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51.
52.
Objective: To investigate the relative efficacy and safety of the anthelmintic naphthalophos in sheep, either given alone or in combination with benzimidazole (fenbendazole and albendazole) or levamisole anthelmintics.
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option. 相似文献
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option. 相似文献
53.
Cattle in two herds developed signs of bloating, increased salivation and lacrimation, depression, respiratory distress, ataxia, and death after ingestion of hay that contained large amounts of poison hemlock (Conium maculatum). Twenty of 30 Angus cows and calves were affected in the first herd (2 died). In the second herd, 5 of 30 Holstein heifers were affected (1 died). The Conium alkaloids, coniine and gamma-coniceine, were quantified in the hay, the plants from the responsible hayfield, and the urine of affected animals. 相似文献
54.
The authors investigate counter-urbanization and population change in Georgia between 1960 and 1980 by examining commuting patterns. "The immediate objective is to construct the entire set of commuting fields of both large metropolitan areas to metropolitan and nonmetropolitan employment centers. We then proceed to the relationship between commuting from nonmetropolitan areas to all levels of Georgia's urban hierarchy and population change in these nonmetropolitan settings. By matching population growth and decline areas with explicit employment ties...the nature of the population changes is much better understood." Data from the 1960, 1970, and 1980 censuses for 581 Census County Divisions (CCDs) in Georgia are analyzed. It is concluded that "most nonmetropolitan growth taking place in Georgia is associated with intensification of metropolitan commuting fields along with growth of nonmetropolitan centers and their influence along the very periphery of metropolitan spheres of employment influence. However, a significant share of Georgia's nonmetropolitan population revitalization is explained by growth independent of direct metropolitan influence. It would appear then that nonmetropolitan growth centers are an important part of the basis for population decentralization in Georgia. Metropolitan spill-over alone cannot account for counterurbanization on this portion of the American economic landscape." 相似文献
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P.F. Fisher 《Geoderma》1983,29(2):93-105
The properties of soils associated with the Bronze Age site near the South Lodge of Rushmore Park, Wiltshire, are described. Three primary soil types are identified: rendzinas (Rendolls), argillic brown earths (Hapludalfs) and a brown calcareous earth (Eutrochrept). The mapped distribution of these soil types is related to the archaeological landscape. The argillic brown earths are limited in extent to the deeper soils of the positive (accumulating) lynchets of the field system, whereas rendzinas occupy the negative (eroding) lynchets and the remainder of the fields. The only occurrence of a brown calcareous earth is in a positive lynchet within the enclosure. From the distribution of soil types and analogies with the soils of other prehistoric field systems on the Chalk, it is concluded that the argillic brown earths have formed from a highly calcareous colluvial deposit since abandonment of the field system in the later Bronze Age. Further, the development of this soil type appears to be controlled by lateral throughflow of soil water combined with the re-establishment of a wooded landscape. Formation of the argillic brown earth at this site appears to be more recent than at any other site in southern England for which information has been published. 相似文献
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Fisher LW 《Science (New York, N.Y.)》1936,84(2189):534-535
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