987 resultados para Seasons of the year


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The objective of this study was to evaluate performance and daytime ingestive behavior of 84 Nellore young bulls in the post-weaning phase kept on Brachiaria brizantha cv. Marandu pastures during the dry season. Treatments were protein mineral supplementation (1 g/kg body weight) and protein+energy mineral supplementation (3 g/kg body weight). The experimental area comprised 12 paddocks in a total area of 27.36 ha, divided in two blocks of six paddocks each, having three replications per treatment in each block, with 42 animals/treatment. The data were subjected to variance analysis with repeated measures over time via procedure PROCMIXED of SAS (Statistical Analysis System, version 9.0) and means were compared by the Tukey test at 5% probability. The initial average weight of animals was 204.8 kg; final weights were 260.9 and 276.9 kg for animals that received protein and protein+energy supplement, respectively. The forage availability, sward height and stocking rate values did not differ with supplementation, but they showed difference between the experimental periods. The average time spent grazing during daylight of animals fed protein+energy supplement was shorter as compared with those which consumed protein supplement. Animals kept under the same pasture conditions during the dry season show better performance when they receive protein+energy supplement than protein supplement.

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The comet assay has been described as an efficient tool for the detection of changes in the DNA molecule of cells exposed to contaminating agents in vivo and in vitro. The possible environmental contamination due to the persistence of chromium residues from tannery effluents was determined in the waters of the Córrego dos Bagres stream, Municipal district of Franca/SP, by the comet assay on CHO-K1 cells. Water samples were collected during the four seasons of the year 2001 at three distinct stations along the river. The data suggest that the comet test showed good sensitivity for the environmental monitoring of these waters and indicated that this test can be efficient for the determination of the quality of waters contaminated with effluents containing heavy metal residues such as chromium.

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Reasons for performing study: To our knowledge no studies evaluating risk factors to EIPH have been undertaken with such a population of horses in Brazil, which is one of the few countries in the racing community to accept the use of frusemide (FUR) as a prerace medication for bleeders. We also compared national results with those already in the literature. Objectives: To verify the influence of variables such as distance of the race, racetrack surface, going and season of the year in the recurrence and severity of EIPH and its effect on the finishing position of flat racing Thoroughbreds in Brazil. Methods: 2118 post race respiratory endoscopies were recorded, in a total of 1003 individual horses. All horses in the study were certified bleeders (deemed positive by registered veterinarians following one or more endoscopies) and were administered FUR prior to each race. Data was analysed using both ordinary logistic regression and multiple logistic regression. Results: The results suggest that race distance, season of the year and racetrack surface affect the recurrence of EIPH. Also, despite the use of FUR, the majority (62%) of horses continued to display some degree of haemorrhage. Conclusions: There was a tendency for horses that remained positive despite the use of FUR to finish unplaced in a race. Horses which had a significant reduction in bleeding and became HPIE negative after the use of FUR, tended to finish in top positions. It was not possible to determine a pattern of severity of EIPH in horses with more than one endoscopy. Further studies are required to improve our understanding of this syndrome and its correlations to performance in the racing Thoroughbred, together with the role of FUR and its possible enhancing performance effects and efficacy in consistently diminishing EIPH. Potential relevance: This study enabled a better understanding of the use of FUR in Brazilian Thoroughbred racehorses and showed there was a tendency towards improvement in performance after administrion of FUR in bleeders. The fact that a large number of horses remained positive for EIPH despite the use of FUR should encourage the scientific community to search for better ways of reducing, or preventing, this syndrome. © 2006 EVJ Ltd.

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The aim of the present study was to evaluate the effects of season of the year (summer and winter) and parity (heifers and cows) on oocyte quality and number in buffaloes. For this purpose, 71 buffaloes had follicular wave emergence synchronized before OPU. OPU of all follicles >= 2mm was done 5 days after the beginning of the hormonal protocol, in 4 replicates (two for each season). Data were analyzed by ANOVA using PROC GLIMMIX, in a 2 x 2 factorial arrangement of treatments. No interactions were observed in following variables: number of follicles, number of total and viable oocytes, recovery rate, percentage of viable oocytes, grade I oocytes, grade II oocytes, grade III oocytes, denuded oocytes, expanded cumulus oocytes, and atretic/degenerated oocytes. Number of follicles visualized at OPU and recovery rate were not affected by parity or season. Relative to parity, number of total and viable oocytes were greater in heifers than in cows, respectively. Concerning season of the year, number of viable oocytes and viable oocyte rate were increased in winter. In conclusion, better oocyte quality can be obtained from heifers and during winter in buffaloes. However, the number of total oocytes seems to be more influenced by parity than by season of the year in this species.

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In deserts, seedling emergence occurs only after precipitation threshold has been exceeded, however, the presence of trees modifies microenvironmental conditions that might affect the effectiveness of a water pulse. In the Monte desert, Prosopis flexuosa trees generate different micro-environmental conditions that might influence grass seedlings establishment. The objective of this work was: a) to know the effective minimum water input event that triggers the emergence of native perennial grass seedlings; b) to relate this fact with the effect of the shade of P. flexuosa canopy and the seasonal temperatures. Three important forage species of the Monte were studied: Pappophorum caespitosum and Trichloris crinita, with C4, and Jarava ichu, with C3 metabolism. Each season, seeds of these species were sown in pots placed at two light conditions: shade (similar to P. flexuosa cover) and open area, and with seven irrigation treatments (0, 10, 20, 30, 40, 2*10 and 3*10 mm). J. ichu did not emerge in any of the treatments. Significant seedling emergence was registered for P. caespitosum and T. crinita in shade conditions with 40 mm irrigation treatment in summer. Since 40 mm precipitation events are infrequent in the Monte, seedling emergence for these species would be restricted to exceptional rainy years. The facilitating effect of P. flexuosa shade would be important during the hot season.

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Russian gas industry: The current condition of the gas industry is one of the most crucial factors influencing the Russian state·s functioning, internal situation and international position. Not only is gas the principal energy resource in Russia, it also subsidises other sectors of the economy. Status of the main European gas exporter strengthens also Russia's importance in the international arena. New regional in-security: Ten years have passed since the Central Asian states declared their independence, but their relationship with Russia still remains close, and the latter treats them as its exclusive zone of influence. A crucial reason for keeping Central Asia within the orbit of Moscow·s influence is the fact that Russia exercises control over the most important transport routes out of the region of raw materials for the power industry, on which the economic development of Asia depends on. But this is the only manifestation of Central Asia·s economic dependence on Russia. Moscow lacks solid economic instruments (i.e. investment input or power industry dependence) to shape the situation in the region. Caspian oil and gas: Caspian stocks of energy resources are not, and most probably will not be, of any great significance on the world scale. Nevertheless it is the Caspian region which will have the opportunity to become an oil exporter which will reduce the dependence of the European countries on Arabian oil, and which will guarantee Russia the quantities of gas which are indispensable both for meeting its internal demands and for maintaining its current level of export. For Azerbaijan, Kazakhstan and Turkmenistan, the confirmation of the existence of successive oil strata is not only an opportunity to increase income, but also an additional bargaining chip in the game for the future of the whole region. The stake in this game is the opportunity to limit the economic, and by extension the political influences of Russia in the region.