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1.
龙骨损伤是福利和健康受损的主要表现之一.文章从蛋鸡生产的角度出发,阐述了蛋鸡龙骨损伤的概况、蛋鸡龙骨损伤的研究现状及其对蛋鸡福利状况的影响,旨在呼吁重视蛋鸡龙骨损伤现象,促进蛋鸡产业的健康可持续发展.  相似文献   
2.
在对玻璃钢渔船舭龙骨连接形式调查研究的基础上,根据舭龙骨在水中所起到的阻尼作用,计算渔船舭龙骨板所爱的应力;并根据4种玻璃钢骨架的剥离试验数据,计算出玻璃钢渔船舭龙骨的连接强度。将计算结果与试验结果相比,选出了适合不同玻璃钢渔船的舭龙骨连接形式。  相似文献   
3.
Feather pecking is still a behavioral problem in laying hen flocks, resulting in impaired welfare and economic losses. Environment enrichment, e.g., providing access to litter, to increase foraging behavior in laying hens has been shown to decrease feather pecking. This study investigated the effect of spreading crushed mussel shells (particle size 10 to 20 mm) in the litter area as an environment enrichment and source of calcium for layers receiving a commercial feed and for layers given a feed with 40% less calcium. These treatments were compared with a control involving hens given the commercial feed, but no mussel shells in the litter. The study included 900 Dekalb White layers housed in a single-tier floor system during a production cycle (20 to 72 wk of age). The mussel shells were consumed to a lower extent than predicted, resulting in calcium deficiency in hens fed the low-calcium diet. This in turn was evident as increased degree of keel bone deviations and lower eggshell breaking strength. Daily addition of crushed mussel shells to the litter for laying hens on a balanced or calcium-deficient diets did not generate any positive effects on bird feather cover, eggshell quality, production performance, or fearfulness. Hence, with the particle size of mussel shells used in this study, there was no indication of improved welfare due to environment enrichment.  相似文献   
4.
以高等级竞赛用体育木地板为研究对象,采用测定体育木地板主要功能指标的方法,研究不同龙骨参数的体育木地板结构性能,建立体育木地板龙骨结构(截面尺寸、间距)与冲击吸收率(Fr)、标准垂直变形(Vd)和球反弹率(Br)之间的一次回归方程,分析提出较优的龙骨设计参数。结果表明:龙骨参数对试验指标均有显著影响,显著性水平均为0.05及以上,综合分析各功能指标与试验因素水平组合,得出较优的龙骨设计参数为截面尺寸50mm×50mm、龙骨间距500mm×500mm。该研究填补体育木地板龙骨结构与主要性能指标间一次回归统计关系的空白,建立的统计方程可在理论统计范畴内指导体育木地板中龙骨结构设计及施工技术,为体育木地板龙骨的生产提供科学依据。  相似文献   
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6.
1. Selected health and welfare variables of laying hens from 79 flocks kept in alternative husbandry systems were assessed at the end of lay.

2. Investigations were carried out on 100 hens per flock at the slaughter line and recorded as part of a novel scoring system. In addition, post-mortem investigations as well as parasitological examinations were conducted on 10 birds from each flock.

3. Birds with access to free range had better plumage than birds kept in barn systems. Housing in aviaries was associated with a higher prevalence of foot pad lesions and keel bone deformations. In addition, poorer plumage, more and worse skin and foot pad lesions were documented in hens slaughtered during the winter months.

4. Oophoritis and/or salpingitis were the most prevalent pathomorphological changes observed. Intestinal parasites, especially Heterakis gallinarum and Ascaridia galli, were frequent. Hens kept indoors had fewer nematoda and cestoda than those from conventional and organic free range.

5. The slaughterhouse protocol allowed direct comparison of variables between flocks and specific problems to be identified in particular flocks. The results could be used to initiate detailed investigations into problematic issues on selected farms.  相似文献   

7.
鸡胸软骨硫酸软骨素的提取及分离纯化   总被引:4,自引:0,他引:4  
为优化硫酸软骨素的提取工艺和初步分析其结构,采用中心组合设计和响应面分析优化鸡胸软骨硫酸软骨素的酶法提取工艺,三氯乙酸除蛋白质、乙醇沉淀以及柱色谱精细纯化得到高纯度硫酸软骨素,并采用高效凝胶过滤色谱判定其纯度,红外光谱和核磁共振初步分析其结构。结果表明,硫酸软骨素的最佳提取工艺参数为温度55.68℃,pH值为6.40,时间为3.85 h,葡萄糖醛酸和硫酸软骨素提取率分别达到9.82%和28.05%。高效凝胶过滤色谱分析其纯度为99.01%。红外光谱和核磁共振显示硫酸软骨素主要是4硫酸化软骨素。  相似文献   
8.
郑芳 《北方园艺》2007,(11):156-160
通过对天脊山国家级地质公园植被状况的调查,对珍稀树种、古树、乡土树种、特产树种作了分类介绍.  相似文献   
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10.
ObjectiveInvestigate the effects of administration of meloxicam and carprofen on the mobility of hens with and without keel fractures.Study designWithin each of two experiments a ‘blinded’ randomised cross over design whereby birds received either the test drug (carprofen or meloxicam) or saline.AnimalsTwo groups of Lohman Brown hens with and without keel bone fractures.MethodsThe first group (n = 63) was treated with carprofen 25 mg kg−1 and saline subcutaneously, twice. The second group (n = 40) was treated with meloxicam (5 mg kg−1) and saline subcutaneously. The latency of birds to fly down from perches 50, 100 and 150 cm above the ground was measured after each treatment. Data from experiment 1 and 2 were analysed separately; the effects of drug treatment compared with saline on landing time for birds with and without keel bone fractures were evaluated using MLwiN.ResultsIn both experiments latency to fly down from perches was longer in hens with keel fractures and there was a significant interaction between perch height and fracture status. For carprofen, at the 50 cm, 100 cm and 150 cm perch heights, birds with fractures took (mean ± SD) 2.5 ± 2.9, 6.8 ± 9.7 and 11.5 ± 13.2 seconds respectively to fly down compared with 1.3 ± 0.5, 2.3 ± 1.2 and 4.2 ± 3.1 seconds for birds without fractures. For meloxicam, at the 50 cm, 100 cm and 150 cm perch heights, birds with fractures took 2.9 ± 2.5, 49.8 ± 85.4 and 100.3 ± 123.6 seconds respectively compared with 0.7 ± 0.5, 2.5 ± 7.1 and 3.0 ± 4.6 seconds to fly down for birds without fractures. There was no significant effect of carprofen or meloxicam treatment.Conclusion and clinical relevanceThese data provide further confirmation that keel fractures reduce the willingness of birds to move from perches.  相似文献   
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