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131.
132.
Comparison of methods for assessing the prevalence and extent of pneumonia in market weight Swine 总被引:2,自引:0,他引:2 下载免费PDF全文
Morrison RB Hilley HD Leman AD 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(12):381-384
The purpose of this study was to compare four different techniques that may be used to assess the prevalence or severity of enzootic pneumonia in a swine herd. These techniques included: 1) assessing the percentage of lung involved and calculating a mean percentage and standard deviation for each herd, 2) counting the number of lungs in the herd sample that have greater than a predetermined amount of pneumonia and calculating the prevalence of the sample thus affected, 3) scoring only the lung from each herd sample that was maximally affected by pneumonia, and 4) allocating lungs to categories depending on the approximate extent of pneumonia. Five hundred and sixty pigs from 41 different swine herds in southern Minnesota were examined at slaughter and lungs were evaluated for the extent of pneumonia that was macroscopically visible. 相似文献
133.
The aerobic aquatic metabolism of [14C]1,3-dichloropropene has been studied in two ditch waters and their associated sediments using a modification of the requirements of Section G.2. of the Dutch Registration Guidelines. Preliminary experiments showed that (a) the evaporation of 1,3-dichloropropene from water had a half-life of less than 5 h, and (b) in a soil/water slurry, 1,3-dichloropropene was rapidly converted to 3-chloropropenoic acid. In the definitive experiment conducted in two sediments, the overall recovery of radioactivity was good (84·5%) given the volatile nature of the chemical. In both sediment types, 1,3-dichloropropene evaporated rapidly from water. In the Letcombe samples (organic silty clay loam) more radioactivity was associated with the sediment (40%) than ditch water (5%) than in Marcham samples (medium clay, 12% in sediment and 10% in water) and this may reflect the organic matter content of the two sediments (10·5% and 2·9% respectively). The 1,3-dichloropropene in the ditch water was rapidly converted to 3-chloropropenoic acid and other minor polar products. The material in the soil was not investigated further. 相似文献
134.
Salt blocks containing 30 or 120 ppm selenium were tested as the sole supplement for sheep farmed in a selenium-deficient area of New Zealand (Te Anau). Both concentrations were unsatisfactory in preventing selenium deficiency. In five trials using 120 ppm Se salt, the highest percentages of sheep found to be deficient were 31% (lambs) and 32% (ewes). If sheep which were classed as marginally deficient were included these percentages became 63% (lambs) and 56% (ewes). Some instances of selenium-responsive unthriftiness in lambs were encountered, and in one trial there was the possibility of selenium-responsive infertility having contributed to the low lambing performance of the ewes. There was no evidence of white muscle disease. Selenium levels in the liver and kidney were well below the permitted maximum. Because selenised salt failed to eliminate selenium deficiency, its use as a sole supplement for sheep grazing selenium deficient pasture is not recommended. 相似文献
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Incorporating indigenous knowledge of fodder trees into small-scale silvopastoral systems in Jamaica 总被引:2,自引:0,他引:2
A study was conducted to identify and explore indigenous knowledge relating to fodder trees and silvopastoral management systems of small-scale farmers in seasonally dry areas of Jamaica. The objectives of the study were to: 1) explore farmers indigenous knowledge relating to fodder trees and silvopastoral management systems in a subtropical dry climate; 2) examine pastoral land-use systems and technologies in current use; and 3) seek to integrate this information into silvopastoral tree fodder systems. Data were gathered via observation and semistructured interviewing. A snowball sampling strategy was used to purposively select all small-scale farmers who had cattle in the Green Park valley for interview.Of forty farmers interviewed, 37 males (92.5%) and 3 females (7.5%) were primary caretakers of cattle. Twenty-seven of 40 farmers (68%) raised cattle to generate income. During extended droughts farmers are forced to look for alternatives to desiccated, overgrazed pasture grasses, including: 1) local travel to harvest sugar cane tops and to cut Guinea grass (Panicum maximum); 2) purchase of bag feed; and 3) harvest and use of tree fodder. Preferred fodder trees were identified as Bacedar (Guazama ulmifolia), Guango (Albizia saman), Breadnut (Brosimum alicastrum) and Quickstick (Gliricidia sepium).Recommended silvopastoral management systems include fodder hedgerows, three strata forage systems, and living fences. In addition, production of indigenous fodder tree species, introducing improved tree fodder species, and planting improved pasture grasses concurrent with cash trees is suggested. 相似文献
138.
The process of lesion formation and host response to natural infection by Armillaria ostoyae were studied in the roots of western larch (Larix occidentalis) and Douglas‐fir (Pseudotsuga menziesii ssp. glauca) trees in the three age classes, 6–8, 18–19 and 85–95 years. The characteristics of lesions on infected roots were recorded and bark samples were dissected from infection points and lesion margins in the field and stored in liquid nitrogen for macroscopic study in the laboratory. Infection in the roots of 6‐ to 8‐year‐old trees advanced freely, overcoming any host resistance, quickly girdling the root collar and killing the trees. In 18‐ and 19‐year‐old trees, however, 43% of infections on western larch and 27% of the infections on Douglas‐fir roots were confined to lesions bounded by necrophylactic periderms with multiple bands of phellem. Host response was similar in 85‐ to 95‐year‐old trees, but the percentage of confined lesions was higher than in younger trees. The results suggest that larch shows resistance to A. ostoyae at a younger age and with greater frequency than Douglas‐fir. 相似文献
139.
Morrison RN Koppang EO Hordvik I Nowak BF 《Veterinary immunology and immunopathology》2006,109(3-4):297-303
Amoebic gill disease (AGD) is characterised by the association of Neoparamoeba sp. with hyperplastic gill tissue of affected fishes, however, the identity and role of host cells associated with AGD lesions are not known. Here, we investigated cells with an immunological role that were associated with AGD lesions by locating cellular MHC class II β chain. A tank housing Atlantic salmon (Salmo salar) was inoculated with Neoparamoeba sp., and MHC class II β chain expression in the gills was qualitatively assessed by immunohistochemistry. In AGD-naïve control fish, MHC class II+ cells were detected basolateral to the interlamellar epithelium as well as upon the interlamellar and secondary epithelium. In the gills of AGD affected fish MHC class II+ cells were observed in both affected and unaffected tissue. Within AGD lesions, numerous MHC class II+ cells were present and these cells exhibited variable levels of expression suggesting that like mammals, MHC class II expression is highly regulated. The presence of MHC class II+ cells within gill lesions is indicative of immune cell trafficking and these cells could contribute in an antigen presentation capacity to the development of an antibody response in fish chronically affected by AGD. 相似文献
140.
Aono S Li C Zhang G Kemppainen RJ Gard J Lu W Hu X Schwartz DD Morrison EE Dykstra C Shi J 《Veterinary immunology and immunopathology》2006,113(1-2):181-190