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排序方式: 共有1161条查询结果,搜索用时 15 毫秒
961.
Basdani E Papazoglou LG Kazakos GM Bright RM 《Journal of the American Animal Hospital Association》2011,47(5):351-355
Four dogs were diagnosed with urethral catheter malfunction. The catheter was kinked in three dogs and knotted in one dog. In two dogs, kinking of the catheter was associated with presence of urethroliths in the perineal urethra. Diagnosis was based on the difficulty encountered retrieving the catheter in all dogs and swelling in the scrotal or perineal area in two dogs. Diagnosis of catheter kinking or knotting was confirmed after catheter retrieval. Catheter removal was achieved in two dogs after traction under anesthesia, whereas scrotal or perineal urethrotomy were used in the other two dogs. No complications associated with urination were reported in any of the dogs after 7 to 12 mo. 相似文献
962.
Respiratory neoplasms are rare in birds. This report describes carcinoma of the bronchial epithelium in a red-shouldered hawk (Buteo lineatus) that presented with weakness and lethargy lasting 4 days that progressed to seizures. Grossly, the caudal air sac and coelomic cavity contained approximately 15 ml of dark brown cloudy fluid that displaced the intestines cranially. Nodular plaques were present on the viscera and air sacs. Microscopic examination of tissues revealed a mass that expanded the bronchial lumen and was composed of papillary proliferations of rows of small cuboidal epithelial cells that were small and uniform in size with a low mitotic index. Metastases were present on the surfaces of caudal air sac, kidney, and multifocal peritoneal surfaces of the coelomic cavity. Clinical signs were most likely the result of West Nile virus infection, which was confirmed by immunohistochemistry of brain tissue. 相似文献
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964.
965.
Zhoumeng Lin Miao Li Yu-Shin Wang Lisa A. Tell Ronald E. Baynes Jennifer L. Davis Thomas W. Vickroy Jim E. Riviere 《Journal of veterinary pharmacology and therapeutics》2020,43(5):385-420
Physiologically based pharmacokinetic (PBPK) models for chemicals in food animals are a useful tool in estimating chemical tissue residues and withdrawal intervals. Physiological parameters such as organ weights and blood flows are an important component of a PBPK model. The objective of this study was to compile PBPK-related physiological parameter data in food animals, including cattle and swine. Comprehensive literature searches were performed in PubMed, Google Scholar, ScienceDirect, and ProQuest. Relevant literature was reviewed and tables of relevant parameters such as relative organ weights (% of body weight) and relative blood flows (% of cardiac output) were compiled for different production classes of cattle and swine. The mean and standard deviation of each parameter were calculated to characterize their variability and uncertainty and to allow investigators to conduct population PBPK analysis via Monte Carlo simulations. Regression equations using weight or age were created for parameters having sufficient data. These compiled data provide a comprehensive physiological parameter database for developing PBPK models of chemicals in cattle and swine to support animal-derived food safety assessment. This work also provides a basis to compile data in other food animal species, including goats, sheep, chickens, and turkeys. 相似文献
966.
Napoleón Vargas Jurado Larry A. Kuehn Ronald M. Lewis 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(4):365-373
Interest in reducing labour costs due to shearing has led to development of breed types that shed their wool naturally. Selection at young ages can facilitate response. Reliability of predictions of adult from lamb wool shedding (WS) is thus key in the design of breeding programmes to increase shedding. Our objectives were to estimate heritabilities and genetic relationships between WS measured once in lambs and repeatedly in ewes and to assess the accuracy of lamb WS EBV to predict ewe WS EBV based on a multi-trait threshold or a repeatability model. Data were 4,971 lamb and 3,335 ewe WS records on a Romanov, White Dorper and Katahdin composite flock. For the multivariate model, WS heritability ranged from 0.47 ± 0.03 in lambs to 0.59 ± 0.04 at 1 year of age. For the repeatability model, WS in adult ewes was moderately heritable (0.50 ± 0.03) and repeatable (0.60 ± 0.02). Genetic correlations were 0.72 ± 0.04, 0.65 ± 0.05, 0.50 ± 0.09 and 0.51 ± 0.09 between lamb WS and 1st through 4th record, respectively. Given the moderately high heritability and high correlations between WS performance in lambs and ewes, selecting animals early in life would effectively increase WS in crossbred flocks. 相似文献
967.
968.
The U.S. machine tool (MT) sector has undergone substantial restructuring over the past three decades. Despite signs of a commercial rebound in recent years, however, a number of critical issues remain for this industry. Not all firms share these concerns, in that differences exist between producers located in the core manufacturing belt and those located elsewhere. This paper examines the characteristics, competitive problems, and markets of firms located in these two regions. Survey data from a sample of 104 machine tool companies reveal that significant core–periphery differences exist with regard to firm–specific difficulties and markets served. The data also show that firms in the periphery have been growing significantly faster than firms in the core. The paper concludes with a discussion of the likely reasons for regional variability in the characteristics of firms in this industry. Directions for future research are also suggested, notably with regard to the interplay between national regulatory conditions and the competitive performance of MT firms. 相似文献
969.
Margaret A. Schwertner Kenneth K. M. Liu Frederic T. Barrows Ronald W. Hardy Faye M. Dong 《Journal of the World Aquaculture Society》2003,34(2):162-174
Four different methods of pelleting—extruded (EXT), steam pelleted (STM), using a Universal Pellet Cooker (UPC), and expanded (EXP)—were performed on subsamples of a single batch of mash to determine the effects on feed pellet characteristics, in vivo feed digestibility, and performance of rainbow trout Oncorhynchus mykiss fed the diets for 16 wk. Results indicated that the STM feed was the most (851 g/L) and UPC feed the least (672 g/L) dense, and that UPC feed had the highest % float (8.3%) and, of the pellets that sank, the fastest sink rate (15.1 cm/sec). While some differences occurred among pelleted diets in loss of dry matter (% dry loss) after incubation in a water bath for up to 10 min, the overall % dry loss was only approximately 1–2%. The method of pelleting did not affect fish weight gain, feed conversion ratio, or specific growth rate. Measurement of the apparent digestibility coefficient of dry matter of the test diets using Cr2 O3 as the marker ranged from 71–89%. While it appeared that the method of pelleting can affect feed characteristics and the amount of feed offered to the fish, fish performance was not affected. 相似文献
970.
Gary W Brester John M Marsh Ronald L Plain 《Veterinary Clinics of North America: Food Animal Practice》2003,19(2):493-518
The maturation of the US beef and pork markets and increasing consumer demands for convenience, safety, and nutrition suggests that the beef and pork industries must focus on product development and promotion. New marketing arrangements are developing that help coordinate production with consumer demands. The relative high levels of incomes in the United States are likely to increase the demands for branded products rather than increase total per capita consumption. Foreign markets represent the greatest opportunity for increased demand for commodity beef and pork products. Increasing incomes in developing countries will likely allow consumers to increase consumption of animal-source proteins. Real prices of beef and pork have declined substantially because of sagging domestic demand and increasing farm-level production technologies. Increasing US beef and pork exports have obviated some of the price declines. Pork attained a net export position from a quantity perspective in 1995. The United States continues to be a net importer of beef on a quantity basis but is close to becoming a net exporter in terms of value. By-products continue to play a critical role in determining the red meat trade balance and producer prices. The United States, however, must continue to become cost, price, and quality competitive with other suppliers and must secure additional market access if it is to sustain recent trade trends. Several trade tensions remain in the red meat industry. For example, mandated COOL will undoubtedly have domestic and international effects on the beef and pork sectors. Domestically, uncertainty regarding consumer demand responses or quality perceptions regarding product origin, as well as added processor-retailer costs will be nontrivial. How these factors balance out in terms of benefits versus costs to the industry is uncertain. From an international perspective, some beef and pork export suppliers to the United States could view required labeling as a trade restriction, which could ultimately impact future US red meat exports. Conversely, some countries may view such labeling requirements as an opportunity to brand high-quality products. The US lamb meat industry has experienced declining real prices, domestic production, and demand. The cessation of wool incentive payments, increased environmental regulations, and competition by imports have significantly affected the industry. Import suppliers have capitalized on product quality in this niche market. Trade restrictions initially imposed in 1999 by the US Government were ruled illegal by the WTO. The US Government responded by providing financial assistance to lamb producers. Product quality improvements and promotion aimed at the domestic market, however, will be critical factors in shaping the economic viability of the US lamb meat industry. 相似文献