共查询到20条相似文献,搜索用时 890 毫秒
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《畜牧兽医科技信息》2004,(9)
根据新《兽药管理条例》的规定,自2004年11月1日起,各省级兽医行政管理部门不得继续审批新兽药、发布地方标准和核发兽药产品批准文号。为此,农业部将组织有关专家,开展针对2004年11月1日前发布的兽药地方标准的清理工作。具体将分两个阶段进行,第一阶段,审查2004年6月底前发布的地方标准,申报截止时间为2004年9月底;第二阶段,审查2004年7~10月底期间发布的地方标准,申报截止时间为2005年1月底。农业部将开展兽药地方标准的清理 相似文献
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当前兽药地方标准清理工作已进入攻关阶段,但在清理地方标准的实际工作中尚存在一些问题,笔者分析了这些具体问题,认为在升标工作中,政府应当给予合理的政策扶持,加快地方标准清理工作进度,保护企业利益;企业应当着重做好品种筛选,合理安排临床试验资金投入;企业通过采取联合参与升标方式,减少资金投入;对于移植外省标准,可采取不同措施妥善解决;为保证升标工作顺利进行,农业部和各省兽医行政管理部门应做好升标培训指导工作. 相似文献
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R.J. Scholes 《African Journal of Range and Forage Science》2013,30(3):147-151
The recovery of cleared Colophospermum mopane thicket in the eastern Transvaal lowveld, to a level where its effect on grass production is similar to that in the pre‐cleared state, occurs within fourteen years. Based on certain assumptions, the ‘effective duration’ of the increase in grass production after clearing is about half of the recovery period. A model describing the recovery of basal area with time since clearing is presented. Simulations show that the recovery period is shortened by higher rainfall and lengthened by drought. It is hardly affected by the degree of clearing mortality typically achieved by the use of hormonal herbicides, but is extended to twenty‐two years if 90% mortality is achieved. Complete clearing mortality and a seedling establishment rate of four seedlings/ha/yearresults in recovery within forty years. 相似文献
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《African Zoology》2013,48(2):228-239
Spatial and temporal patterns of disturbance and the subsequent heterogeneity are critical in maintaining biodiversity within grassland ecosystems. Grassland birds have evolved within this ‘shifting mosaic’ to become reliant on specific habitat characteristics maintained under varying levels of both natural and anthropogenic disturbance. Unfortunately, grasslands in South Africa have been extensively transformed and remain poorly conserved, threatening grassland avifauna. Mistbelt grassland is a threatened vegetation type endemic to the province of KwaZulu-Natal, of which only 0.3% is formally protected. This study investigated seasonal and patch type heterogeneity in a Mistbelt grassland avian community by determining avian community structure and composition in four patch types, i.e. i) untransformed open grassland, ii) burnt grassland, iii) bramble-invaded and, iv) bramble-cleared grassland, during winter and summer. Avian assemblages were significantly different between the different patch types for each season. The bramble patch type negatively affected grassland bird species diversity. Bramble-cleared grassland and untransformed grassland had similar vegetation structure and avian communities in the summer, suggesting that the grassland bird community benefitted soon after the clearing of invasive vegetation. This study provides further evidence that bird diversity is enhanced in structurally heterogeneous grassland landscapes. Furthermore, the protection and appropriate management of privately owned Mistbelt grassland, conserved in the form of rangeland, is an important refuge for threatened and endemic avifauna, such as the globally-threatened blue swallow (Hirundo atrocaerulea) and wattled crane (Bugeranus carunculatus). 相似文献
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Nutritive composition of diets and forage intake of goats utilizing pastures of cleared, two levels of thinned (25% and 55% canopy cover) and undisturbed (control) tropical woodland were compared on a seasonal basis. Esophageally fistulated goats were used to collect dietary samples for chemical analysis. Total fecal collections were used to estimate organic matter intake (OMI) and digestible energy intake (DEI). Forage availability during the wet season was more than threefold higher (P less than .1) on treated than on control pastures. Although available forage was similar (P greater than .1) for all treatments by the middle of the dry season, available forage on the control pastures was limited mostly to dry tree leaves. Goats selected diets 4% higher (P less than .1) in neutral detergent fiber on the control pastures than on the treated pastures; otherwise, diets selected by the goats on the various pastures were similar in terms of crude protein, lignin and in vitro organic matter digestibility. However, OMI and DEI were 23 and 31% higher (P less than .1), respectively, on the treated pastures than on the control pastures. There were no differences among the cleared and thinned treatments. Excessively wet conditions during the rainy season adversely affected goat performance. High populations of biting insects and wet field conditions reduced foraging time and diet selection. The generally higher levels of available forage on the cleared and thinned pastures did not result in the goats' selecting diets higher in nutritive value on the treated pastures than on the control pastures. Instead, the increased forage availability for the treated pastures allowed the goats to attain higher intake of forage. 相似文献