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排序方式: 共有543条查询结果,搜索用时 531 毫秒
81.
82.
Cláudio Eduardo Silva Freitas Eduardo Robson Duarte Dorismar David Alves Isabel Martinele Marta D’Agosto Franciane Cedrola Angélica Alves de Moura Freitas Franklin Delano dos Santos Soares Makenzi Beltran 《Tropical animal health and production》2017,49(4):807-812
A ciliate protozoa suppression can reduce methane production increasing the energy efficiency utilization by ruminants. The physicochemical characteristics of rumen fluid and the profile of the rumen protozoa populations were evaluated for sheep fed banana leaf hay in replacement of the Cynodon dactylon cv. vaqueiro hay. A total of 30 male sheep were raised in intensive system during 15 days of adaptation and 63 days of experimental period. The animals were distributed in a completely randomized design that included six replicates of five treatments with replacement levels (0, 25, 50, 75, and 100%) of the grass vaquero for the banana leaf hay. Samples of fluid were collected directly from the rumen with sterile catheters. Color, odor, viscosity, and the methylene blue reduction potential (MBRP) were evaluated and pH estimated using a digital potentiometer. After decimal dilutions, counts of genus protozoa were performed in Sedgewick Rafter chambers. The averages of pH, MBRP, color, odor, and viscosity were not influenced by the inclusion of the banana leaf hay. However, the total number of protozoa and Entodinium spp. population significantly decreased at 75 and 100% inclusions of banana leaf hay as roughage. 相似文献
83.
Marlos Castanheira Samuel Rezende Paiva Helder Louvandini Aline Landim Maria Clorinda Soares Fiorvanti Giane Regina Paludo Bruno Stefano Dallago Concepta McManus 《Tropical animal health and production》2010,42(2):185-191
The environment in which the horse is reared affects its ability to maintain thermal balance which is in turn related to thermal characteristics and regulatory physiological mechanisms. In this study a multivariate analysis of physiological traits in relation to heat tolerance in horses was carried out in the Federal District, Brazil. The aim was to test the ability of these analyses to separate groups of animals and determine which physiological traits are most important in the adaptation to heat stress. Forty adult horses (4 to 13 years) were used, ten from each of four different genetic groups (English thoroughbred, Brazilian showjumper, crossbred and Breton). The traits examined included heart and breathing rate, rectal temperature as well as blood parameters. The data underwent multivariate statistical analysis including cluster, discriminate and canonical using Statistical Analysis System - SAS ® procedures CLUSTER, STEPDISC, CANCORR and DISCRIM. The tree diagram showed clear distances between groups studied and canonical analysis was able to separate individuals in groups. The discriminate analysis identified the variables which were most important in separating these groups. The multivariate analysis was able to separate the animals into groups with RR, HR and RT being important in this separation. 相似文献
84.
AEM Horta JP Barbas CC Marques MC Baptista MI Vasques RM Pereira RD Mascarenhas S Cavaco‐Gonçalves 《Reproduction in domestic animals》2010,45(6):e412-e416
The effect of vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination (AI) upon the site of AI (vaginal or cervical) and fertility was studied using a total of 87 estrous synchronized Serra da Estrela ewes (control n = 42 and treated n = 45). Artificial insemination was performed using refrigerated semen at 54–55 h after sponge removal. Lambing rate (fertility) and prolificacy were compared between control and treated ewes. The effect of the site of semen deposition on fertility was also evaluated. Prolificacy rate was not different between control (1.5) and treated (1.59) ewes. The proportion of cervical AI achieved in control (45.2%) and treated (37.8%) ewes was not significantly different. Overall, fertility was significantly lower in control than in treated ewes (42.9% vs 64.4%; p < 0.04). Fertility following vaginal AI was significantly lower for control for than treated ewes (30.4% vs 60.7%; p < 0.03) but the difference was smaller and not significant for cervical AI (control 57.9% vs 70.6%). It was concluded that vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination did not affect the proportion of cervical inseminations but significantly improved the fertility of treated ewes. Although needing confirmation, it was hypothesized that drugs might have induced local secretory modifications leading to an increase of cervical ability to retain more viable spermatozoa for fertilization. 相似文献
85.
Felipe Crecente-Campo Margarida Tomé Paula Soares Ulises Diéguez-Aranda 《Forest Ecology and Management》2010
A generalized height–diameter model was developed for Eucalyptus globulus Labill. stands in Galicia (northwestern Spain). The study involved a variety of pure stands ranging from even-aged to uneven-aged. Data were obtained from permanent circular sample plots in which trees were sampled within different radii according to their diameter at breast height. A combination of weighted regression, to take into account the unequal selection probabilities of such an inventory design, and mixed model techniques, to accommodate local random fluctuations in the height–diameter relationship, were applied to estimate fixed and random parameters for several models reported in the relevant literature. The models that provided the best results included dominant height and dominant diameter as fixed effects. These models explained more than 83% of the observed variability, with mean errors of less than 2.5 m. Random parameters for particular plots were estimated with different tree selection options. Height–diameter relationships tailored to individual plots can be obtained by calibration of the height measurements of the three smallest trees in a plot. An independent dataset was used to test the performance of the model with data not used in the fitting process, and to demonstrate the advantages of calibrating the mixed-effects model. 相似文献
86.
87.
Marco F. L. Lemos Cornelis A. M. van Gestel Amadeu M. V. M. Soares 《Journal of Soils and Sediments》2009,9(5):492-500
Background, aim, and scope
In the past decade there has been an increasing awareness about the possible consequences of human and wildlife exposure to endocrine disrupting compounds (EDCs). Bisphenol A (BPA) and vinclozolin (Vz) are EDCs which impacts on vertebrates have been largely investigated. Nevertheless, research on invertebrate effects, especially on soil organisms, are still largely under-represented. This work aims to extend the limited ecotoxicological datasets available and to provide tools to assess the effects of EDCs on the terrestrial species, using Porcellio scaber (Crustacea: Isopoda) as a model organism. 相似文献88.
Tania Vidal Joana Luísa Pereira Nelson Abrantes Amadeu M V M Soares Fernando Gon?alves 《Water, air, and soil pollution》2012,223(9):6009-6023
Metal contamination of freshwater bodies resulting from mining activities or deactivated mines is a common problem worldwide such as in Portugal. Bra?al (galena ore) and Palhal (pyrrhotite, chalcopyrite, galena, sphalerite, and pyrite ore), located in a riverside position, are both examples of deactivated mining areas lacking implemented recovery plans since their shutdown in the early mid-1900s. In both mining areas, effluents still flow into two rivers. The purpose of this work was to evaluate the potential hazard posed by the mining effluents to freshwater communities. Therefore, short- and long-term ecotoxicological tests were performed on elutriates from river sediments collected at each site using standard test organisms that cover different functional levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Lemna minor, and Daphnia sp.). The results show that elutriates from the sediments of Palhal were very toxic to all tested species, while in contrast, elutriates from Bra?al showed generally no toxicity for the tested species. Our study highlights the usefulness of using an ecotoxicological approach to help in the prioritization/scoring of the most critical areas impacted by deactivated mines. This ecotoxicological test battery can provide important information about the ecological status of each concerning site before investing in the application of time-consuming and costly methods defined by the Water Framework Directive or can stand as a meaningful complementary analysis. 相似文献
89.
Landim AV Cardoso MT Castanheira M Fioravanti MC Louvandini H McManus C 《Tropical animal health and production》2011,43(8):1561-1566
This study aims to investigate the effect of breed and slaughter weight on fatty the acid profile of the Longissimus dorsi muscle in lambs. Twenty-four Santa Inês (SI), 24.5 Ile de France × 0.5 Santa Inês (Ile × SI) and 12.5 Texel × 0.5 Santa Inês
(Te × SI), slaughtered at different weights (30, 35, 40, and 45 kg), were evaluated. The animals were reared with creep feeding
to weaning and were feedlot finished, receiving a diet composed of 30% hay and 70% concentrate. The analyses of fatty acids
were carried out on the Longissimus muscle of the 13th rib. The experiment was in a three by four factorial design. The total mean saturated fatty acid level
was 44.88%, with 43.30% monounsaturated fats and 1.72% polyunsaturated. The major fatty acids found included oleic (43%),
palmitic (22%), and stearic (18%). The concentration of desirable fatty acids varied from 61.56% to 66.78%, with Te × SI (66.78%)
having the highest levels (P < 0.05). The slaughter weight affected (P < 0.05) the saturated and unsaturated (both mono and poly) fatty acid profiles. The 35-kg slaughter weight showed the most
desirable fatty acid profile. The saturated myristic and stearic fatty acids decreased with an increase in the slaughter weight,
but oleic acid increased. In the conditions of the present study, the meat from Santa Ines and Texel × Santa Ines lambs had
fatty acid profiles more beneficial for human health due to the higher levels of unsaturated fatty acids. 相似文献
90.
Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis 总被引:1,自引:0,他引:1
Martin V Zhou X Marshall E Jia B Fusheng G FrancoDixon MA DeHaan N Pfeiffer DU Soares Magalhães RJ Gilbert M 《Preventive veterinary medicine》2011,102(3):196-205
Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions. 相似文献