936 resultados para toxicological mortality data


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Eleven species of Amazon parrots (genus Amazona) are known to occur in Brazil, and nest poaching and illegal traffic pose serious conservation threats to these species. When the illegal owners realize these animals are incompatible with their expectations and lifestyle, or when the police arrests traders and owners, these trafficked animals are often considered unfit for release and sent to local zoos and captive breeders. A retrospective survey of animal and necropsy records from 1986 to 2007 was used to evaluate the impacts of animal traffic on the population composition and mortality patterns of Amazon parrots at the Quinzinho de Barros Municipal Zoological Park, Sorocaba, Brazil. Data were obtained for 374 Amazon parrots of ten Brazilian species, and there was evidence that the studied population could be split into two major groups: a majority belonging to the Amazona aestiva species and a minority belonging to the remaining species. In comparison, the animals of the first group were more frequently admitted from traffic-related origins (98 vs. 75%), had a shorter lifespan (median 301 days vs. 848 days) and a higher mortality within the first year postadmission (54 vs. 37%), were less likely to receive expensive treatments, and were more frequently housed off-exhibit. On an average, parrots were found to have a short postadmission lifespan (median 356 days), with 92.5% of the birds dying within their first five years in captivity. The paper discusses the difficult dilemmas these incoming traffic-related animals pose to zoo management and official anti-traffic policies. Zoo Biol 29:600-614, 2010. (C) 2010 Wiley-Liss, Inc.

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Studies on environmental consequences of stress on animal production have grown substantially in the last few years for economic and animal welfare reasons. Physiological, hormonal, and immunological deficits as well as increases in animals` susceptibility to diseases have been reported after different stressors in broiler chickens. The aim of the current experiment is to describe the effects of 2 different heat stressors (31 +/- 1 and 36 +/- 1 degrees C/10 h per d) applied to broiler chickens from d 35 to 42 of life on the corticosterone serum levels, performance parameters, intestinal histology, and peritoneal macrophage activity, correlating and discussing the obtained data under a neuroimmune perspective. In our study, we demonstrated that heat stress (31 +/- 1 and 36 +/- 1 degrees C) increased the corticosterone serum levels and decreased BW gain and food intake. Only chickens submitted to 36 +/- 1 degrees C, however, presented a decrease in feed conversion and increased mortality. We also showed a decrease of bursa of Fabricius (31 +/- 1 and 36 +/- 1 degrees C), thymus (36 +/- 1 degrees C), and spleen (36 +/- 1 degrees C) relative weights and of macrophage basal (31 +/- 1 and 36 +/- 1 degrees C) and Staphylococcus aureus-induced oxidative burst (31 +/- 1 degrees C). Finally, mild multifocal acute enteritis characterized by an increased presence of lymphocytes and plasmocytes within the jejunum`s lamina propria was also observed. The stress-induced hypothalamic-pituitary-adrenal axis activation was taken as responsible for the negative effects observed on the chickens` performance and immune function and also the changes of the intestinal mucosa. The present obtained data corroborate with others in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

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Although many carnivores are of conservation concern, most are poorly studied. The maned wolf Chrysocyon brachyurus Illiger, 1811 is the largest South American canid with a broad distribution; however, the largest portion of its range is in the Brazilian Cerrado savannah, where due to intensive agricultural expansion, it is threatened by habitat loss. Maned wolf population trends are virtually unknown. We analyzed radio telemetry data from a 13-year study in Emas National Park, central Brazil, with Burnham`s live recapture/dead recovery models in the program MARK to obtain the first analytically sound estimate of the apparent maned wolf survival rate. We constructed 16 candidate models including variation in survival rate and resighting probability associated with an individual`s sex or age and year of study. Apparent adult survival rate throughout the study ranged from 0.28 (se=0.08) to 0.97 (se=0.06). There was no evidence for sex specificity but strong support for time variation. Model weights supported an age effect and the subadult survival rate was 0.63 (se=0.15). Results indicate similar life patterns for male and female maned wolves and similar mortality risks for adults and subadults in the study area. The observed temporal fluctuations of adult survival rate are important for population dynamics as they decrease average population growth rates. Population dynamics are central for conservation planning and our results are an important step towards a better understanding of the maned wolf`s ecology.

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There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid-base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.

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