbits is similar to that in ringtail possums" was rejected.

The common ringtail possum (Pseudocheirus peregrinus), a member of the family Pseudocheiridae, is an arboreal folivorous marsupial that feeds predominantly on Eucalyptus foliage. Contrary to the expectation that small body size would inhibit utilisation of a diet containing such high levels of lignified fibre because of relatively low gut volume to body mass ratios and relatively high mass-specific metabolic rates and nutrient requirements (Hume 1999), the ringtail possum is able to survive solely on a diet of Eucalyptus foliage. The rabbit (Oryctolagus cuniculus) is a terrestrial herbivore and is a member of the family Leporidae that feeds predominantly on grasses. The rabbit was proposed as a digesta flow model for the ringtail possum since both are caecotrophic (periodically re-ingest caecal contents) and both are proposed to exhibit a colonic separation mechanism (CSM) where fluids and small, easily digested particles are preferentially returned to the caecum. The rabbit is of value for the modelling process since it is more accessible for experimental manipulation than the ringtail possum. This study investigated a proposal to use digesta passage through the gastrointestinal tract (GIT) of the rabbit as a model of digesta passage for the ringtail possum on the basis that both are caecotrophic caecum fermenters. A number of potential problems were identified with this proposal and investigation of these problems formed the basis for the research described in this thesis. Two main areas were identified as being potentially problematic: 1) fundamental flaws with the particulate markers used in digesta rate of passage studies; and 2) differences in animal behaviour and natural diet between the two subject species which suggested different digestive strategies and hence different patterns of digesta flow through the GIT. The proposed digesta passage markers were lanthanide metals (Dy, Tm, Eu and Yb) attached to either fibrous particles (1200 - 600�m) or formalin-fixed rumen bacteria (20 � 0.2�m). These markers were shown to not be of the assumed size classes and the extent of lanthanide metal binding differed between the four metals used. An effect due to method of dosing was also observed. The findings of marker inconsistencies caused major limitation to model development and further research is necessary to clarify these markers. The proposal to use digesta flow in the rabbit GIT as a model for digesta flow in the ringtail possum was shown to be idealistic due to the differences in anatomy and behaviour observed between the two herbivores. Laboratory observations, time series analysis and compartmental modelling confirmed the differences between the animals. This study showed: 1) the GIT of the rabbit was more complex both anatomically and functionally than that of the ringtail possum; 2) behaviour affecting digesta passage of the rabbit and ringtail were different and; 3) compartmental models confirmed the anatomical and behavioural findings. Digesta passage in the rabbit could not be modelled mathematically using data on digesta passage due to complexities of the system. In contrast, a basic model was constructed for digesta passage in the ringtail possum. On the basis of these findings, the research hypothesis "that digesta passage in rabbits is similar to that in ringtail possums" was rejected.

El objetivo de esta tesis ha sido estudiar la respuesta directa a la selección por tasa de ovulación en conejo y las respuestas correlacionadas en tamaño de camada y tasas de supervivencia. Los animales pertenecían a una línea de conejos seleccionada por tasa de ovulación durante 10 generaciones. La selección se realizó en base al valor fenotípico de la hembra, que se midió el día 12 de la segunda gestación mediante laparoscopia. Se creó una línea control a partir de la recuperación de aproximadamente 470 embriones de 50 hembras donantes de la generación base. Los embriones fueron vitrificados y almacenados en nitrógeno líquido hasta su transferencia al final del experimento de selección (generación 10 de la línea seleccionada). Se midieron los siguientes caracteres: tamaño de camada (LS), estimada como el número total de gazapos al parto en un máximo de 5 partos; tasa de ovulación (OR), estimada como el número de cuerpos lúteos en los dos ovarios; tasa de ovulación derecha y tasa de ovulación izquierda (ROR y LOR); el número de embriones implantados totales (IE), en el lado derecho (RIE) y en el lado izquierdo (LIE); la diferencia ovulatoria (OD), definida como la diferencia entre ROR y LOR, expresada en valor absoluto; la diferencia de implantación (ID), definida como la diferencia entre RIE y LIE, expresada en valor absoluto; la supervivencia embrionaria (ES), calculada como IE/OR; la supervivencia fetal (FS), calculada como LS/IE; la supervivencia prenatal (PS), calculada como LS/OR. Se utilizó metodología bayesiana para analizar los datos. Las estimas de las heredabilidades de OR, LS, ES, FS y PS fueron 0.16, 0.09, 0.09, 0.24 y 0.14, respectivamente. Las estimas de las correlaciones fenotípicas de OR con LS, ES, FS y PS fueron 0.09, -0.07, -0.26 and -0.28, respectivamente. Las estimas de las correlaciones genéticas de OR con LS y ES tuvieron una baja precisión, y no se pudo concretar su signo. Las estimas de las correlaciones genéticas de OR con FS y PS fueron negativas (probabilidad de ser negativa de 1.00 y 0.98, respectivamente). Las correlaciones fenotípicas y genéticas entre LS y las tasas de supervivencias fueron positivas (probabilidad de ser positivas de 1.00).
Laborda Vidal, P. (2011). Selection for ovulation rate in rabbits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/14121
Palancia

The meniscus is essential for normal knee function. Previously considered unimportant, removal was performed when injured. This frequently led to degenerative arthritic changes. Today surgeons attempt to repair or minimally resect torn menisci, however many patients are encountered with irreparable tears or previously removed menisci. In these patients meniscale transplantation may prevent degenerative arthritis from developing.
Problems facing transplantation are ability to store tissues and prevent disease transmission. To overcome this, freezing and irradiation effects were examined on 60 rabbits undergoing medial meniscal transplantation. Fresh, frozen, and frozen-irradiated allografts were followed up to 17 months, 10 other rabbits underwent meniscectomy alone.
Zero-time studies revealed that freezing with or without irradiation rendered cells non-viable with no changes in mechanical properties. At long term follow-up, all grafts healed, and showed repopulation with metabolically active cells determined radioautographically. Mechanical properties were unchanged, except for a decreased time constant in the frozen group. Degenerative changes were not significantly different among groups.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Two experiments were conducted, the first to determine the chemical and digestible energy of dried brewers grain (DBG) and the second to evaluate the effect of the inclusion of this ingredient in the feeding of growing rabbits on performance, carcass characteristics, meat quality and economic viability. For the digestibility assay a total of 28 males rabbits were used, White New Zealand x California, with 50 days of age with an initial weight of 1.400Â0.100 kg, distributed on a completely randomized block design, with two treatments and fourteen replications, using the total of feces method. The treatments were: basal diet (BD) and ration test (RT) comprised 60% of basal diet and 40% dried brewers grain. The dried brewers grain showed 90.43% of dry matter, 37.94% of crude protein, 51.72% of neutral detergent fiber, 22.08% of acid detergent fiber, 8.06% of ether extract, 5.30% of mineral matters and 3371.24 kcal of digestible energy/kg. To test the performance, a total of eighty rabbits (40 males and 40 females), White New Zealand x California, in the period from 40 to 90 days of age, allocated in a completely randomized block design in a 5x2 factorial arrangement, considering five levels of inclusion of the DBG (0, 7, 14, 21 e 28%), and sex (male and female), with four replicates of two animals. No effects were observed on the performance, however, it was observed that the carcass weight decreased linearly, while the pÃncreas weight increased, due to the higher level of inclusion of the DBG. The weight of the liver of animals fed with DBG over 14% was lower than in animals that received feed without this ingredient. There was no effect of treatments on quality characteristics of meat rabbits. No effects were observed on relation meat/bone and qualitative meat characteristics. Considering the lower cost value of feed and better economic efficiency and cost indexes, the DBG may be included up to 28% in growing rabbits diets.
Foram realizados dois ensaios, sendo o primeiro para determinar a composiÃÃo quÃmica e a energia digestÃvel do resÃduo desidratado de cervejaria (RDC) e o segundo para avaliar o efeito da inclusÃo deste ingrediente na dieta de coelhos em crescimento sobre o desempenho, caracterÃsticas da carcaÃa, qualidade da carne e viabilidade econÃmica. Para o ensaio de digestibilidade foram utilizados 28 coelhos machos com 50 dias de idade e peso inicial de 1,400Â0,100 kg, distribuÃdos no delineamento em blocos ao acaso, com dois tratamentos e quatorze repetiÃÃes, utilizando mÃtodo de coleta total de fezes. Os tratamentos foram: raÃÃo referÃncia (RR) e raÃÃo teste (RT) composta por 60% da raÃÃo referÃncia e 40% de resÃduo desidratado de cervejaria. O resÃduo desidratado de cervejaria apresentou 90,43% de matÃria seca, 37,94% de proteÃna bruta, 51,72% de fibra em detergente neutro, 22,08% de fibra em detergente Ãcido, 8,06% de extrato etÃreo, 5,30% de matÃria mineral e 3371,24 kcal de energia digestÃvel/kg. Para o ensaio de desempenho foram utilizados 80 coellhos (40 machos e 40 fÃmeas) oriundos do cruzamento das raÃas Nova ZelÃndia Branco x CalifÃrnia, no perÃodo de 40 a 90 dias de idade, distribuÃdos no delineamento em blocos ao acaso em esquema fatorial 5x2, considerando cinco nÃveis de inclusÃo do RDC (0, 7, 14, 21 e 28%) e o sexo (macho e fÃmea), com quatro repetiÃÃes de dois animais. NÃo houve efeito dos tratamentos sobre o desempenho dos coelhos, no entanto, observou-se que o peso de carcaÃa decresceu linearmente enquanto o peso do pÃncreas aumentou, em funÃÃo do maior nÃvel de inclusÃo do RDC. O peso do fÃgado dos animais alimentados com raÃÃes contendo RDC acima de 14% foi menor em relaÃÃo aos animais que receberam raÃÃo sem este ingrediente. NÃo houve efeito dos tratamentos sobre a relaÃÃo carne/osso e caracterÃsticas qualitativas da carne avaliadas. Em funÃÃo do menor valor de custo com alimentaÃÃo bem como dos melhores Ãndices de eficiÃncia econÃmica e de custo, o RDC pode ser incluÃdo em atà 28% em raÃÃes para coelhos em crescimento.

Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains x, 100 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 91-96).

Thesis (Ph. D.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Vita. "December 2006" Includes bibliographical references.

The purpose of this study was to substantiate previous claims that differential growth across the frontonasal suture occurs and if this differential growth pattern is caused by an increased mitotic rate of the nasal bone. Two six week old New Zealand White Rabbits were given calcein 20mg/kg IA, demeclocycline 20mg/kg IA, and BrdU 40mg/kg IA on Days 1, 11, and 14, respectively. The animals were euthanized using Ketamine 31.6mg/kg IM and Pentobarbital 100mg/kg IV. The frontonasal suture was removed from the rabbit and divided into hemisections. The right hemisection was histologically processed using standard calcified methods which were modified and used for smaller bone sections at the Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin. The left hemisection was reserved for BrdU staining at the Central Microscopy Research Facility, University of Iowa. The resultant slides were imaged and photographed using an Olympus BX-40 microscope and measured using ImageJ software (NIH). Means and standard deviations were calculated for interlabel distance and mineral apposition rate (MAR). All frontonasal suture sites demonstrated double fluorochrome labeling. Samples F2-2 and M2-1 demonstrated the predicted differential growth pattern. Samples F2-1 and M2-2 did not. No suture sites demonstrated positive staining for BrdU. Although the sample size was small (n=2), this may demononstrate a trend toward differential growth of the suture. Due to the small sample size, the labeling protocol used in this study provided limited quantitative data. Although two sections did not demonstrate more bone deposition or faster mineral apposition rate of the nasal bone, it is important to consider that these sections were of poorer quality when compared to the other sections. Higher quality sections with clear, measurable margins showed a difference between frontal and nasal bone growth in both morphology and mineral apposition rate.

The mechanism of rabbit skeletal muscle phosphoglucomutase (EC.2.7.5.1) has been investigated using fluorinated and deoxygenated substrate analogues. Each of the analogues in which the non-acceptor hydroxyls are replaced by fluorine or hydrogen are substrates of the enzyme. The kinetic constants of these substrates are reported. The rate of the mutase reaction of each substrate analogue in the presence of glucose 1,6-diphosphate is the same as that of the half reaction involving production of the fluorinated and deoxygenated glucose 1,6-diphosphate species. The exceptions are 3-fluoro- and 3-deoxy-glucose 1-phosphate, in which cases the rates of the half reactions are 8 times that of the overall mutase reaction. The Km of 3-fluoro-glucose 1,6-diphosphate is approximately 90 times that of glucose 1,6-diphosphate and the other deoxy and fluoro analogues. The inhibition of phosphoglucomutase by fluorinated and deoxygenated substrate analogues has been investigated. The synthesis of a series of novel disubstituted inhibitors (based on glucose 1-phosphate) in which the C-6 hydroxyl is replaced by fluorine and a sugar ring hydroxyl is replaced by either hydrogen or fluorine is described. The inhibition constants show that the hydroxyl distal to the acceptor hydroxyl is most important in the formation of a strong enzyme-inhibitor complex. The synthesis is described of three phosphorofluoridate analogues of glucose phosphate substrates. These analogues were found to only weakly inhibit phosphoglucomutase. No evidence of any phosphoryl transfer between the phosphoenzyme and the phosphorofluoridate analogues could be detected. Thus phosphoglucomutase has a strict requirement for a doubly negatively charged substrate phosphate group. The interaction of phosphoglucomutase with fluorinated substrates and inhibitors has been investigated by ¹⁹Fnmr. Large downfield changes in the chemical shifts of the inhibitors 6-fluoro-glucose 1-phosphate and α-glucosyl fluoride 6-phosphate were found to accompany binding to the phosphoenzyme. The effects of the binding of activating and non-activating metal ions on these spectra were investigated. The different effects observed may be directly related to the chemical basis for the metal induced activation of the enzyme. ¹⁹Fnmr data consistent with a 10² to 10³ fold increase in the tenacity with which phosphoglucomutase binds substrates and inhibitors in the presence of Li⁺ were observed in the spectra of the phosphoenzyme with difluorinated glucose 1-phosphate inhibitors. Two enzyme bound species were detected in the ¹⁹Fnmr spectra of the complexes formed by reaction of the Cd²+ phosphoenzyme with 2- and 3-fluoro-glucose phosphates. These species are tentatively assigned as the fluoro-glucose 1,6-diphosphate species bound in two different modes to the dephosphoenzyme. Only one bound species was observed in the case of 4-fluoro-glucose phosphates. The environment of each substrate glucose hydroxyl in the active site was probed using ¹⁹Fnmr and the fluorinated glucose phosphate substrates. Data inconsistent with a minimal motion type of mechanism (W.J. Ray, A.S. Mildvan & J.W. Long, Biochemistry 1973,12, 3124) were obtained. The results of the nmr and kinetic studies are consistent with an exchange type of mechanism in which the C-3 hydroxyl plays an important role in the reorientation of the glucose 1,6-diphosphate. The data also suggest that there are two distinct glucose binding sites, one for each substrate and glucose 1,6-diphosphate bound in the same mode.
Science, Faculty of
Chemistry, Department of
Graduate

[ES] Cualquier mejora en el conocimiento de la nutrición y el manejo de los futuros conejos reproductores debe considerarse como prioritario en la producción cunícola. Sin embargo, los principales esfuerzos en investigación se han centrado en estos animales durante la fase de reproducción propiamente dicha. La hipótesis inicial de esta tesis fue que alcanzar un desarrollo temprano adecuado durante la gestación, lactancia, engorde y recría, con la ayuda de programas ajustados de alimentación en algunos de estos períodos, mejoraría el rendimiento reproductivo y la vida útil de los futuros conejos reproductores. Para evaluar esta hipótesis, se llevaron a cabo dos tipos de ensayos, tanto en conejos hembra de líneas maternas como en machos de líneas seleccionadas por velocidad de crecimiento y destinadas a la inseminación artificial. El primero de estos ensayos se centró en los diferentes patrones de crecimiento, desde el nacimiento hasta el final de la fase de recría, y su influencia en la carrera reproductiva y la vida útil del conejo. En el segundo tipo de pruebas, se evaluó el efecto del uso de diferentes dietas o programas de alimentación durante el período de recría en la productividad a corto y medio plazo. Los resultados muestran dos fases importantes en el desarrollo temprano, de acuerdo con sus efectos sobre el rendimiento reproductivo y la vida útil. Mostrar un mayor desarrollo corporal desde el nacimiento hasta los 63 días de vida parece tener una influencia positiva en el grado de madurez y la productividad al comienzo de su vida reproductiva, además de poder mejorar su supervivencia a corto plazo, pero con posibles efectos negativos en la esperanza de vida a largo plazo. Sin embargo, el desarrollo durante el período de recría (desde los 63 días de vida hasta el comienzo de la carrera reproductiva) parece tener un mayor impacto en la productividad y la esperanza de vida de nuestros futuros conejos reproductores. Las hembras más engrasadas en la primera inseminación tuvieron tamaños de camada más pequeños y un mayor riesgo de ser sacrificadas que las magras (P<0.05). Además, los machos que mostraron una mayor ganancia media diaria durante el período de recría tuvieron un número y porcentaje de eyaculados viables más bajos a lo largo de su vida productiva y mayor riesgo de muerte o sacrificio. Estos resultados podrían indicar que la clave para llevar a cabo un desarrollo adecuado durante el período de recría debería basarse tanto en conseguir que los conejos alcancen un grado de madurez apropiado, tanto fisiológica como reproductivamente, así como evitar un excesivo engrasamiento al inicio de su vida productiva. En los ensayos destinados a evaluar los programas de alimentación durante la recría, el uso de una restricción alimentaria en hembras, y especialmente el uso de dietas fibrosas (de 8.5 a 10 MJ ED/kg MS) permiten un desarrollo corporal gradual y adecuado a la edad de cubrición, con suficientes reservas corporales para afrontar el comienzo de la vida reproductiva y mejorando tanto su rendimiento reproductivo como su vida útil. El éxito de estos programas de alimentación de recría depende del momento y la duración de la aplicación de estos, mejorándose con la aplicación de un cambio a un pienso enriquecido energéticamente alrededor del primer apareamiento. En los machos, se observó que un programa de alimentación durante la recría adecuado debería adaptarse a la capacidad de ingesta de estos y a sus necesidades nutricionales en períodos concretos de la recría, consiguiendo así mejoras en algunos parámetros del semen al inicio de su vida reproductiva. En conclusión, tanto un desarrollo temprano adecuado desde la gestación hasta el comienzo de su vida reproductiva, como el uso de programas adecuados de alimentación durante la recría podrían mejorar significativamente el rendimiento reproductivo futuro, así como la esperanza de vida, tanto en conejos he
[CAT] Qualsevol millora en el coneixement tant de la nutrició com del maneig dels futurs conills de criança ha de considerar-se com a prioritari en la producció de conills. No obstant açò, els principals esforços en investigació s'han centrat en aquests animals durant la fase de reproducció pròpiament dita. La hipòtesi inicial d'aquesta tesi va ser que aconseguir un desenvolupament primerenc adequat durant la gestació, lactància, engreix i criança, amb l'ajuda de programes ajustats d'alimentació en alguns d'aquests períodes, milloraria el rendiment reproductiu i la vida útil dels futurs conills reproductors. Per a avaluar aquesta hipòtesi, es van dur a terme dos tipus d'assajos, tant en conills femella de línies maternes, com en mascles de línies seleccionades per a la velocitat de creixement i destinades a la inseminació artificial. El primer d'aquests assajos es va centrar en els diferents patrons de creixement, des del naixement fins al final de la fase de criança, i la seua influència en la carrera reproductiva i la vida útil del conill. En el segon tipus de proves, es va avaluar l'efecte de l'ús de diferents dietes o programes d'alimentació durant el període de criança, en la productivitat a curt i mig termini. Els resultats obtinguts semblen indicar que podríem diferenciar dues fases en el desenvolupament primerenc, d'acord amb els seus efectes sobre el rendiment reproductiu i la vida útil. Mostrar un major desenvolupament corporal des del naixement fins als 63 dies de vida sembla tenir una influència positiva en el grau de maduresa i la productivitat al començament de la seua vida reproductiva, a més de poder millorar la seua supervivència a curt termini, però amb possibles efectes negatius en l'esperança de vida a llarg termini. No obstant açò, el desenvolupament durant el període de sembla tenir un major impacte en la productivitat i l'esperança de vida dels nostres futurs conills reproductors. Les femelles més greixades en la primera inseminació van tenir grandàries de ventrada més xicotets (tant nascuts com deslletats) i un major risc de ser sacrificades que les magres (P<0.05). A més, els mascles que van mostrar un major guany mitjà diari durant el període de criança van tenir un nombre i percentatge d'ejaculats viables més baixos al llarg de la seua vida productiva i major risc de mort o sacrifici. Aquests resultats podrien indicar que la clau per a dur a terme un desenvolupament adequat durant el període de criança hauria de basar-se tant a aconseguir que els conills aconseguisquen un grau de maduresa apropiat, per a afrontar els futurs desafiaments productius, com evitar un excessiu greixatge a l'inici de la seua vida productiva. En els assajos destinats a avaluar els programes d'alimentació durant la criança, l'ús d'una restricció alimentària en femelles, i especialment l'ús de dietes fibroses (de 8.5 a 10 MJ ED/kg MS) permeten un desenvolupament corporal gradual i adequat a l'edat de cobriment, amb suficients reserves corporals per a afrontar el començament de la vida reproductiva i millorant tant el seu rendiment reproductiu com la seua vida útil. L'èxit d'aquests programes d'alimentació de criança depèn del moment i la durada de l'aplicació d'aquests, millorant-se amb l'aplicació d'un canvi a un pinso enriquit energèticament al voltant del primer cobriment. En els mascles, es va observar que un programa d'alimentació durant la criança adequat hauria d'adaptar-se a la capacitat d'ingesta d'aquests i a les seues necessitats nutricionals en períodes concrets de la criança, aconseguint així millores en alguns paràmetres del semen a l'inici de la seua vida reproductiva. En conclusió, tant un desenvolupament primerenc adequat des de la gestació fins al començament de la seua vida reproductiva, com l'ús de programes adequats d'alimentació durant la criança podrien millorar significativament el rendiment reproductiu futur, així com l'esperança
[EN] Any improvement on the knowledge of both nutrition and management of the future rabbit breeders should be considered as crucial. However, main research efforts have been focused on animals during reproduction phase. The initial hypothesis of this thesis was that achieving an adequate early development during young rabbits' gestation, lactation, fattening and rearing, with the help of fitted feeding programmes in some of these periods, would be improved reproductive performance and lifespan of the future breeding rabbits. To evaluate this hypothesis, two types of trials, both in rabbit females from maternal lines selected for litter size at weaning and males from paternal lines selected for growth rate and intended on artificial insemination, were carried out. The first of these trials were mainly focused on the different growth patterns, from birth to the end of the rearing age, and their influence on rabbit's reproductive career and lifespan. In a second type of trials, the effect of the use of different diets or feeding programs during the rearing period in the performance in the short- medium-term was evaluated. The results obtained from the evaluation of the different growth patterns trials seem to indicate that, we could differentiate two parts on the early development according to their effects on reproductive performance and lifespan. To show a greater body development from birth to 63 days of life seems to have a positive influence on the maturity degree and productivity at the beginning of their reproductive life, as well as being able to improve their survival in the short-term, but it could be even negative for long-term lifespan. However, the development during the rearing period (from 63 days of life to the beginning of reproduction career) seems to have a higher impact on the productivity and lifespan of our rabbit breeders. Fatter rabbit females at first insemination had smaller litter sizes (born and weaned) and a higher risk of being culled (+13% per positive change in mm of perirenal fat) than lean ones (P<0.05). Also, rabbit males that showed a greater average daily gain during rearing period had a lower number and percentage of profitable ejaculates through it productive life (-10.1 and -4.9% per each 10 g of daily gain increase, respectively; P<0.05) and higher risk of death or culling (+16.2% per each increase in one standard deviation unit on live weight; P<0.05). These results could indicate that the key to carrying out an adequate development during the rearing period should allow the rabbits to reach an appropriate degree of physiological and reproductive maturity to face the future productive challenges, avoiding an excessive fatness at the beginning of their productive life. The use of a feeding restriction in rabbit females, and especially the use of fibrous diets (from 8.5 to 10 MJ DE/ kg DM) lead a gradual and adequate body development at mating, with enough body reserves to face the beginning of reproduction life and improving their whole reproductive performance and lifespan. The success of these rearing feeding programs depends in the moment and duration of application of them and improved with the application of a nutritional flushing around first mating. In rabbit males, it was observed that an adequate rearing feeding program should adapt it to the male's intake capacity and their nutritional requirements rearing period, especially to their high DP needs at the beginning of rearing period or when their requirements were close to maintenance, to improve some semen parameters at the beginning of their reproduction life. In conclusion, both the adequate early development of future rabbit breeders, from their own gestation to the beginning of their reproductive life, and the use of appropriate rearing feeding programs could significantly improve their future reproductive performance, as well as their life expectancy, both in rabbit females and males.
Martínez Paredes, EM. (2019). Rearing programmes for breeding rabbits. Effect of early development and feeding on future reproductive performance of rabbit females and males [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124969
TESIS

Ventilation by high-frequency body-surface oscillation (HFBSO) was studied in normal rabbits. Adequate ventilation and acceptable gas exchange took place during HFBSO from 3 to 15 Hz. The tidal volume required to maintain a normocapnic state was established at each frequency studied. Using catheter-tip micromanometers inserted in the esophagus or the superior vena cava, new techniques to measure high-frequency intrathoracic pressure oscillations were developed. Using a gamma-function to fit the thermodilution curve, a new technique was developed to measure the cardiac output in small animals. No detrimental hemodynamic effect was found during HFBSO used either for normocapnic ventilation or with large pressure oscillations (30 cm H$ sb{ rm 2}$O) in the body chamber. Finally, during normocapnic ventilation by HFBSO in normal rabbits, the mechanical behavior of the respiratory system was characterized using transfer impedances.

[EN] The global objective of the present thesis was to study the functional longevity defined as length of productive life (LPL) in five Spanish specialized lines of rabbit (A, V, H and LP). Chapter 3, aimed to check the genetic heterogeneity for longevity between the five lines estimating the additive variance and the corresponding effective heritabilities. As well as to test the genetic importance of time-dependent factors such as positive palpation order (OPP), physiological status (PS) and number of kits born alive (NBA) on the genetics of longevity. This point has been assessed using four different Cox proportional hazard models; the first one (Model 1) included all the previous factors in addition to the year-season effect, the inbreeding coefficient effect and finally the animal effect as random factor. The remaining three models were the same as Model 1 but excluding OPP (Model 2), or PS (Model 3), or NBA (Model 4). The complete data set comprised 15,670 does with records 35.6 % having censoring data, and the full pedigree file involved 19,405 animals. The heritability estimates for longevity in the five lines were low and ranged from 0.02±0.01 to 0.14±0.09, and consequently, it is not recommended to include this trait as selection criteria in rabbit breeding programs. Despite of the large variation of the heritability estimates, the corresponding HPD95% always overlapped and consequently the hypothesis of all lines having the same heritability cannot be discarded. Comparing the additive variance estimates of the four models, it was observed that by correcting for PS 51, 39, 38, 83 and 75% of the additive variance in lines A, V, H, LP and R, respectively, was removed. The risk of death or culling decreases as OPP advanced. Non-pregnant-non-lactating females are those under the higher risk. The does which had zero NBA had the highest risk, apart for this special figure (zero NBA) the risk decreased as NBA increased. Chapter 4 intended to estimate the genetic and environmental correlations between longevity and two prolificacy traits (number of kits born alive (NBA) and number of kits alive at weaning (NW)). Furthermore, to estimate the genetic and environmental correlations between longevity and the percentage of days that the doe spent in the different physiological statuses with respect to its entire productive life. The complete pedigree file comprised 19,405 animals. The datasets included records on 15,670 does which had 58,329 kindlings and 57,927 weanings. In general the genetic correlations between NBA and NW, and the hazard were low to very low, and the only line for which it can be said these genetic correlation to be different from zero was the LP line. Regarding the correlations between longevity and the percentage of days the doe spent in each physiological status, there were evidences of non-negligible genetic correlations between the two traits. Chapter 5 purposed to compare the five lines at their foundation and at fixed time periods during their selection programs. The first comparison was done at the origin of the lines, involving the complete data set, and using a genetic model (CM) including the additive values of the animals, so the effect of selection was considered. For the second comparison the same model as the first comparison was used, but excluding the additive effects from the model of analysis (IM), and involving only the data corresponding to each period, so the differences between the lines included the additive values of the animals. The lines V, H and LP showed at foundation a substantial superiority over line A. The line R had higher risk of death or culling with relevant differences when compared to V, H and LP lines. The maximum relative risks were observed between the lines LP and R (0.239), and between LP and A (0.317). For the comparisons at fixed times, the pattern of the differences between the A line and the others was similar to those observed at foundation.
[ES] El objetivo global de la presente tesis fue estudiar la longevidad funcional en cinco líneas españolas de conejos (A, V, H y LP), el carácter se definió como la longitud de la vida productiva. En el Capítulo 3, dirigido a comprobar la heterogeneidad genética de la longevidad entre las 5 líneas, se estimaron las varianzas aditivas y sus correspondientes heredabilidades efectivas. Y además se evaluó la importancia del orden de la palpación positiva (OPP), el estado fisiológico (PS) y el número de gazapos nacidos vivos (NBA) sobre el determinismo genético de la longevidad. Para ello se utilizaron 4 modelos de Cox de riesgos proporcionales; el primer modelo (Modelo 1) incluyó todos los factores anteriores, además del efecto del año-estación, el efecto de la consanguinidad y, finalmente, el valor aditivo de los animales como efecto aleatorio. Los otros tres modelos fueron igual que el Modelo 1 pero excluyendo OPP (Modelo 2), o PS (Modelo 3), o NBA (Modelo 4). Los datos de longevidad estaban referidos a 15,670 conejas y tuvieron una tasa de censura de 35.6%. La genealogía completa involucró a 19,405 animales. Las estimas de heredabilidad efectiva para la longevidad en las 5 líneas fueron bajas y variaron de 0.02±0.01 a 0.14±0.09. A pesar de la gran variación de las estimas puntuales de heredabilidad, los correspondientes intervalos HPD95% siempre se solaparon y por lo tanto la hipótesis de que todas las líneas tengan la misma heredabilidad no pudo descartase. Se observó que la exclusión de PS incrementó la varianza aditiva aproximadamente, en un 51, 39, 38, 83 y 75% en las líneas A, V, H, LP y R, respectivamente. El riesgo de muerte o eliminación disminuía a medida que avanzaba el OPP, observándose el riesgo más alto durante los primeros dos partos, partos en los que las conejas todavía están creciendo lo que sería un factor de riesgo importante. El nivel No-Gestante-No-Lactante de PS tuvo el mayor riesgo. Este nivel se interpreta como indicador de baja fertilidad y/o problemas de salud de la coneja. Las conejas que tenían cero NBA tuvieron el mayor riesgo de muerte o eliminación, aunque para el resto de niveles de NBA se apreció una disminución del riesgo a medida que aumenta la prolificidad. En el capítulo 4, se estimaron las correlaciones genéticas y ambientales entre la longevidad y dos caracteres de prolificidad [número de gazapos nacidos vivos (NBA) y el número de destetados (NW)]. El fichero de datos incluyó 58,329 partos y 57,927 destetes. También se estimaron las correlaciones entre longevidad y el porcentaje de días que la coneja pasó en los diferentes estados fisiológicos con respecto a la totalidad de su vida productiva. La única línea para la que se puede decir que la correlación genética entre NBA o NW y el riesgo fue significativamente diferente de cero fue la línea LP. Hubo evidencias de correlaciones genéticas no despreciables entre la longevidad y el porcentaje de días que la hembra pasó en cada estado fisiológico los dos caracteres. En el capítulo 5 se compararon las longevidades medias de las 5 líneas en su fundación y en períodos de tiempo determinados. La comparación de las líneas en el origen, utilizó todos los datos y un modelo genético (CM) que incluía los valores aditivos de los animales. Para la comparación en tiempos fijos se utilizó el mismo modelo, pero excluyendo los efectos aditivos del modelo de análisis (IM), utilizando sólo los datos correspondientes a cada período, por lo que las diferencias entre las líneas incluían los cambios debidos a la selección. Las líneas V, H y LP mostraron una superioridad sustancial sobre las líneas A y R. Los riesgos relativos máximos se observaron entre las líneas LP y R (0.239), y entre LP y A (0.317). Con respecto a las comparaciones en tiempos fijos, el patrón de las diferencias entre la línea de A y las otras líneas fue similar a los observados en la fundación.
[CAT] L'objectiu global de la present tesi va ser estudiar la longevitat funcional en cinc línies espanyoles de conills (A, V, H i LP), el caràcter es va definir com la longitud de la vida productiva. Al Capítol 3, dirigit a comprovar l'heterogeneïtat genètica de la longevitat entre les 5 línies, es van estimar les variàncies additives i les seues corresponents heretabilitats efectives. A més a més, es va avaluar la importància de factors dependents del temps, com l'orde de la palpació positiva (OPP) , l'estat fisiològic (PS) i el nombre de llorigons nascuts vius (NBA) sobre el determinisme genètic de la longevitat. Per a això es van utilitzar 4 models de Cox de riscos proporcionals; el primer model (Model 1) va incloure tots els factors anteriorment assenyalats, a més de l'efecte de l'any-estació, l'efecte de la consanguinitat i, finalment, el valor additiu dels animals com a efecte aleatori. Els altres tres models van ser igual que el Model 1 però excloent l'OPP (Model 2) , o PS (Model 3) , o NBA (Model 4) . Les dades de longevitat estaven referides a 15,670 conilles i van tindre una taxa de censura de 35.6%. La genealogia completa va involucrar a 19,405 animals. Les estimes d'heretabilitat efectiva (Model 1) per a la longevitat en les 5 línies van ser baixes i van variar de 0.02±0.01 a 0.14±0.09. A pesar de la gran variació de les estimes puntuals d'heretabilitat, els corresponents intervals HPD95% sempre es van solapar i per tant la hipòtesi que totes les línies tinguen la mateixa heretabilitat no va poder descartar-se. Es va observar que l'exclusió de PS va incrementar la variància additiva, aproximadament, en un 51, 39, 38, 83 i 75% en les línies A, V, H, LP i R, respectivament. El risc de mort o eliminació disminuïa a mesura que avançava l'OPP, observant-se el risc més alt durant els primers dos parts, en què les conilles encara estan creixent el que seria un factor de risc important. El nivell No-Gestant-No-Lactant de PS va tindre el major risc en comparació amb els altres nivells. Les conilles que tenien zero NBA van tindre el major risc de mort o eliminació, encara que per a la resta de nivells de NBA es va apreciar una disminució del risc a mesura que augmentà la prolificitat. Al Capítol 4, es van estimar les correlacions genètiques i ambientals entre la longevitat i dos caràcters de prolificitat [nombre de llorigons nascuts vius (NBA) i el nombre de deslletats (NW)]. El fitxer de dades va incloure 58,329 parts i 57,927 deslletaments. L'única línia per a la que es pot dir que la correlació genètica entre NBA o NW i el risc va ser significativament diferent de zero va ser la línia LP. Evidències de correlacions genètiques no menyspreables entre longevitat i els percentatge de dies que la femella va passar en cada estat fisiològic. Al Capítol 5 es compararen les longevitats mitges de les 5 línies en la seua fundació i en períodes de temps determinats. Per a la comparació de les línies a l'origen, es van utilitzar totes les dades i un model genètic (CM) que incloïa els valors additius dels animals, per la qual cosa es va considerar l'efecte de la selecció a partir de la fundació. En la comparació en temps fixos se va utilitzar el mateix model que en l'anterior, però excloent els efectes additius del model d'anàlisi (IM), utilitzant només les dades corresponents a cada període, per la qual cosa les diferències entre les línies incloïen els canvis deguts a la selecció. Les línies V, H i LP van mostrar una superioritat substancial sobre les línies A i R. Els riscos relatius màxims es van observar entre les línies LP i R (0.239), i entre LP i A (0.317). Respecte a les comparacions en temps fixos, el patró de les diferències entre la línia de A i les altres línies va ser semblant als observats en la fundació.
El Nagar, AGF. (2015). Genetic analysis of longevity in specialized lines of rabbits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/52390
TESIS

[EN] The aim of this thesis was to evaluate the productive performance of a rabbit line (OR-LS) selected by ovulation rate during first 6 generations (period 1), and later by ovulation rate (OR) and litter size (LS) during 11 generations using independent culling levels (Period 2). Genetic parameters, direct response for OR and LS and the correlated response for embryo (ES), foetal (FS) and prenatal survival (PS) were estimated. Also, the correlated response on growth rates (GR), weaning (WW) and marketing weight (MW) were estimated. The objective of chapter 3 was to estimate the genetic parameters of the productive traits and the response to selection by OR and LS of OR-LS line. For traits analysis, Bayesian methods were used. Heritability values of litter size traits were low, 0.10, 0.07, 0.07 and 0.07 for litter size, number of born alive (NBA), number of kits at weaning (NW) and marketing (NM), respectively. Heritability for OR was moderate (0.25), while it was low (0.13 and 0.14) for number of implanted embryos (IE) and number of live foetuses at 12 days of gestation (LF12), respectively. Low heritability values for survival traits were found, 0.09 for embryo survival (ES), 0.16 for foetal survival (FS) and 0.14 for prenatal survival (PS). In the second period, after 11 generations of selection by OR and LS, a genetic response of 0.17 kits per generation for LS was achieved. This response was higher than the obtained in period 1 (0.07 kits per generation), in which just selection by OR was performed. The opposite effect was found for OR; the highest response for OR appeared in the first period (0.24 ova per generation) versus the second period (0.17 ova per generation). This reduction in OR response can be due to the decrease in selection differential during the second period of selection. Since high genetic correlations were obtained for LS and other litter size traits, a positive correlated response was observed for NBA, NW and NM (0.12, 0.12 and 0.11 kits per generation, respectively) in the second period. In the first period, no correlated response on ES was observed and a decrease in FS (-0.04) was found. Nevertheless, in the second period a correlated response on PS appeared due to an improvement in both ES (0.04) and FS (0.03). Summarizing, the improvement in litter size in the second period is due to an increase in ovulation rate as well as an increase in prenatal survival. The objective of chapter 4 was to study the correlated response on growth traits in the OR-LS line in both periods of selection, the selection by OR during six generations and the selection by independent levels by OR and LS during 11 generations. The heritability estimates were low for weaning weight (WW), marketing weight (MW) and growth rate (GR), 0.09, 0.13 and 0.14, respectively. The estimated genetic correlations of WW, GR and MW with LS were around zero and with OR were positive and from low (0.19) to moderate (0.38). The positive moderate genetic correlation estimated between OR and MW could explain the correlated response found in MW. Correlated response on WW could be explained by positive and high genetic correlation between MW and WW. The aim of chapter 5 was to investigate magnitude and timing of embryo and early foetal survival in females with high OR using hormonal treatment as a model for selection by OR. Two groups of females (treated and untreated) were used. Treated females were injected with 50 IU eCG 48 hours before mating. Females were slaughtered at day 18 of gestation. OR, IE, LF12 and LF18 were recorded. Besides, ES (IE/OR), FSLF18 (LF18/IE), FSLF18/LF12 (LF18/LF12) and PSLF18 (LF18/OR) were estimated. Treated females had a higher OR than untreated females. According to the previous results for OR and LF18, treated females showed a lower survival rate from ovulation to 18 d of gestation. Treated females also had lower embryo and foetal survival. Main difference in foetal survival appeared from day 12 to 18 of gestation.
[ES] El objetivo de esta tesis fue evaluar el tamaño de camada de una línea de conejo seleccionada por tasa de ovulación durante las primeras seis generaciones (periodo 1) y después por tasa de ovulación (OR) y tamaño de camada (LS) durante 11 generaciones mediante el método de niveles independientes (periodo 2). Se estimaron los parámetros genéticos, así como la respuesta en OR y LS y la respuesta correlacionada en los caracteres reproductivos (capítulo 3). Además, se evaluó la respuesta correlacionada en los caracteres de crecimiento (capítulo 4); peso al destete (WW), peso al sacrificio (MW) y ganancia de peso entre el destete y el sacrificio (GR). Para el análisis de los caracteres se utilizaron métodos bayesianos. El objetivo del capítulo 3 fue estimar los parámetros genéticos de los caracteres reproductivos y la respuesta a la selección. Los valores de heredabilidad de los caracteres del tamaño de camada fueron bajos (alrededor de 0.10). La heredabilidad estimada para OR fue moderada (0.25), mientras que fue baja para el número de embriones implantados (IE) y el número de fetos vivos a los 12 días de gestación (LF12). Se obtuvieron valores bajos de heredabilidad; 0.09 para la supervivencia embrionaria (ES), 0.16 para la supervivencia fetal (FS) y 0.14 para la supervivencia prenatal (PS). En el periodo 2, se obtuvo una respuesta genética de 0.17 gazapos por generación para LS. Esta respuesta fue mayor que la obtenida en el periodo 1. En el caso de la tasa de ovulación, la mayor respuesta en OR se obtuvo en el periodo 1 (0.24 óvulos por generación) versus (0.17 óvulos por generación) en el periodo 2. Esta reducción en la respuesta de OR se puede atribuir a la disminución del diferencial de selección durante el período 2 de selección. De acuerdo con la alta correlación genética entre LS y otros caracteres del tamaño de camada, también se observó una respuesta correlacionada positiva en el número de nacidos vivos (NBA), destetados (NW) y comercializados (NM); 0.12, 0.12 y 0.11 gazapos por generación, respectivamente, en el segundo periodo. En el primer periodo no se observa respuesta correlacionada en la SE y se produce una disminución de la SF (-0.04). Sin embargo, en el segundo periodo se produce una respuesta correlacionada positiva en la SP que se debe a una mejora de la SE (0.04) y SF (0.03). En resumen, la mejora del tamaño de camada en el segundo periodo se debe tanto a un aumento de la tasa de ovulación como a un aumento de la supervivencia prenatal. El objetivo del capítulo 4 fue estudiar la respuesta correlacionada en los caracteres de crecimiento en esta línea. Las estimas de heredabilidad fueron bajas para los caracteres WW (0.09), MW (0.13) y GR (0.14). Las correlaciones genéticas estimadas de LS con WW, MW y GR fueron cercanas a cero; con la tasa de ovulación, las correlaciones fueron positivas y variaban de bajas a moderadas (de 0.19 a 0.38). La correlación genética moderada entre OR y MW podría explicar la respuesta correlacionada observada en MW. La alta correlación entre MW y WW podría explicar la respuesta correlacionada obtenida para WW. Finalmente, el objetivo de capítulo 5 fue estudiar en hembras con alta tasa de ovulación en qué momento se producen las mayores pérdidas fetales y cómo se ve afectado el desarrollo fetal. Para ello, de un total de 51 hembras, 24 hembras fueron pinchadas con 50 UI de eCG 48 horas antes de la cubrición para aumentar la tasa de ovulación. Las hembras fueron sacrificadas a los 18 días de gestación. Se registró OR, IE y el número de fetos vivos a los 12 y 18 días de gestación (LF18). Las hembras tratadas tuvieron una tasa de ovulación mayor que las no tratadas. De acuerdo con los resultados obtenidos para OR y LF18, las hembras tratadas mostraron una supervivencia más baja desde la ovulación hasta los 18 días de gestación y tuvieron una menor supervivencia embrionaria y fetal. Las principales diferencias en l
[CAT] L'objectiu d'esta tesi va ser avaluar la millora de la grandària de ventrada d'una línia de conill seleccionada per tasa d'ovulació durant les primeres sis generacions (període 1) i després per tasa d'ovulació (OR) i la grandària de ventrada (LS) durant 11 generacions per mitjà del mètode de nivells independents (període 2). Es van estimar els paràmetres genètics, així com la resposta en OR i LS i la resposta correlacionada en caràcters reproductius (capítol 3). A més, es va estudiar la resposta correlacionada en els caràcters de creixement (capítol 4); pes al deslletament (WW), pes al sacrifici (MW) i guany de pes entre el deslletament y el sacrifici (GR). Per a l'anàlisi dels caràcters es van utilitzar mètodes bayesians. L'objectiu del capítol 3 va ser estimar els paràmetres genètics dels caràcters reproductius i la resposta a la selecció. Els valors d'heretabilitat dels caràcters de la grandària de ventrada van ser baixos (al voltant de 0.10). L'heretabilitat estimada per a OR va ser moderada (0.25), mentres que va ser baixa per al nombre d'embrions implantats (IE) i el nombre de fetus vius als 12 dies de gestació (LF12). Es van obtindre valors baixos d'heretabilitat; 0.09 per a ES, 0.16 per a FS i 0.14 per a PS. En el període 2, es va obtindre una resposta genètica de 0.17 llorigons per generació per a LS. Esta resposta va ser major que l'obtinguda en el període 1. En el cas de la tasa d'ovulació, la major resposta per a OR va ser en el primer període (0.24 òvuls per generació) versus (0.17 òvuls per generació) en el període 2. Esta reducció en la resposta d'OR es pot atribuir a la disminució del diferencial de selecció durant el període 2 de selecció. Donada l'alta correlació genètica entre LS i altres caràcters de la grandària de ventrada, també es va observar una resposta correlacionada positiva en el nombre de nascuts vius (NBA), deslletats (NW) i comercialitzats (NM); 0.12, 0.12 i 0.11 llorigons per generació, respectivament, en el segon període. En el primer període no s'observa resposta correlacionada en la SE i es produeix una disminució de la SF (-0.04). No obstant això, en el segon període es produeix una resposta correlacionada en la SP que es deu a una millora de la SE (0.04) i SF (0.03). En resum, la millora de la grandària de ventrada en el segon període es deu tant a un augment de la tasa d'ovulació com a un augment de la supervivència prenatal. L'objectiu del capítol 4 va ser estudiar la resposta correlacionada en els caràcters de creixement en aquesta línia. Les estimes d'heretabilitat van ser baixes per als caràcters WW (0.09), MW (0.13) i GR (0.14). Les correlacions genètiques estimades de LS amb WW, MW i GR van ser pròximes a zero; amb la tasa d'ovulació, les correlacions van ser positives i variaven de baixes a moderades (de 0.19 a 0.38). La correlació genètica moderada entre OR i MW podria explicar la resposta correlacionada trobada per a MW. D'altra banda, l'alta correlació entre MW i WW podria explicar la resposta correlacionada obtinguda per a WW. Finalment. l'objectiu del capítol 5 va ser estudiar en femelles amb alta tasa d'ovulació en quin moment es van produir les majors pèrdues fetals i com es veu afectat el desenvolupament fetal. Per a això, d'un total de 51 femelles, 24 femelles van ser punxades amb 50 UI d'eCG 48 hores abans del cobriment per a augmentar la tasa d'ovulació. Les femelles van ser sacrificades al 18 dies de gestació. Es va registrar OR, IE i el nombre de fetus vius al 12 i 18 dies de gestació (LF18). Les femelles tractades van tindre una tasa d'ovulació major que les no tractades. D¿acord als resultats obtinguts per OR i LF18, les femelles tractades van mostrar una supervivència més baixa des de l'ovulació fins als 18 dies de gestació i van tindre una menor supervivència embrionària i fetal. Les principals diferències en la supervivència fetal van aparèixer entre els dies 12 i 18 de gestaci
Yehia Badawy Elmoghazy, A. (2016). SELECTION FOR OVULATION RATE AND LITTER SIZE IN RABBITS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/73265
TESIS

Thesis (Ing. Agropecuario)--Universidad Técnica del Norte, Facultad de Ingeniería en Ciencias Agropecuarias y Ambientales, Escuela de Ingeniería Agropecuaria, 2006.
Reproduced from copy at BYU's Benson Institute. Includes bibliographical references (leaves 75-76).

An effective vaccine against chancroid could take the place of therapeutic control programs, offering long-lasting protection without the risk of widespread drug resistance. Orally administered recombinant attenuated Salmonella strains are used as vaccine vectors to deliver heterologous, pathogen-derived antigens to intestinal mucosal associated lymphoid tissue, and to provide vaccine adjuvancy. Chancroid vaccines are tested in a temperature-dependent rabbit model of experimental H. ducreyi infection. However, testing of recombinant attenuated Salmonella strains as vaccine vectors has never been done in rabbits; it is usually done in mice. Anatomic and physiologic differences may limit this approach to the demonstration of vaccine feasibility in rabbits. A three-part study was designed to assess the feasibility of testing attenuated Salmonella vector vaccines in rabbits. The questions asked were, (1) what is the maximum tolerated oral dose and minimum immunogenic oral dose of attenuated Salmonella in rabbits, (2) can a recombinant antigen expressed in the attenuated vector be recognized by the rabbit immune system, and (3) will experimental H. ducreyi infection in rabbits after oral Salmonella vaccination function as a comparative quantitative virulence assay to permit vaccine evaluation? (Abstract shortened by UMI.)

Many countries are reporting of difficulties in exact education at schools: mathematics, informatics, physics etc. Various methods are proposed to awaken and preserve students’ interest in these disciplines. Among them, the simplification, accent on applications, avoiding of argumentation (especially in mathematics) etc. must be mentioned. As one of reasons for these approaches the growing amount of knowledge/skills to be acquired at school is often mentioned. In this paper we consider one of the possibilities to integrate partially teaching of important chapters of discrete mathematics and informatics not reducing the high educational standards. The approach is based on the identification and mastering general combinatorial principles underlying many topics in both disciplines. A special attention in the paper is given to the so-called “pigeonhole principle” and its generalizations. In folklore, this principle is usually formulated in the following way: “if there are n + 1 rabbits in n cages, you can find a cage with at least two rabbits in it“. Examples of appearances of this principle both in mathematics and in computer science are considered.

Northern bobwhite (Colinus virginianus) and swamp rabbits (Sylvilagus aquaticus) are species both strongly influenced by habitat loss and fragmentation in agricultural landscapes. Population declines for the bobwhite and the paucity of information regarding swamp rabbit prevalence add uncertainty to their potential for persistence in Illinois. Research has indicated that these 2 species rarely disperse long distances. In a metapopulation context, such limitations ultimately dictate species' ability to colonize habitat, thereby affecting their persistence. Since gene flow is one of the consequences of dispersal, I employed genetic investigations of the landscape features that affect gene flow, called landscape genetics, to aid the understanding of factors influencing the persistence of the northern bobwhite and swamp rabbit in an agricultural landscape. Tissue samples were collected from hunter harvested bobwhite in central and southern Illinois during 2007-2008. Tissue from trapped swamp rabbits and fecal pellets from swamp rabbit habitat were collected during 2004-2011 in the southernmost counties of Illinois. Microsatellite genetic markers were analyzed for each species. Bayesian clustering methods were used to find interbreeding groups. Levels of gene flow were assessed with F statistics. Correlations between individual genetic distances and landscape features provided an assessment of geographical attributes affecting gene flow. Northern bobwhite expressed less genetic structure among the southern and central counties of Illinois than expected from their sedentary reputation. Genetic differentiation among pre-defined subpopulations was low (FST <0.05) but significant. Genetic clusters were not tightly linked to geography. Individual-based analysis indicated that distance impacted gene flow more than the distribution of suitable habitat or highway barriers. Additionally, the distribution of suitable habitat on the landscape had a negative affect on gene flow indicating bobwhite may disperse through unsuitable habitat more readily than through suitable habitat. These results suggest that greater area of suitable habitat and improvement of existing habitat may be more beneficial to bobwhite than its arrangement or position on the landscape. Significant genetic structure was observed in swamp rabbits in the Cache River watershed of southernmost Illinois. Bayesian clustering indicated 4 distinct genetic groups inhabited the study area. Such structuring suggests swamp rabbits in the northernmost part of their range experience low connectivity among habitat patches and are consequently at risk for extinction in Illinois. Gene flow of swamp rabbits was tied to watercourses indicating their affinity for a water source impacts their dispersal tendencies. Gene flow was negatively impacted by highway barriers, which may interrupt swamp rabbit dispersal due to their avoidance of roads or land cover associated with roads. Alterations to swamp rabbit habitat that leads to loss, increased fragmentation, or increased road density may have severe negative impacts and should be avoided. Habitat improvement focused closer to watercourses may provide a greater benefit for swamp rabbits.

Swamp rabbits (Sylvilagus aquaticus) in southern Illinois exist as a metapopulation due to loss and fragmentation of the bottomland hardwood forests in which they live, making their persistence in the state uncertain. I ran a spatially-explicit population viability analysis (PVA) on the metapopulation, using a habitat suitability map I created and life history parameters drawn from the literature. I varied parameters related to reproduction, survival, catastrophes, dispersal, and carrying capacity from 50 to 150% of the initial value of each parameter to compare their effects on extinction risk. I modified the map to test the effects of potential habitat loss, fragmentation, and the addition of dispersal corridors on the swamp rabbit metapopulation in southern Illinois. Under baseline conditions, the model suggested about a 20% chance of quasi-extinction (90% metapopulation decline) in 25 years. Changes in fecundity values and the effects of catastrophic flooding had the greatest effect on the risk of extinction, causing quasi-extinction probabilities to range from 0 to 100% and 0 to 87%, respectively. In contrast, changing dispersal values yielded the least impact on the risk of extinction (18-24%), and all other parameters had moderate impacts on the model. Removing groups of the largest habitat patches increased the risk of extinction, whereas removing groups of the smallest habitat patches decreased the risk of extinction, suggesting that small patches could act as population sinks with a negative impact on swamp rabbit persistence. Decreasing patch fragmentation per se reduced the risk of extinction slightly. The addition of dispersal corridors made no significant impact on the probability of extinction. My findings indicate that more research estimating fecundity and the effect of catastrophic floods on swamp rabbits in Illinois is required to more accurately predict swamp rabbit persistence in the state. I also suggest that managers should work to decrease the effect of flooding on the population by improving upland habitat, or decrease fragmentation by increasing the area of bottomland hardwood forests around existing habitat patches. Lastly, I suggest managers focus on preventing further habitat fragmentation into small patches, which will mitigate the creation of potential sink populations and will enable current populations to persist.

Public opinion asks for adopting welfare-friendly techniques during rearing of farm animals. The housing system in pairs within wire-net cages (2 rabbits/cage) or small groups (4-8 rabbits/cage), which is currently implemented for rabbits should change and alternative pen housing should be adopted to ameliorate animal welfare in respect of growth performance and meat traits. The farming environment should change and be adjusted to the presence of a large group of animals with diversified social relationships that could be influenced by gender composition and slaughter age. The passage from the conventional housing systems to the new alternative ones cannot be achievable without previous research on the effects of this new system on growth performance and welfare of animals. To achieve this general goal, four trials have been conducted under the present thesis and the summaries of the results obtained are reported below: Trial No. 1-Welfare and productivity of growing rabbits housed in bicellular cages and collective pens Trial No. 2 - Effect of floor type, stocking density, slaughter age, and gender on welfare and productivity of growing rabbits housed in collective pens Trial No. 3–Effect of environmental enrichment and slaughter age on welfare and productivity of growing rabbits housed in collective pens Trial No.4–Effect of different gender composition and floor combinations on welfare and productivity of growing rabbits housed in collective pens On the base of the results of the present Thesis, pen housing may be a succesfull way for growing rabbits giving productive results comparable with those obtained in the current cage systems, but only if housing conditions are suitable for the animals
L’Opinione pubblica richiede l’adozione di techniche “welfare-friendly” per l’allevamento degli animali di interesse zootecnico. L’allevamento del coniglio da carne in gabbie bicellulari (2 conigli/gabbia) oppure in gruppi piccoli (4-8 conigli/gabbia) in gabbie da riproduzione dovrà piuttosto cambiare in un sistema in colonia, in grado di migliorare il benessere animale mantenendo però le prestazioni produttive.Un sistema con gruppi di dimensioni elevate permetterebbe maggiori relazioni sociali, sulla qualità delle quali potrebbero avere un certo effetto la composizione per sessi e l’età di macellazione. Il passaggio dai sistemi convenzionali di gabbia a quelli nuovi e alternativi non potrebbe essere tuttavia possibile senza una valutazione delle conseguenze su prestazioni produttive e benessere animale. Per raggiungere questo obiettivo generale, sono stati realizzati quattro esperimenti di seguito riassunti: Esperimento No. 1–Benessere e produttività di conigli da carne allevati in gabbie bicellulari e recinti collettivi Esperimento No. 2–Effetto di pavimentazione, densità di allevamento, età di macellazione e sesso su benessere e produttività di conigli da carne allevati in recinti collettivi Esperimento No. 3– Effetto del tipo di arricchimento ambientale e dell’età di macellazione su benessere e produttività di conigli da carne allevati in colonia Esperimento No.4 – Effetto della composizione per sesso e del tipo di pavimentazione su benessere e prestazioni produttive in conigli da carne allevati in recinti in colonia Sulla base dei risultati ottenuti dalla Tesi presente, è possibile affermare che l’allevamento dei conigli da carne in recinti collettivi e con dimensioni del gruppo anche relativamente elevate può dare risultati produttivi paragonabili a quelli ottenuti nelle gabbie tradizionali, purché non ci siano condizioni in grado di causare un disagio agli animali

The European rabbit lives in defined social groups of between two and about twenty individuals. There are distinct social hierarchies within each group. Rabbits are known to scent-mark their environment with secretions from several glands, and the secretion of the submandibular cutaneous gland is strongly correlated with social status. Dominant, male rabbits have a higher secretory activity of the gland, and show much more scent-marking behaviour than do any other individuals within the social group. This study was principally conducted at Hope Farm, Cattai National Park in New South Wales, Australia.The proteinaceous components of the secretion varied between individuals, but the protein profile of an individual did not change over time.It was found that dominant rabbits chin mark preferentially at the entrances to warrens, and at the boundaries of their territory.The work in this study provides new insights into the way that rabbit semiochemical messages work. The difference between the secretion of a subordinate and a dominant rabbit appears to be due to the presence or absence of one compound, 2-phenoxy ethanol. This compound, with known fixative properties, supports the idea that the only difference between dominant and subordinate secretions is whether or not they persist in the environment after marking. Such a mechanism for asserting dominance may be much more common in mammals than is apparent from the published literature
Doctor of Philosophy (PhD)

The European rabbit is a keystone prey species in its native range on the Iberian Peninsula, where it is under threat from two viral diseases - myxomatosis and the rabbit haemorrhagic disease virus (RHDV). However, in its alien range the rabbit is considered one of the most damaging pest species, due to overgrazing of pastures and native vegetation. In these areas myxomatosis and RHDV have been deployed as biocontrols for landscape-scale rabbit management. Despite the initial success of viral biocontrols, increases in rabbit abundance were observed between 2003 and 2015, and evolving rabbit genetic resistance to RHDV was proposed as a key cause. Although substantial investment has been made in offsetting such resistance, through the development and introduction of new RHDV strains, the existing co-evolutionary dynamic between rabbits and RHDV in Australia is poorly understood. My thesis uses next-generation sequencing technology to explore the co-evolution of rabbits and RHDV through three approaches, presented as three publication-style manuscripts. In Chapter 2, I pilot the use of blowfly vectors to monitor spatial and temporal variation in RHDV strains. I find that wind-oriented fly traps provide improved efficiency and viral detection rates that exceed previously used rabbit carcass searches. Shotgun sequencing of RHDV capsid amplicons indicated multiple co-circulating local RHDV variants with evidence of recombination between them. This implies that intraspecific competition may play a substantial role in the direction of RHDV evolution, in addition to host resistance. In Chapter 3, I examine the underlying genetic structure of Australia’s rabbit population through a genome-wide selection of SNP loci produced through reduced representation sequencing. I find strong support for three geographically widespread rabbit lineages, as well as three individual sites with strong local differentiation. This genetic structuring is consistent with an invasion history of multiple introductions, rather than the previously assumed single primary invasion front, and may contribute to geographic variance in RHDV resistance. In Chapter 4, I combine long-term capture-mark-recapture data from a single rabbit population with a SNP-based pedigree using reduced representation sequencing. I find evidence of socially structured polygynandry with male-biased dispersal and an unexpectedly high rate of breeding outside warren-based social groups. I also examine the influence on offspring survival of warren size, birth dates and maternal antibodies to RHDV and myxomatosis. This thesis contributes to our understanding of rabbit and RHDV co-evolution by validating a more effective RHDV monitoring tool, characterising the underlying genetic variation in both host and pathogen, and analysing the pressures that drive evolution of this host-pathogen system. These insights provide the building blocks for further research to understand the mechanisms of genetic resistance to RHDV in rabbits, the extent of influence of resistance on rabbit fitness and abundance, and the impacts of current and future biocontrol activities.
Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2019

碩士
台北醫學院
藥學研究所
87
Paeoniflorin is the major constituent of paeoniae radix. In previous papers, paeoniflorin has been demonstrated to release muscle spasm, enhance memory, regulate immunity, anti-inflammatory, inhibit protein binding of steroids, anticoagulative and antihyperglycemic effects. Although paeoniflorin has several pharmacological actions, but the pharmacokinetics of paeoniflorin has not been studied well . An accuracy, simple and specific HPLC method was developed to detect the concentration of paeoniflorin in biological sample firstly. A reverse phase column with UV detection at 238 nm was used in chromatographic separation. The calibration curve of plasma sample shows good linearity within the concentration range of 50 to 50000 ng/ml (r2=0.9993); the calibration curve of urine sample also shows good linearity within the concentration range of 0.5 to 500 mg/ml (r2=0.9992) The coefficients of variation (C.V.) of the intraday and interday validation are all within 10 % . The pharmacokinetics of paeoniflorin was studied by intravenous administration of three different doses (0.5, 5, 25 mg/kg) in six rabbits, respectively. The plasma concentration-time profiles of paeoniflorin could be described by a bi-exponential equation with each dose. There are no significant difference in pharmacokinetic parameters of paeoniflorin under these three doses. The elimination half-life are 27.45*5.23, 32.06*6.89, 31.73*7.92 min, and systemic clearance are 9.78 * 0.96, 8.77*0.49, 8.63*0.71 ml/min/kg . The area under the curves (AUC) calculated from time zero to infinite are 51.67*5.50, 571.93*33.72, 2916.65*246.24 mg*min/ml. It is proportional to the dose administrated (Y=0.04X-0.012, r=0.977, P<0.001). It indicated that paeoniflorin may behave dose-independent pharmacokinetics between 0.5∼25 mg/kg IV injection . In addition, 25mg/kg of paeoniflorin was intraperitoneal administered to rabbits . The plasma concentration-time profiles could be also fitted by one-compartment model . The area under the curve (AUC) was 2992.72*419.54 mg*min/ml. Comparing with that of intravenous administration in the dose of 25mg/kg , the absolute bioavailability of paeoniflorin was 1.03*0.16 through the I.P. administration . After oral administration of paeoniflorin 25 mg/ml , the number of paeoniflorin in plasma was very low . According to duodenum permeability, the ratio of paeoniflorin permeability only was 0.124*0.044% , it is suggested that poor absorption in intestine results low bioavailability from oral administration of paeoniflorin .

碩士
中國醫藥學院
中國藥學研究所
85
Baicalein, an active constituent isolated from the root of Scutellarir baicalensis GEORGI, a frequently use herb in China, possesses antioxidationantitumor, anti-inflammatory and lipid- lowering effect. In this study, thepharmacokinetics and bioavailability of Baicalein in rabbits were evaluated. A simple high performance liquid chromatographic method was developed forthe determination of Baicalein in plasma sample. The pharmacokinetics of Baicalein in the rabbits after intravenous bolusadministration of various doses (2,10 and 50 mg/kg) were well described bya two compartment model. The mean biological half-lives was 71 mins . Theresults also indicated that the pharmacokinetics of Baicalein after I.V.adminstration are linear over the 2-50 mg/kg dose range . The bioavailabilityof Baicalein in rabbits after I.M. administered of 50 mg/kg dose was 68%.However , after oral administered 250 mg/kg dose of same preparation, thebioavailability was only about 29%, it indicated that Baicalein was poorlyabsorbed from the GI tract in rabbits .

碩士
中國醫藥學院
中國藥學研究所
85
Amygdalin, an active constituent isolated from the seed of Pruns armeniaca L., a frequently use herb in China, possesses anti-ulcer, antihypertensive, Antitussive and anti-tumor effect. In this study, the pharmacokinetics and bioavailability of Amygdalin in rabbits were evaluated .A simple high performance liquid chromatographic method was developed for the determination of Amygdalin in plasma sample.The pharmacokinetics of Amygdalin in the rabbits after intravenous bolus administration of 30 mg/kg doses, intramuscular administration of 30 mg/kg doses and oral administered 150 mg/ kg dose were well described by a two compartment model. The mean biological half-lives was 107.8 min after I.M., 161.5 min after P.O.. The results also indicated that the bioavailability of Amygdalin in rabbits after I.M. administered was 86%. , after oral administered was only about 9%, it indicated that Amygdalin was very poorly absorbed from the GI tract in rabbits .