Submitted by (edna.saturno@ufrpe.br) on 2016-10-13T13:00:47Z No. of bitstreams: 1 Joao Menezes Guimaraes.pdf: 673478 bytes, checksum: ef54de7c4a3b2b028a8d0c3258c0eb0f (MD5) / Made available in DSpace on 2016-10-13T13:00:47Z (GMT). No. of bitstreams: 1 Joao Menezes Guimaraes.pdf: 673478 bytes, checksum: ef54de7c4a3b2b028a8d0c3258c0eb0f (MD5) Previous issue date: 2011-02-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The environmental changes during fish culture reflect directly in the animal health, so the physiologic state should be evaluated systematically. It’s important to assess the animal health during whole culture, making possible an intervention as fast as necessary when any anomaly be detected. The hematological exams are an important tools to diagnose early symptoms. The aim of this study was to investigate the hematological reference values for Nile tilapia, Oreochromis niloticus (Cichlidae), cultured in Pernambuco. Were analyzed 109 fishes with weight and length mean of 525g and 27.7cm. Were determined the hematocrit, red blood cells (RBC); white blood cells (WBC); total thrombocyte; differential count of leukocytes expressed in relative and absolute values; hemoglobin concentration; mean corpuscular volume (MCV); mean corpuscular hemoglobin concentration (MCHC) and mean corpuscular hemoglobin (MCH). When evaluated separately the fishes from two different groups according to the culture technique (pond or cage), great heterogeneity was observed between the two groups. The mean value of RBC from tilapia cultured in ponds was 2.14x106/μL and in cages was 1.86x106/μL, being around 15% greater. The mean value of hemoglobin and hematocrit were, respectively, 16.87% and 26.14% greater in the pond cultured fish. Was verified difference (P<0.05) in the mean values of total thrombocyte, WBC and lymphocyte/μL, that were respectively 34.83%, 38.55%, 33.28% greater in tilapia cultured in ponds. These differences demonstrate that generic parameters to tilapia hematology must be used with caution, try when possible to establish specific values to the target population, using as reference in sanity accompaniment. / As alterações ambientais no cultivo refletem diretamente na saúde animal, necessitando, por isso, avaliar sistematicamente o estado fisiológico. É importante ter um acompanhamento do estado animal durante todo o cultivo, possibilitando uma rápida intervenção quando for detectada qualquer anomalia. Os exames hematológicos é uma importante ferramenta para um diagnostico ou sinalização precoce e por isso objetivou-se com este estudo investigar os valores hematológicos para a tilápia do Nilo, Oreochromis niloticus (Cichlidae), cultivadas em Pernambuco. Foram analisados 109 peixes, com peso e comprimento médios de 525g e 27,7cm. Foram determinados o hematócrito, contagem de eritrócitos, leucócitos totais, trombócitos totais, contagem diferencial de leucócitos expressa em valores relativos e absolutos, taxa de hemoglobina, volume corpuscular médio (VCM), concentração de hemoglobina corpuscular média (CHCM) e hemoglobina corpuscular média (HCM). Ao avaliar separadamente os peixes classificados em dois grupos, de acordo com a técnica de cultivo (viveiro e tanques-rede) observou-se grande heterogeneidade entre os dois grupos. O valor médio de eritrócitos de tilápias cultivadas em viveiro foi 2,14x106/μL e em tanque-rede de 1,86x106/μL, sendo em torno de 15% maior, assim como as médias de hemoglobina e de hematócrito, que foram respectivamente, 16,87% e 26,14% maiores para os peixes de viveiro. Também foi verificado diferença nas médias de trombócitos totais, leucócitos totais e linfócitos/μL, que foram 34,83%, 38,55%, 33,28% maiores no sangue das tilápias cultivadas em viveiro. Tais diferenças demonstram que perfis genéricos para hematologia de tilápias devem ser usados com cautela, devendo-se sempre que possível estabelecer valores específicos para a população que se quer aferir os parâmetros, para servirem como referência no acompanhamento da sanidade.

Made available in DSpace on 2014-06-12T15:52:03Z (GMT). No. of bitstreams: 2 arquivo3131_1.pdf: 596856 bytes, checksum: 6ecd36106eae78833584c1e83095f1fe (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Tilápia do Nilo (Oreochromis niloticus) é um dos peixes mais populares de criação no mundo, tem excelente adaptação e reprodução em ambientes lênticos e possui filé de alta qualidade. Além das peças limpas e comestíveis do pescado, há uma quantidade substancial de resíduos de peixe. Muitas vezes, esse remanescente de resíduos é despejado em rios, causando um desequilíbrio ambiental. Carcaças e vísceras de tilápia têm um alto valor protéico a ser usado na produção de alimentos para organismos aquáticos. A utilização de resíduos de pescado diminui o risco de poluição ambiental e gera receitas econômicas. Estudos mostraram que os resíduos podem ser usados na recuperação de compostos úteis, incluindo proteínas que têm atividade antimicrobiana. O presente trabalho relata a presença de inibidor de tripsina de tilápia no fígado, estômago e intestino, bem como a purificação do inibidor de tripsina O. niloticus (OnTI) e atividade antibacteriana do fígado, víscera de maior atividade inibidora de tripsina específica. As vísceras foram separadas e homogeneizadas com 0,15 M NaCl e os homogeneizados foram tratados com sulfato de amônio. Concentrações de proteínas das frações dos precipitados e sobrenadantes foram dosadas, aquecida a 80 ° C por 1 h, e avaliadas quanto à atividade do inibidor de tripsina. O precipitado da fração 20-40% de fígado (LF20-40) de alta atividade inibidora de tripsina específica foi utilizado para purificação do inibidor e em testes de atividade antibacteriana; sendo determinadas as concentrações inibitórias mínima (CIM) e bactericidas (CBM). Frações de sulfato de amônio de fígado e estômago apresentaram atividade do inibidor de tripsina superior às frações de intestino. O. niloticus inibidor de tripsina (OnTI) ligado à coluna Tripsina-Agarose foi eluído com 0,5 M KCl-HCl pH 2,0. OnTI apresentou atividade específica de 950 U / mg e duas bandas de proteínas em SDS-PAGE. A atividade antibacteriana sobre S. aureus foi detectada pela LF20-40 (MIC: 0,09 mg / mL; MBC: 0,76 mg / mL), a fração também foi capaz de inibir o crescimento de K. pneumoniae (MIC: 1,53 mg / mL), mas não apresentou atividade antibacteriana contra E. coli. Os resultados revelaram que o fígado e estômago de tilápia contem inibidor de tripsina. O efeito da preparação do fígado de tilápia sobre S. aureus e K. pneumoniae, indica que esta víscera, normalmente descartada como resíduo, é uma fonte potencial de agentes antibacterianos

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-07-28T13:29:06Z No. of bitstreams: 1 Misleni Ricarte de Lima.pdf: 853509 bytes, checksum: 2ab96c25d5d0afdb4c230cb5e63c6d7b (MD5) / Made available in DSpace on 2017-07-28T13:29:06Z (GMT). No. of bitstreams: 1 Misleni Ricarte de Lima.pdf: 853509 bytes, checksum: 2ab96c25d5d0afdb4c230cb5e63c6d7b (MD5) Previous issue date: 2014-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The research was conducted at the Department of digestibility Not Ruminants, Department of Animal Science, Federal Rural University of Pernambuco, with the aim of evaluating the use of byproducts protein in diets for Nile tilapia (Oreochromis niloticus) on the parameters of performance and carcass characteristics. Three experiments were performed to evaluate performance of the following byproducts: cane yeast at levels 0, 10, 20 and 30% inclusion (Chapter 2), poultry by-products 0, 6, 12 and 18% (Chapter 3) castor meal 0, 3, 6 and 9% inclusion (chapter 4). The experimental design for all experiments was a completely randomized design consisting of four treatments and six replications in each experiment, we used 144 male fingerlings of Nile tilapia, sexually inverted distributed in 24 polyethylene tanks with a capacity of 80L each, interconnected in a recirculating system with water using biological filter. At the end of each experimental period were evaluated: weight gain, feed intake, feed conversion ratio, protein efficiency rate, survival rate, weight and carcass yield, weight and trunk yield, hepatosomatic index and abdominal fat index. The conditions under which the tests were performed, it can conclude that the best level of spray dried yeast for Nile tilapia is up to 10% for poultry viscera meal is 18% and the inclusion of castor bean bran negatively influences the final weight, weight gain, weight and carcass yield of Nile tilapia. / A pesquisa foi conduzida no Setor de digestibilidade de Não Ruminantes do Departamento de Zootecnia da Universidade Federal Rural de Pernambuco, com o objetivo de avaliar a utilização de subprodutos de origem proteica em dietas para alevinos de tilápia do Nilo (Oreochromis niloticus) sobre os parâmetros de desempenho produtivo e característica de carcaça. Foram executados três experimentos de desempenho para avaliar os seguintes subprodutos: levedura de cana spray dried nos níveis 0, 10, 20 e 30% de inclusão (capítulo 2), a farinha de vísceras de aves 0, 6, 12 e 18% (capítulo 3) e o farelo de mamona 0, 3, 6 e 9% de inclusão (capítulo 4). O delineamento experimental utilizado para todos os experimentos foi o inteiramente casualizado composto de quatro tratamentos e seis repetições, em cada experimento, foram utilizados 144 alevinos machos de tilápia do Nilo, revertidos sexualmente, distribuídos em 24 aquários de polietileno com capacidade de 80L cada, interligados em um sistema de recirculação de água com uso de filtro biológico. Ao término de cada período experimental, foram avaliados: ganho de peso, consumo de ração, conversão alimentar aparente, taxa de eficiência proteica, taxa de sobrevivência, peso e rendimento de carcaça, peso e rendimento de tronco, relações hepatossomática e lipossomática. Nas condições em que foram realizados os ensaios, pode-se incluir a levedura spray dried em dietas para alevinos de tilápia do Nilo até 10%, para a farinha de vísceras de aves até 18% e a inclusão do farelo de mamona influencia negativamente o peso final, ganho de peso, peso e rendimento de carcaça dos alevinos de tilápia do Nilo.

The objective of this study was to determine the dietary protein requirements of the Nile crocodile (Crocodylus niloticus) between the ages of 5 – 8 months, and to compare the results with documented protein requirements of the American alligator (Alligator mississippiensis). This was achieved by feeding the crocodiles 4 diets with varying amounts of crude protein (CP), including 62%, 56.6%, 51.6% and 46%. All four diets were iso-energetic with a metabolisable energy to protein ratio of 25.85KJ/g. The highest protein diet contained 44% raw minced chicken and 46.9% fish meal with minimal contribution (of 6.4%) made from vegetable protein sources (full fat soya). The lowest protein diet was made up of a majority of vegetable protein (30% soya bean oilcake, 9.8% full fat soya and 17.2% maize meal) and some contribution from protein of animal origin (4.3% carcass meal and 35% fish meal). This study was carried out for 12 weeks during the crocodiles first year of life. Body mass, total body length, head length and snout to vent length were measured five times at 3 weekly intervals. Twenty representative crocodiles in a pen of 200 were individually tagged for the duration of the trial. As there were 3 replicates for each of the 4 treatment diets, 240 crocodiles in 12 pens were tagged. During the early phase of the study, it was observed that crocodiles on the 46% CP treatment diet were not performing well, and that most of the crocodiles on this diet were losing mass. This treatment diet was discontinued at 9 weeks into the trial for both financial and ethical reasons. The remaining three diets were tested for the full 12 weeks. Chromium oxide was mixed into the diets at two time periods during the trial to determine the protein, energy and dry matter digestibility. It was determined that the 46%, the 51.6%, the 56.6% and the 62% CP diets had a digestible protein (DP) content of 246.44 g/kg, 294.80 g/kg, 381.32 g/kg and 468.65 g/kg and a digestibility coefficient of 53.50%, 57.00%, 69.15% and 75.65% respectively. Performance of crocodiles on the 46% CP treatment diet was found to be lower in all measurement categories than crocodiles on the three higher protein diets. However, crocodiles on the 62% CP treatment diet outperformed all the crocodiles (on all measurement criteria) on the lower protein diets. The poor performance of crocodiles on the lowest protein diet correlates with previous research indicating that crocodilians are unable to perform optimally when the majority of the diet’s protein is made up of vegetable protein sources. It was determined that juvenile American alligators would grow at optimal levels when the diet contained a DP content of 450 g/kg. As the Nile crocodiles in this study performed the best when the diet contained a DP value of 468.65 g/kg, it was concluded that juvenile Nile crocodiles have the same range of protein requirements as that determined for juvenile American alligators. / Dissertation (MSc(Agric))--University of Pretoria, 2011. / Animal and Wildlife Sciences / unrestricted

Urine samples are routinely used in human and animal patients to diagnose health problems; often to investigate or monitor specific health-related problems that essentially may remain silent for extended periods. However, not much work has been performed on crocodilian urine for diagnostics. In general, crocodilian species lack a bladder as a separate storage organ (as found in mammals), possess metanephric kidneys (unable to concentrate urine) and have functional salt excreting glands. Collection of urine from the Nile crocodile (Crocodylus niloticus) is a simple and atraumatic procedure where a dog urinary catheter is used to collect relatively clean urine from the urinary chamber in the crocodile’s cloaca. Unfortunately, in-depth investigations of urine variables, and establishing baseline concentrations, have not been performed on Nile crocodile urine samples before. The specific focus areas of this research project were: (1) determination of urine and plasma biochemical concentrations by means of a standard veterinary clinical pathology profile and the establishment of the ratio between urine and blood biochemical parameters; (2) the validation of a gas chromatographic–mass spectrometric (GC/MS) method for the determination of steroid metabolite concentrations in urine; and (3) using this established analytical method to determine the presence (identify) and concentrations of steroid metabolites in the urine of individual crocodilians. / Urine and plasma samples collected at Izintaba Crocodile Farm during the period November 2005 to July 2006, from captive bred, healthy young Nile crocodiles, were analysed for standard biochemistry variables. The urine samples (n = 101) were analysed for sodium, potassium, chloride, urea, creatinine, calcium, magnesium, phosphate, uric acid, osmolality, and ammonium ion, while the plasma samples (n = 101) were screened for total protein, glucose, sodium, potassium, chloride, urea, creatinine, total calcium, ionised calcium, magnesium, phosphate, uric acid and osmolality. Means, medians and standard deviations were statistically determined, as well as urine to plasma (U/P) ratios for corresponding variables. The value of this project is the establishment of reference concentrations for Nile crocodile urine samples that may become useful for interpretation of laboratory results, in future. / The clinical validation of a GC/MS method for the analysis of urinary steroids in the Nile crocodile was achieved using urine samples from two-year-old Nile crocodiles. The main objective of this investigation was to develop, optimize and validate the laboratory analysis of urinary steroid metabolites. Steroid profiling was performed on individual and pooled Nile crocodile urine samples. Ascending concentrations of representative steroid standards: androsterone, etiocholanolone, dehydroepiandrosterone, 11-OH androsterone, pregnanediol, pregnanetriol, 11-deoxytetrahydrocortisol, tetrahydrocortisone, tetrahydrocortisol and tetra-hydrocorticosterone, were spiked into aliquots of the pooled urine samples, to obtain calibration samples ranging from 0.2 to 20 μg. Sample preparation and analysis methodology were based on a well-established, validated GC/MS method for determination of human urinary steroid metabolites. The validation of the GC/MS method for Nile crocodile urine was successfully completed, by determining lower limits of quantitation and limits of detection for each analyte, obtaining linearity up to the highest calibration level, correlations exceeding 0.90, and recoveries of 82% and more. / Steroid profiling was performed on urine samples collected from a number of mature crocodilian species, namely Nile crocodile, American alligator (Alligator mississippiensis), spectacled caiman (Caiman crocodilus) and dwarf crocodile (Osteolaemus tetraspis). Steroid metabolites were identified and were quantitated and reported per urinary creatinine. Qualitative reporting was conducted in cases where creatinine concentrations were not available. Results included identification and quantitation of the steroid metabolites: androsterone, etiocholanolone, 11-hydroxy androsterone, pregnanediol, pregnanetriol, and the tetrahydro- metabolites of cortisone (THE), cortisol (THF), and corticosterone (THB). In some urinary steroid profiles, several prominent peaks were observed which could not be identified. The study findings confirmed that crocodile urine could successfully be used, as it is commonly used in humans, to determine steroid metabolite profiles. A follow-up study to identify the unknown peaks by structure elucidation with more sophisticated equipment is recommended - this could lead to valuable information about liver metabolism of steroids in crocodilians. / An adrenocorticotrophic hormone (ACTH) stimulation test was conducted on 18 captive Nile crocodiles. The experimental animals were temporarily housed in separate enclosures at Le Croc Crocodile Farm for four weeks, to ensure controlled conditions and easy and frequent access to the animals. Twenty-seven urine samples were collected both pre- and post-ACTH or saline injections. Steroid profiling was performed on 24 of the 27 urine samples to assess the corticosterone and tetrahydrocorticosterone concentrations following the ACTH treatment. Quantitation relative to urine creatinine levels was recorded following analyses with a standardised liquid chromatography/mass spectrometry (LC/MS) method, reporting the concentrations in nmol steroid/μmol creatinine. Unfortunately, a significant increase in urinary corticosterone concentrations 6 h after the injection of Synacthen® (5 μg/kg) was not observed. A possible explanation for this could be that the 6 h period was too short for a significant increase in urinary glucocorticoid metabolite excretion in the Nile crocodile. / In conclusion, this is the first in-depth study that focused, specifically, on Nile crocodile urine for analyses as diagnostic tools and for indices of health. The screening of the urine samples, collected from healthy Nile crocodiles, for a large array of biochemical variables contributed significantly to the database of “normal” concentrations. The establishment of a validated urinary steroid profiling method may significantly contribute to future validation and implementation of innovative diagnostic methods to monitor the health status and endocrine systems of wild Nile crocodiles in Africa. / Thesis (PhD)--University of Pretoria, 2017. / The Norwegian Council for Higher Education’s Programme for Development, Research and Education (NUFU) / Royal Netherlands Embassy in South Africa / Crocodile Specialist Group / SAVF / Paraclinical Sciences / PhD / Unrestricted

The Nile crocodile (Crocodylus niloticus) is one of 23 extant crocodilian species, and has been farmed in southern Africa since the 1960s. For the crocodile industry, chronic stress and its often negative consequences are a concern, since stressors can negatively affect animal production as well as the health of the crocodiles. When confronted with a stressor, an individual displays a stress response consisting of a suite of physiological and behavioral alterations to cope with the challenge. So far, however, no method for determining stress-related responses in Nile crocodiles has been established. In other crocodilians, the assessment of physiological responses to stress, like the related alterations in glucocorticoid concentrations, has already been done, but only by using an invasive approach, with the disadvantage of a possible handling-induced stress response. By establishing a non-invasive technique to monitor glucocorticoid levels in captive Nile crocodiles based on faecal hormone analysis, this study not only made an important contribution to a better understanding of stress and related hormonal changes in Nile crocodiles, but also provided a solid basis for developing similar non-invasive tools to collect information on the level of stress experienced by other crocodilians. Specifically the study aimed 1) to assess adrenocortical activity in Nile crocodiles by measuring faecal glucocorticoid metabolite (FGM) concentrations, and 2) to characterise changes in FGM levels in captive Nile crocodiles in relation to different housing conditions. An adrenocorticotropic hormone (ACTH) challenge was performed on 10 sub-adult crocodiles at Le Croc crocodile farm, South Africa, resulting in serum corticosterone levels of up to ~1200 %, 1 - 5 hours post-injection, above the pre-injection levels. An additional 8 individuals were exposed to electric immobilisation and handling only (control group), which resulted in a 20 – 2700 % elevation in serum corticosterone concentrations, indicating that handling was already a sufficient stressor. FGM levels in 3 singly housed animals (2 ACTH challenge; 1 handling only) reached peaks of 136 – 380 % above pre-injection levels at about 7 to 15 days following treatment, demonstrating that non-invasive hormone monitoring can be used for assessing adrenocortical function in captive Nile crocodiles based on FGM analysis. By assessing the impact of group size (n = 1, 2, or 4 individuals) on FGM levels, highest mean hormone values were found in the paired animals. A possible explanation for this finding could be that the necessary re-grouping for the study resulted in an unstable group composition, especially for the paired animals of similar size, which is reflected in comparable higher FGM concentrations. However, future research would be necessary to investigate this potential relationship in more detail. My study created opportunities to improve the management and welfare of farmed crocodiles in terms of more appropriate housing conditions and husbandry for these animals. Finally, the now established non-invasive method for monitoring adrenocortical function in Nile crocodiles provides a solid basis for further studies focusing on monitoring factors influencing adrenocortical function in populations of Nile crocodiles in the wild. / Dissertation (MSc)--University of Pretoria, 2012. / Paraclinical Sciences / unrestricted

Since the first report of Mycoplasma-associated polyarthritis in farmed Nile crocodiles in 1995, the disease has spread across Zimbabwe and South Africa and has resulted in significant economic losses on infected farms. Due to poor response to antimicrobial treatment and frequent relapses, the use of an autogenous vaccine to manage disease outbreaks was evaluated. Two previous trials had been performed with a similar vaccine and the results suggested that the vaccine could be effective in alleviating disease, although the numbers of animals were limited in both. This trial aimed to evaluate an inactivated, alum-adjuvanted M. crocodyli whole-cell vaccine in a large group of yearling crocodiles under field conditions on a farm in Zimbabwe where repeated M. crocodyli outbreaks have been reported. The safety of the vaccine was assessed by administrating the vaccine intraperitoneally to a subset of crocodiles. No adverse clinical reactions were observed in any of these crocodiles. A group of two thousand two hundred crocodiles received two intramuscular vaccinations four weeks apart in the autumn of 2011, while another group of two thousand two hundred crocodiles served as unvaccinated controls. Serum was collected from a subset of the vaccinated and unvaccinated crocodiles at different time-points before and after vaccination to evaluate the humoral response to vaccination. Latex slide agglutination tests (LAT) were performed on all samples and positive samples were titrated with the latex slide agglutination test and metabolism inhibition assay. A low percentage of sera were positive with serological tests done prior to vaccination, suggesting either circulating Mycoplasma or maternal immunity. Statistically significant increase in sero-positivity was detected with LAT four weeks after primary vaccination, although the titre remained low. Six weeks after the booster vaccination the percentage seropositive vaccinated crocodiles had decreased and there were no statistically significant difference between the percentage seropositive vaccinated and unvaccinated crocodiles. A significant outbreak of Mycoplasma-like polyarthritis was encountered 6 months after vaccination, in October 2011. Both vaccinated and unvaccinated crocodiles were affected. Serum samples from different subsets of crocodiles were collected and evaluated similar to the vaccine trial. The results indicated that a similar rate of sero-positivity was present in all crocodiles, irrespective of vaccination- or disease status Sera collected during this trial was used to evaluate the performance of the latex slide agglutination assay compared to the metabolism inhibition assay (“Gold standard” assay), as the performance of the LAT had not been evaluated previously. The calculated diagnostic sensitivity was 72%, diagnostic specificity was 32%, the predictive value of the positive test was 36% while the predictive value of the negative test was 69%. This trial indicated that the autogenous, inactivated, alum-adjuvanted, whole-cell vaccine against M. crocodyli was not able to protect farmed Nile crocodiles on an infected farm against clinical Mycoplasma-associated polyarthritis. It was also found that the latex slide agglutination assay could be useful as a robust, pen-side assay to evaluate exposure to M. crocodyli, although other assays, such as PCR, bacterial culture or growth inhibition assays, has to be performed to confirm the presence of disease. / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

In view of the paucity of detailed information in the literature relevant to the upper digestive tract of the Nile crocodile, this study describes the morphological and histological features of the oral cavity (gingivae, palate and tongue), pharyngeal cavity and oesophagus of the Nile crocodile, Crocodylus niloticus (Laurenti, 1768) using light microscopy. The findings, which were supplemented by scanning electron microscopy, were compared with published information. The ciliated component of the oesophagus was also examined using transmission electron microscopy. The oral cavity had the form of a triangle and was dorso-ventrally flattened. The dorsal limit was formed by the palate and the ventral limit by the broad-based tongue. The close proximity of the tongue and palate severely limited the space within the cavity. The caudal border of the cavity was formed by the dorsal and ventral components of the gular valve. The epithelium of the palate, gingivae and tongue was stratified squamous in nature and appeared lightly keratinised. Specialised epithelial structures in the palate, gingivae and tongue, revealed by both light microscopy (LM) and scanning electron microscopy (SEM), bore characteristics resembling structures responsible for pressure and taste reception. Glandular tissue in the tongue was arranged in a triangular formation in the posterior region and displayed morphological features ascribed to salt secreting glands described in other Crocodilia. There were no palatine glands in the oral region of the palate, except that the oral surface of the dorsal gular fold contained branched tubular mucus secreting glands. The pharyngeal cavity was also dorso-ventrally flattened and was bordered rostrally by the flaccid dorsal gular fold, which displayed a median apical notch, and the ventral gular fold, which was supported internally by the broad rostral tip of the basihyal plate (hyaline cartilage). In the occluded mouth, the dorsal gular fold and the more rostrally positioned ventral component of the gular valve isolated the pharyngeal cavity. This arrangement is essential in preventing the crocodile from drowning (flooding of the pharyngeal cavity) while capturing prey. The roof of the pharyngeal cavity was characterised by the opening to the internal nares (an extension of the nasal passage from the external nares), the fibrous Eustachian plug sealing the common opening to the paired Eustachian ducts and a nodular tonsillar region, which was situated caudo-laterally to the Eustachian plug. Throughout this region, the epithelium was typically ciliated with goblet cells. However, the tonsillar nodules displayed regions of partial or no ciliation on their surface. SEM and stereomicroscopic observations showed fine longitudinal mucosal folding throughout the pharynx the distension of which, together with the large capacity for mucus production (produced by intraepithelial glands and mucus secreting glands), would facilitate the swallowing of large chunks of food in the living state. The ventrally situated laryngeal mound containing the slit-like glottis also displayed longitudinal folds and a ciliated epithelium. Anatomically, the oesophagus could be divided into two clear regions. The cranial, approximate two-thirds appeared broad and flabby. At the tracheal bifurcation, the oesophagus narrowed significantly and indicated a greater muscular content, confirmed by light microscopy. LM and SEM examination of the oesophagus, however, revealed three regional components, viz., the cranial, mid- and caudal regions. In the cranial region, the epithelium was densely ciliated with intervening goblet cells being present. In the mid-region the ciliated component decreased with a concomitant increase in the goblet cell component. In the caudal region there was a further decrease in the number of ciliated cells and a higher concentration of goblet cells. Transmission electron microscopy (TEM) of the ciliated component of the oesophagus showed typical ultrastructural features of both the ciliated and goblet cells. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2002. / Anatomy and Physiology / unrestricted

This investigation illustrates the topography, gross anatomy, histology and ultrastructure of the liver and gallbladder of the Nile crocodile in order to fill the gap that exists in the literature regarding this important crocodilian. For the topographical and macroscopical descriptions the livers and gallbladders were obtained from the carcasses of slaughtered juvenile Nile crocodiles. Perfusion and immersion fixation of tissues for histology and transmission electron microscopy were performed on juvenile Nile crocodiles donated to the university. Published descriptions of other vertebrates were inevitably relied upon for comparison due to the lack of information on these two organs of the Nile crocodile. The liver was located in its own coelomic cavity with the post-pulmonary and the post-hepatic membranes intimately associated with the cranial and caudal surfaces of the bi-lobed liver respectively. The right lobe was larger than the left lobe and they were located at the level of the third to seventh intercostal spaces with their extremities extending to the ninth intercostal space. The triangular shaped liver lobes were joined dorso-medially by a narrow isthmus consisting of liver tissue. The liver was covered by Glisson’s capsule. Central veins, sinusoids and portal tracts were distributed haphazardly with no visible lobulation. The parenchymal component occupied the largest part of the liver and was formed by anastomosing and branching cell cords consisting of two-cell-thick plates in the longitudinal sectional plane and at least five hepatocytes in the cross-sectional plane. Central bile canaliculi contained microvilli originating from apical hepatocyte surfaces and were sealed off by junctional complexes. Hemosiderin granules, bile pigments, melanin pigments, lipid droplets, cholesterol ester slits and glycogen granules were observed in addition to the normal hepatic cytoplasmic organelles. Non-parenchymal cells consisted of endothelial cells, Kupffer cells, stellate cells and pit cells localized in and around the angular sinusoids. The space of Disse existed between endothelial cells and the base of the hepatocytes which was lined by microvilli. Endothelial cells were flat cells with long fenestrated cytoplasmic extensions that lined the sinusoidal wall and contained numerous endocytotic vesicles and many lysosomes. Pleomorphic Kupffer cells were located in the sinusoidal lumen, in the space of Disse and within groups of hepatocytes. They were often situated between groups of hepatocytes, connecting two adjacent sinusoids. Large phagosomes were present in the Kupffer cells and contained a combination of melanin and hemosiderin granules as well as ceroid. Phagocytosis of apoptotic and dying cells was evident. Conspicuous groups of membrane-bound tubular organelles with a filamentous or crystalline interior were present in the Kupffer cells. Stellate cells occupied a subendothelial position in the space of Disse and contained prominent lipid droplets that indented the nuclei. A solitary cilium was infrequently found projecting into the space of Disse. Myofibroblastic cells were found in the same region as stellate cells. Pit cells with indented eccentric nuclei were found in the sinusoidal lumen and in close contact with endothelial and Kupffer cells. Numerous small electron-dense membrane-bound cytoplasmic granules were present. Occasional intercalated cells resembling lymphocytes were seen in the space of Disse and forming part of the groups of hepatocytes. Glisson’s capsule extended collagenous trabeculae into the parenchymal interior and variably sized trabeculae randomly traversed the liver tissue. Portal tracts were enmeshed by a collagenous network that contained fibroblasts, lymphocytes, plasma cells and phagocytes. Portal triads consisted of branches of the portal vein, hepatic artery and bile duct with lymphatic vessels sometimes in accompaniment. Reticular fibres were positioned around hepatocyte tubules and a basal lamina supported the hepatocytes adjacent to Glisson’s capsule. Occasional unmyelinated nerve axons were present. The isthmus contained liver tissue with similar parenchymal and a non-parenchymal components. Three anatomical zones were identified in the pouch-like gallbladder that was attached caudally to the right liver lobe in the dorso-medial region. The gallbladder wall consisted of pseudostratified columnar epithelium, a lamina propria, a muscularis externa and a serosal layer. The accumulation of apical secretory granules, apical bulging, exocytosis of mucous granules and the desquamation of the apical portions of the epithelial cells into the lumen indicated different stages of the mucus secretory cycle. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Anatomy and Physiology / Unrestricted

O objetivo do presente estudo foi avaliar a hipótese de que a inclusão de licopeno na ração comercial reduz os efeitos negativos do estresse e melhora o desempenho de juvenis da tilápia do Nilo, Oreochromis niloticus. Para tal, foi realizado, primeiramente, um estudo que avaliou o efeito da suplementação com licopeno (100, 200, 400 e 800 mg/kg de ração) sobre a atrato-palatabilidade da ração. Numa segunda etapa foi avaliado o efeito da suplementação diária de licopeno (800 mg/kg de ração), durante 60 dias, na promoção do bem-estar de juvenis dessa espécie submetidos a estresse de contenção de 90 minutos. Foram avaliados parâmetros zootécnicos como ganho de peso, conversão alimentar, fator de condição e taxa de crescimento especifico, consumo e parâmetros fisiológicos e bioquímicos como o nível de cortisol plasmático, o conteúdo de peroxidação lipídica, avaliação da cor instrumental do file e a atividade das enzimas antioxidantes catalase (CAT) e glutationa redutase (GR) e atividade da lactato desidrogenase (LDH) no músculo branco (file) e vermelho. Os resultados foram submetidos a ANOVA e em caso de efeito significativo entre tratamentos, as medias foram comparadas pelo teste de Tukey (p<0,05). A inclusão de licopeno não alterou a atrato-palatabilidade da ração comercial em nenhuma das concentrações estudadas. A suplementação com licopeno (800 mg/kg de ração) não alterou nenhum dos parâmetros zootécnicos avaliados: ganho em peso, conversão alimentar, fator de condição e taxa de crescimento especifico. Da mesma forma, não alterou o nível de peroxidação lipídica avaliado pelas substancias reativas ao acido tiobarbitúrico (TBARS) e a cor instrumental do file dos peixes. Houve redução (34%) na atividade da catalase no músculo branco dos peixes suplementados com licopeno, comparado aos animais do grupo controle (sem suplementação). Entretanto, a atividade de catalase na musculatura vermelha não foi alterada mediante a suplementação com licopeno; bem como a atividade da GR e LDH no músculo branco e vermelho. Evidenciou que o estresse de contenção aumenta o nível de cortisol plasmático (53%), o nível de peroxidação lipídica do file (28%) e também a atividade de CAT, GR e LDH no músculo branco (31%, 32% e 29%, respectivamente) e músculo vermelho (48%, 46% e 44%, respectivamente) dos animais submetidos ao estresse. Porem, a inclusão de licopeno na dieta aboliu os efeitos negativos do estresse de contenção, evitando a elevação dos níveis de cortisol, conteúdo de TBARS do file e atividade das enzimas CAT, GR e LDH no músculo branco e vermelho. Concluiu-se que o licopeno veiculado na ração comercial, na proporção de 800 mg/kg de ração, reduz os efeitos negativos do estresse e não altera o desempenho de juvenis de tilápia do Nilo. / The aim of this study was to evaluate the hypothesis that the inclusion of lycopene in the commercial diet reduces the negative effects of stress and improves performance of juvenile Nile tilapia, Oreochromis niloticus. To this end was accomplished, first, a study that evaluated the effect of supplementation with lycopene (100, 200, 400 and 800 mg/kg of diet) on the attraction and palatability of the diet. In a second step, the effect of daily supplementation of lycopene (800 mg/kg of diet) for 60 days, to promote the welfare of juveniles subjected to restraint stress for 90 minutes. Zootechnical parameters were evaluated as weight gain, feed conversion, condition factor and specific growth rate, consumption and physiological and biochemical parameters as the plasma cortisol level, the content of lipid peroxidation, instrumental color of the fillet and the activity of antioxidant enzymes catalase (CAT) and glutathione reductase (GR) and activity of lactate dehydrogenase (LDH) in white muscle (fillet) and red muscle. The results were submitted to ANOVA and in case of significant effect between treatments, means were compared by Tukey test (p<0.05). The inclusion of lycopene did not affect the attraction and palatability of commercial feed in any of the concentrations studied. Supplementation with lycopene (800 mg/kg diet) did not alter any of the zootechnical parameters evaluated: weight gain, feed conversion, condition factor and specific growth rate. Likewise, did not alter the level of lipid peroxidation evaluated by thiobarbituric acid reactive substance (TBARS) and instrumental color of the fillet of fish. There was a reduction (34%) in catalase activity in white muscle of fish supplemented with lycopene, compared to the control group (no supplementation). However, catalase activity in red muscle was not altered by supplementation with lycopene, as well as GR activity and LDH in white muscle and red. It was demonstrated that restraint stress increased the plasma cortisol level (53%), level of lipid peroxidation of the fillet (28%) and activity of CAT, GR and LDH in white muscle (31%, 32% and 29%, respectively) and red muscle (48%, 46% and 44%, respectively) of animals subjected to stress. However, dietary supplementation with lycopene abolished the negative effects of stress restraint, avoiding high levels of cortisol, the TBARS content of the fillet and activity of enzymes CAT, GR and LDH in white muscle and red. It was concluded that lycopene aired the commercial feed at a ratio of 800 mg/kg of diet, reduces the negative effects of stress and does not alter the performance of juvenile Nile tilapia.