The potential of temporary shelters to increase survival of the endangered Mexican axolotl

1. Amphibian populations worldwide are in decline. Proactive conservation techniques such as translocations into created and restored wetlands have gained popularity in recent years but may fail owing to high predation and low environmental adaptability.
2. The Mexican axolotl (Ambystoma mexicanum), affected by rapid urbanization, is now possibly extinct in the wild despite millions living in captivity throughout the world.
3. The aim of this study was to explore whether ponds from an artificial wetland can function as temporary shelters for a viable population of axolotls that could be re-introduced into their native ecosystem in Xochimilco once it is restored.
4. Egg-laying and hatching of 11 unique axolotl pairs placed into reproductive enclosures and larval survival to 7 weeks and up to 12 months were examined. Physicochemical and biological parameters were estimated and compared among ponds.
5. The results from this study are encouraging as they suggest that two ponds have adequate conditions for axolotls to reproduce and for larvae and juveniles to survive.

     

不同品种苜蓿在不同生育期总皂苷含量变化的研究

通过分析内蒙古地区种植的紫花苜蓿、黄花苜蓿、草原2号苜蓿在不同生育期总皂苷含量的变化,并利用SPSS11．5统计软件进行方差分析,并采用Duncan法进行均值的多重比较。结果表明,返青期到初花期的植株总皂苷含量为紫花苜蓿〉草原2号苜蓿〉黄花苜蓿,紫花苜蓿的总皂苷含量极显著高于黄花苜蓿（P〈0．01）;在盛花期和结荚期,草原2号苜蓿的总皂苷含量高于其他2个品种;成熟期黄花苜蓿的总皂苷含量最高。紫花苜蓿与草原2号苜蓿在结荚期的植株总皂苷含量显著大于其他生育期（P〈0．05）,黄花苜蓿的总皂苷含量在盛花期达到最大。     

应用PCR技术检测鹅细小病毒

根据鹅细小病毒GPVH1株结构蛋白VP1与VP3编码基因非重叠核苷酸序列设计了一对引物GPR1 /GPR2 ,用这对引物对感染器官内的GPR和接种鹅胚增殖的GPV进行PCR扩增 ,其结果引物GRP1 /GPR2能特异性地扩增GPVVP1 VP3区段核苷酸序列 ,扩增出与设计核苷酸片段大小相符的 0 6kb的序列 ,而对照的鹅副粘病毒cDNA及鸭瘟病毒 (DPR)DNA对照组均出现阴性结果。     

添加苯二氮化合物F89对皖西白鹅生长和代谢性能的影响

利用生理调节剂Ｆ８９提高皖西白鹅的摄食量,加速动物生长。日粮中添加２ｍｇ／ｋｇＦ８９,连续饲喂８～３５日龄皖西白鹅,日摄食量较对照组增加６．０２％,增重提高９．４０％,耗料比下降２．８９％。对育肥期鹅的增重也有明显影响。血液代谢物分析表明：饲喂Ｆ８９后,皖西白鹅血清中葡萄糖和尿酸浓度下降,β－脂蛋白浓度上升。提示Ｆ８９不仅能促进鹅的摄食量,而且可以影响鹅的代谢机能,促进生长     

基于B/S结构的家蚕育种与种性维持信息管理系统

对家蚕育种亲本及其新品种性状数据档案实行信息化管理,可在家蚕育种和品种的种性维持过程中自动实现完整的信息采集、计算、调用、选择等功能。开发了一个基于B/S结构的家蚕育种与种性维持信息管理系统,主要包括品种管理、计划任务管理、饲育信息管理、蚕茧信息管理、选种信息管理、选优信息管理等功能模块。选种信息管理模块的运行过程是通过电子天平称量蚕茧质量,然后根据计算模型自动进行数据信息处理与统计分析实施选择。用户可以方便地通过网络访问该系统,实现家蚕新品种选育及种性维持工作的自动化。     

中蜂越夏及秋季繁殖试验

在贵州锦屏进行的中蜂越夏及秋繁试验表明，４框以上的群势越夏较为安全。越夏期间每框足蜂约需补喂白糖１．５公斤。越夏后，蜂群群势约下降１／３左右。蜂群在越夏期间飞逃的主要原因是缺蜜及巢虫危害。当地中蜂在秋季大流蜜初期发生分蜂，分蜂群势均为８框足蜂以上，７框左右不分群。为控制不同起繁群势的蜂群在秋季大流蜜初期正好繁殖到７框左右，不致因分蜂影响秋冬蜜的采集，应分期起步秋繁。根据本试验所建秋季起繁群势（ｘ）与达７框群势所需繁殖天数（ｙ）之间的回归直线方程推算，在起繁群势为１～５框蜂量时，最适的秋繁开始期，１框群为７月３１日，２框群８月１０日……蜂群的基础群势每增加一框，则秋繁开始期应相应推迟１０～１１天。     

新太湖猪选育过程中近交技术的应用及效应分析

利用新太湖猪选育过程中（１９８６～１９９４）６个世代母猪的分娩产仔记录,后备猪生长发育测定资料,分析了近交对繁殖性能和生长发育性状的影响。相关分析表明,近交与产仔数、产活仔数的相关系数分别为－０．１６２５、－０．１５４６。与１８０日龄活重、体高、胸围、及８０ｋｇ时背膘厚度的相关系数分别为－０．１３５,－０．２１１,－０．２１８,－０．２０４。回归分析表明,近交系数每上升１０％,产仔数下降０．３９头,１８０日龄活重下降１．５ｋｇ,背膘厚下降０．０７４８ｃｍ。产仔记录分析表明,母猪近交系数在２０％以下时,产仔数比非近交组下降０．２７头,差异不显著（Ｐ＞０．０５）;近交系数在２０％以上时,下降１．３５头,差异不显著（Ｐ＞０．０５）。生长发育性状表明,近交系数在３０％以上时,１２０日龄活重、１８０日龄活重等性状都显著下降。８０ｋｇ活体背膘厚当个体近交系数上升到２０％以上时,与非近交组相比下降０．１６ｃｍ,差异显著（Ｐ＜０．０５）。     

Cloning and Sequence Analysis of Major Histocompatibility Complex Ⅰ Gene from Goose F1 of Fast-growth Lines

According to the multiple alignments identified major histocompatibility complex Ⅰ (MHC Ⅰ) gene conserved sequence registered in GenBank from the family ducks (Anatidae) anser waterfowl, a pairs of specific primers for the fragments of MHCⅠgene of goose F1 from fast-growth lines were designed and synthesized by Primer Premier 5.0. Using the genome DNA of goose F1 from fast-growth lines, the target gene fragment was obtained by PCR. To conduct sequencing of the fragments of MHCⅠgene of goose F1 from fast-growth lines and make sequence alignment and analysis of protein structure and function by bioinformatics, and research the characteristics of MHCⅠgene of goose F1 and the physicochemical properties of the protein. Bioinformatics was analyzed the nucleic acid data, deduced amino acid sequence and phylogenetic trees. The result of sequence analysis showed that the fragments of MHCⅠgene of goose F1 from fast-growth lines was 1036 bp in length, which coded 96 amino acids polyprotein. The homology were 93% and 83% with MHC Ⅰ gene and coding sequence of Wulong goose in NCBI respectively. There were 72 different bases sequence and 16 amino acids change. There also was higher homology with other poultry, and existed genetic relationship of Siji goose > chickens > ducks.The homology segment sequences corresponding to the fragments of MHCⅠ gene of goose F1 coded 96 amino acids protein, which molecular weight, PI, positively or negatively charged amino acid, estimated half-life, instability index, aliphatic index and average hydrophobicity were 11.342 ku, 5.32, 14, 17, 2.8 h, 34.92, 42.81, -1.066, respectively, and appeared 9 B cell epitopes, but contained no signal peptide. These results indicated that the protein for hydrophilic non-secreted proteins, had the high immunogenicity. In addition, The protein structure study indicated that alpha-helix, beta-sheet, beta-turn and random coil were 31.25%,16.67%, 14.58% and 37.50%, respectively. There existed amino terminal domain and carboxyl terminal domain in the tertiary structure. Therefore, MHC gene had significant difference between species and populations of individuals by the pathogen pressure in environment, and there were the interaction between polymorphism of MHC molecules and the diversity of antigenic peptide. MHC determined the differences of individual susceptibility to disease, and could be treated as a candidate gene for disease resistance.     

华亭县肉牛养殖业发展现状及对策建议

华亭县自古以来就是黄牛的主产区之一,又是秦川牛、早胜牛的边缘产区,养牛已成了当地农户发展致富的主导产业。本文在调查研究的基础上,对华亭县肉牛养殖业发展中存在的问题进行了综合分析,基础母牛保护力度不大、资金短缺、技术匮乏、基础设施落后,产业加工链短是制约华亭县肉牛养殖业发展壮大的主要瓶颈,针对以上问题,提出了一些可行的对策建议,以促进该县进一步加快肉牛改良、扩繁和规模化发展,降低养殖户养殖成本,提高经济效益。     

抗旱耐热白三叶新品种选育初报

鄂牧一号白三叶是以美国瑞加和路易斯安那两个白三叶品种为原始材料，经单株抗性造反份系比较鉴定，多系混合杂交，品种比较和区域试验选育而成，历时１０年。该品种具有高产，抗旱，耐热和粗蛋白含量高等特性，是南方低山丘陵地区有推广应用前景的优良牧草和草坪植物。