饲粮非植酸磷水平对39~46周龄黄羽肉种母鸡繁殖性能、胫骨指标和血浆生化指标的影响

本试验旨在研究不同非植酸磷( NPP)水平对39~46周龄黄羽肉鸡父母代种鸡繁殖性能、胫骨指标和血浆生化指标的影响,探讨该阶段适宜磷供给量。试验选用39周龄岭南黄羽肉鸡父母代种母鸡810只,根据体重和产蛋率分为5个组,每组6个重复,每重复27只鸡。组1为对照组,饲喂玉米-豆粕型基础饲粮( NPP水平为0.30%),组2、3、4和5饲粮分别在基础饲粮中添加不同水平的磷酸氢钙,使饲粮NPP水平分别为0.35%、0.40%、0.45%和0.50%,其他营养成分各组基本一致。试鸡限饲122 g/(只·d),自由饮水。试验期8周。结果表明：1)试验期内, NPP水平未显著影响试鸡平均日增重、平均日产蛋量、料蛋比、平均蛋重和破蛋率(P>0.05),显著影响了产蛋率和不合格蛋率(P<0.05),0.45%组产蛋率显著高于0.30%和0.40%组(P<0.05),0.40%组不合格蛋率显著低于其余4组(P<0.05)。2)饲粮 NPP水平显著影响了试鸡39~40周龄种蛋长径、蛋短径、蛋形指数和蛋壳强度(P<0.05),显著影响了45~46周龄种蛋蛋壳强度( P<0.05)。3) NPP水平对种蛋孵化性能(受精率、孵化率、健雏率、健雏平均出壳重)无显著影响(P>0.05)。4)饲粮 NPP 水平显著增加了试鸡脱脂胫骨粗灰分中钙、磷含量(P<0.05)。5)0.40%和0.45%NPP组试鸡血浆甲状旁腺激素含量显著高于0.30%和0.35%组( P<0.05),0.50%组血浆降钙素含量显著高于其余4组( P<0.05)。综上,39~46周龄黄羽肉鸡父母代种母鸡饲粮NPP适宜水平为0.40%~0.45%,根据采食量计算得到每日NPP需要量为0.488~0.549 g。     

“花间隐榭，水际安亭”——基于华南植物园水榭和桂林芦笛岩水榭的营境分析

华南植物园水榭和桂林芦笛岩水榭是20世纪七八十年代岭南园林建筑的两处经典作品。它们与明代造园专著《园冶》里"花间隐榭,水际安亭"的字句遥相呼应,以现代主义建筑的创作风格构造出中国传统山水居游的惬意情境。以这两个经典现代风景建筑为例,尝试从情境、场景和身体体验3个不同角度,具体探讨风景建筑的营境操作。情境旨在针对建筑总体布局进行分析;场景则着眼于空间组合的探讨;最后从身体体验出发,讨论建筑的细部设计。     

广州近代城市公园的中西合璧特征探析

广州近代城市公园设计精巧,风格独特,在岭南造园史上具有重要地位。结合历史图文资料,运用风景园林史学和风景园林美学相结合的研究方法,归纳分析其造园特征。广州近代城市公园的中西合璧特征主要体现在3个方面:因地制宜的空间布局、中西融合的建筑小品、多姿多彩的植物景观。探析其中西合璧特征,有利于丰富岭南近代园林历史与理论研究,推进对广州近代城市公园的保护与造园智慧的传承。     

南粤古驿道保护修复工程做法研究

针对近几年广东省在南粤古驿道保护修复工程做法方面取得的实践工作经验,总结了南粤古驿道分类及分级,南粤古驿道用材区域概述、保护与修复原则、修复程序、典型古驿道修复做法、修复施工要求等内容。通过梳理修复工程方法,规范其修复技术步骤及施工标准,防止建设性的破坏,再现历史工艺。     

山羊卵母细胞体外成熟体系研究进展

卵母细胞体外成熟(IVM)是山羊胚胎体外生产的关键步骤,其对山羊体外生产胚胎的数量和质量均具有非常重要的意义。此外,IVM还可以满足胚胎工程技术如体细胞核移植、转基因动物生产对卵母细胞的大量需求。然而,由于山羊卵母细胞体外成熟研究起步较晚,与牛、猪等家畜相比仍然存在不小的差距,存在诸如体外成熟率低、胚胎质量不佳、培养体系可重复性低等问题。因此,分析山羊卵母细胞体外成熟的主要影响因素,提高山羊卵母细胞体外成熟率,建立山羊卵母细胞体外成熟稳定培养体系,就成为了近年来山羊胚胎体外生产的研究重点。论文综合国内外学者近年的相关研究,对可能影响山羊卵母细胞体外成熟效率的各种因素进行了综述分析,同时对山羊卵母细胞体外成熟现存问题进行了分析,以期为建立山羊卵母细胞体外成熟体系提供理论支持。     

四川省部分地区山羊沙门氏菌健康带菌率及耐药性调查

为了解四川省山羊沙门氏菌带菌情况,本试验采集了四川省部分地区5个规模化山羊养殖场表观健康山羊粪便196份,经BPW预增菌、TTB选择性增菌后,采用靶向invA基因的PCR方法检测沙门氏菌的带菌率;对阳性样本进行细菌分离鉴定,随机选择25株沙门氏菌分离株测定其对15种抗菌药物的敏感性。结果显示,山羊沙门氏菌的平均带菌率为54.59%。药敏试验结果显示,分离株均对丁胺卡那敏感,而对其余14种抗菌药物呈不同程度的耐药,多重耐药菌株占88%,其中耐2~7种药物的占52%,耐9~13种药物的占36%。结果表明,四川省部分地区山羊的沙门氏菌健康带菌率较高,且多重耐药性普遍,其公共卫生意义值得进一步研究。     

扶正解毒散及其超微粉体外抗鸡传染性法氏囊病病毒药效比较

采用鸡胚法和细胞法2种体外抗病毒试验比较扶正解毒超微粉(FZSM)和扶正解毒散(FZ)的抗鸡传染性法氏囊病病毒(IBDV)效果。鸡胚法:在FZSM和FZ 2种煎煮液对鸡胚安全浓度范围内分别选取3个浓度,采用先加煎煮液后接种病毒和先接种病毒后加煎煮液2种方式,接种10日龄SPF鸡胚,测定2种煎煮液对IBDV ELD50的影响。细胞法:在FZSM和FZ 2种煎煮液对鸡胚成纤维细胞(CEF)安全浓度范围内分别选取3个浓度,采用先加煎煮液后接种病毒和先接种病毒后加煎煮液2种方式,加入到长成单层的CEF中继续培养,观察并统计各孔的细胞病变(CPE)。结果显示,FZSM和FZ 2种煎煮液均可以降低IBDV的病毒滴度和CPE抑制率,高浓度效果优于低浓度;同浓度FZSM效果优于FZ;预防作用效果优于治疗作用效果。结果表明FZSM和FZ均具有体外抗IBDV的作用,且FZSM效果优于FZ。     

The Potential of Mesenchymal Stem Cell in Prion Research

Scrapie and bovine spongiform encephalopathy are fatal neurodegenerative diseases caused by the accumulation of a misfolded protein (PrP^res), the pathological form of the cellular prion protein (PrP^C). For the last decades, prion research has greatly progressed, but many questions need to be solved about prion replication mechanisms, cell toxicity, differences in genetic susceptibility, species barrier or the nature of prion strains. These studies can be developed in murine models of transmissible spongiform encephalopathies, although development of cell models for prion replication and sample titration could reduce economic and timing costs and also serve for basic research and treatment testing. Some murine cell lines can replicate scrapie strains previously adapted in mice and very few show the toxic effects of prion accumulation. Brain cell primary cultures can be more accurate models but are difficult to develop in naturally susceptible species like humans or domestic ruminants. Stem cells can be differentiated into neuron‐like cells and be infected by prions. However, the use of embryo stem cells causes ethical problems in humans. Mesenchymal stem cells (MSCs) can be isolated from many adult tissues, including bone marrow, adipose tissue or even peripheral blood. These cells differentiate into neuronal cells, express PrP^C and can be infected by prions in vitro. In addition, in the last years, these cells are being used to develop therapies for many diseases, including neurodegenerative diseases. We review here the use of cell models in prion research with a special interest in the potential use of MSCs.     

The face of conservation responding to a dynamically changing world

In its 40‐year history, the science of conservation has faced unprecedented challenges in terms of environmental damage and rapid global change, and environmental problems are only increasing as greater demands are placed on limited natural resources. Conservation science has been adapting to keep pace with these changes. Here, we highlight contemporary and emerging trends and innovations in conservation science that we believe represent the most effective responses to biodiversity threats. We focus on specific areas where conservation science has had to adjust its approach to address emerging threats to biodiversity, including habitat destruction and degradation, climate change, declining populations and invasive species. We also document changes in attitudes, norms and practices among conservation scientists. A key component to success is engaging and maintaining public support for conservation, which can be facilitated through the use of technology. These recent trends in conservation and management are innovative and will assist in optimizing conservation strategies, increasing our leverage with the general public and tackling our current environmental challenges.     

森林人家休闲健康旅游发展对策

从创新休闲模式,提升产业结构的理念出发,提出发展森林人家亟待解决的问题和对策。