哈纳斯自然保护区植被特点及植物区系形成的探讨

哈纳斯自然保护区的植被充分反映了欧洲－西伯利亚区系成分的特色。山地针叶林带与天山相比显著下降，为阴暗泰加林类型。植被类型丰富多样，与天山的植被特点迥然不同。本区植物区系形成于第四纪。其区系组成以温带成分为主，并含有少量的古地中海成分。以本土发生的安哥拉区系成分米体；发源于华夏地区的亚洲温带成分渗透至本区；残存的古地中海成分有小部分通过相邻地区向本区渗放。     

Protective effects of oral microencapsulated Mycoplasma hyopneumoniae vaccine prepared by co-spray drying method

The efficacy of Mycoplasma hyopneumoniae oral vaccine was investigated in microsphere dosage form. A co-spray drying process was used to apply an encapsulating material, Eudragit L30 D-55, to microspheres containing Mycoplasma hyopneumoniae antigens. The microspheres were generally effective (>93%) with protein release at pH 7.4, but almost none were released at pH 1.2, for 3 hr in an in vitro dissolution test. An SPF-swine model was used to evaluate the effectiveness of the microspheres as an oral vaccine, and the related immune responses. The serum's systemic IgG against M. hyopneumoniae was evoked by ELISA analysis, after a 2nd immunization of all pigs. The vaccinated groups' mean lesion score was significantly lower after the Mycoplasma hyopneumoniae challenge than that of the nonvaccinated/challenged groups (P<0.05). This study strongly suggests that the oral microspheres vaccine prepared by a co-spray drying method can provide effective protection against M. hyopneumoniae infection in pigs.     

In vivo and in vitro comparisons of spray-drying and solvent- evaporation preparation of microencapsulated Mycoplasma hyopneumoniae for use as an orally administered vaccine for pigs

OBJECTIVE: To evaluate the efficacy of an orally administered vaccine of Mycoplasma hyopneumoniae that was prepared by spray drying or solvent evaporation. ANIMALS: Thirty 6-week-old, crossbred, specific-pathogen-free (SPF) pigs. PROCEDURE: Pigs were randomly allocated into 5 groups and housed in an SPF facility. Pigs in 2 groups (groups AQ and CAP) were fed M hyopneumoniae enteric-coated vaccine on days 0, 10, and 20. A third group (group IM) received an IM injection of M hyopneumoniae vaccine with aluminium hydroxide as an adjuvant on days 0, 10, and 20. The last 2 groups (non-vaccinated-challenged [NV-C] and nonchallenged [NC]) were fed a sham treatment. All 24 pigs in groups AQ, CAFP IM, and NV-C were challenge exposed with 5 ml of a 10% pneumonic lung suspension administered on day 40 via intubation of the trachea. All pigs were slaughtered and the lungs removed and examined for lesions on day 68. RESULTS: In vitro studies indicated that these 2 microencapsulation techniques formed an effective shell and protected mycoplasmal antigen from gastric acid. Results of inoculation and challenge tests indicated that microencapsulated M hyopneumoniae were sufficiently potent to induce an immune response and provide good protection. CONCLUSIONS AND CLINICAL RELEVANCE: Orally administered microencapsulated M hyopneumoniae vaccines induced an immune response and reduced the severity of lung lesions in challenge-exposed pigs. Results suggest that this novel method can be applied to other antigens, because the spray-drying process yielded an orally administered M hyopneumoniae vaccine that induced a good immune response.     

中国肉类消费全景图和大趋势

中国食物消费进入新阶段,口粮消费下降,以肉为主的动物性产品消费量的增加是未来消费的主要趋势。本文描绘中国肉类消费全景图,并展望我国肉类消费的大趋势。分析认为,我国城镇居民肉类消费仍处在稳步增长阶段,农村居民肉类消费还有成倍增长的空间。     

隐性白羽鸡体重生长规律的研究

以两种代谢能、三种粗蛋白水平组成的6种日粮饲喂7～12周龄隐性白羽鸡,个体测定各周龄体重,进行生长分析,旨在研究有关因素对体重的影响。研究结果表明:①性别对2～12周龄体重、成熟体重估计值、初生重估计值、生长高峰周龄、高峰体重有极显著影响(P<0.01),均表现为公鸡大于母鸡,对生长速率参数的影响显著(P<0.05),表现为母鸡大于公鸡;②日粮能量对12周龄体重和生长速度参数有显著影响(P<0.05);③日粮蛋白对8～12各周龄体重、成熟体重估计值、高峰体重有显著影响(P<0.05);④1～6周龄体重遗传力为0.43～0.57,7～12周龄遗传模型1(0.37～0.67)比遗传模型2(0.33～0.58)估计的体重遗传力要高,成熟体重估计值、初生重估计值、生长速率参数、生长高峰周龄、高峰体重的遗传力分别为0.1、0.39、0.15、0.33、0.04。     

太湖鸡资源群体遗传变异的检测

应用微卫星标记对江苏省无锡市祖代鸡场有限公司太湖鸡的保种群体进行了遗传变异的分析,计算了群体的杂和度(H)和多态信息含量(PIC)。研究结果表明:30个微卫星标记在太湖鸡保种群体的杂和度为0.504～0.858之间,平均杂和度为0.688,群体的遗传多样性丰富;其中24个微卫星标记在太湖鸡中多态信息含量为高度多态,可作为有效遗传标记用于太湖鸡保种群的遗传分析,而且各座位杂和度的高低与PIC值的大小体现了较高的一致性。本研究结果为太湖鸡开发利用研究提供了基础,也为太湖鸡的合理保护提供了科学根据。     

大豆锈病研究现状与进展

大豆锈病近年在东南亚、南美洲发展迅速,对大豆生产威胁越来越大,尤其2004年11月登陆美国大陆,更引起大豆研究者、大豆生产国和进口国的极大关注。本文介绍了近年国际上大豆锈病的研究进展,主要包括大豆锈病的发现、地理分布、病原、症状、寄主范围、病原菌生理分化和防治技术研究等。     

不同培养基对香菇菌丝体酯酶同工酶的影响

本文应用垂直板聚丙烯酰胺凝胶电泳,对在不同培养基上生长的香菇菌丝体进行酯酶同工酶分析。结果表明,不同培养基会导致香菇菌丝体酯酶同工酶酶谱产生差异。     

Gross Anatomy of the Pancreatic Lobes and Ducts in Six Breeds of Domestic Ducks and Six Species of Wild Ducks in China

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the ‘first pancreatic duct’(Ducius pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.     

双峰驼精清及其活性组分凝集素寡糖的初步研究

应用植物血凝素与寡糖结构相同或相似的糖复合物专一凝集的原理与方法,结合小鼠排卵试验,间接观察了公驼精清及其经ＤＥ－５２离子交换层析和高效液相层析提取分离的活性组分的蛋白组成。结果表明,公驼精清内糖蛋白含有２种以上的寡糖,其内的活性组分及诱导排卵因子与所试植物血凝素不发生反应