中国野牦牛遗传资源的保存与利用

野牦牛是青藏高原珍贵的野生畜种资源。本文从野牦牛的分布、类型、种群数量以及主要地理分区等方面分析了中国野牦牛遗传资源现状,同时讨论了野牦牛的生物学特性和经济价值,并提出了保存和利用野牦牛遗传资源的措施,对促进高寒牧区生态效益和社会效益有着重要的意义。     

猪泛素基因与PRRSV GP5基因融合表达质粒的构建及其免疫效果

构建了泛素（ubiquitin，Ub）基因与密码子优化的PRRSVGP5蛋白（optiGP5）基因融合表达质粒pIR—Ub—optiGP5。间接免疫荧光和Western—blot分析表明，重组质粒转染293T细胞后能够瞬时表达。将pIR—optiGP5和pIR—Ub—optiGP5两种质粒DNA肌肉注射免疫BALB／c小鼠后，分别检测小鼠血清中抗GP5抗体、T淋巴细胞的增殖能力以及CTL活性。结果显示，pIR—optiGP5质粒免疫组在二免后可以检测到荧光抗体，而pIR—Ub—optiGP5质粒免疫组一直未检测到抗GP5抗体，但该免疫组的T淋巴细胞增殖指数及针对GP5的特异性CTL反应数值明显高于pIR—optiGP5质粒免疫组。这表明泛素与GP5的融合表达可增强细胞免疫反应。     

不同刈割时间收获后的羊草、芦苇水分和呼吸的变化

以多年生草本植物羊草和芦苇为实验材料,研究1d中不同时间（9∶00、13∶00、17∶00）刈割后含水量、气孔导度及呼吸速率的变化。结果表明：（1）羊草、芦苇刈割后水分散失均经历三个阶段：快速失水1d,缓慢失水2～3d,平稳期1d。芦苇叶片呼吸速率下降快,刈割5h后呼吸微弱,接近死亡;羊草叶片呼吸速率下降慢于芦苇,刈割7h后仍存在生理活动;（2）依据水分散失和呼吸代谢指标,三个刈割时间中,9∶00刈割能最大程度地减少干草调制过程中的养分损失,有益于制作优质干草。     

超临界萃取技术及其在蜂产品加工中的应用

本文简要介绍了超临界萃取技术及其在蜂产品提取中的应用。     

青藏高原江河源区退化草地人工改良措施对高原鼠兔种群动态影响

通过对江河源区退化草地采取建植人工和半人工草地的措施进行改良,以影响害鼠(高原鼠兔)种群,达到防治鼠害的目的。     

尖扎县草地畜牧业生产现状及可持续发展对策

通过对尖扎县草地畜牧业生产现状及其发展的制约因素分析,提出了畜牧业可持续发展的对策。     

披碱草属植物遗传多样性研究进展

综述了近年来国内外关于披碱草属(Elymus L.)植物遗传多样性的研究现状和存在的问题,同时讨论了其作为重要种质资源的应用前景。     

渭北旱塬优质苹果种植的农业地质环境特征

渭北旱塬是我国苹果种植的最优气候区。以白水县为例，通过对其气候适生区内果园地质条件的对比分析，寻找出了具体地质要素间的差异，归结出了两类气候区内地貌、土壤母质类型、母质矿物质含量三类要素的组合类型，为进一步探讨地质条件对苹果品质的影响特征，细分气候优生区，促进该区苹果生产优质化提供依据。     

Isolation,Identification and Biological Characteristics of Staphylococcus chromogenes from Tibetan Pigs

In order to understand the infection of Staphylococcus disease in healthy Tibetan pigs in Linzhi city,Tibet.232 samples were collected from the slaughterhouse in Bahe town,Gongbujiangda county,Linzhi city,Tibet,the teaching practice ranch at the Tibet Agriculture and Animal Husbandry University in Bayi district,Linzhi city,and the slaughterhouse in Bayi district,Linzhi city.These samples were isolated,cultured and identified,and one isolated strain was systematically studied for biological characteristics.Epidemiological survey results showed that 73 of 232 samples were positive for Staphylococcus,the positive rate was 31.47%,16 positive samples were detected in the slaughterhouse of Bahe town,Gongbujiangda county,Linzhi,Tibet,with a detection rate of 23.89%(16/67),43 positive samples were detected in the pastures of the teaching practice ranch at the Tibet Agriculture and Animal Husbandry University in Bayi district,Linzhi city,with a detection rate of 34.40% (43/125),14 positive samples were detected in the slanghterhouse in Bayi district,Linzhi city,with a detection rate of 35.00% (14/40).Through PCR identification,gene sequencing and biochemical identification,5 strains of Staphylococcus chromogenes were isolated,and one of them (Sa LZ1) was studied systematically.The biological characteristics of the isolated strains showed that the Sa LZ1 strain formed round white convex colonies on the agar medium,with regular edges,smooth surfaces,and opaque white colonies.The isolates were Gram-positive cocci bacteria.PCR sequencing results showed that the isolate had the highest homology with Staphylococcus chromogenes (GenBank accession No.:MG576253.1),positive for serum inulin,manicol,glucose,saccharose,lactose,negative for arabinose,sodium hippurate,raffinose,xylose,urea,etc,consistent with the biochemical characteristics of Staphylococcus chromogenes.The logarithmic growth period of isolated bacteria was 5 to 10 h.The pathogenicity test of mice showed that the mortality rate of mice reached 100% when the concentration of Sa LZ1 strain reached 3.5×10⁹ CFU/mL.And the results of pathological section showed that Sa LZ1 strain could cause the visceral tissue of mice to develop pathological changes.The above results provided a theoretical basis for the prevention and control of Staphylococcus suis in Linzhi,Tibet.     

Effect of Supplementing Alfalfa Powder to Diet on Growth Performance and Meat Quality of Goose

The experiment was aimed to investigate the effects of dietary alfalfa powder on the growth performance,body size,slaughter performance,organ index and meat quality of Siji geese.A total of 256 15-day-old geese (half male and half female) with similar body weight were randomly divided into four groups with 4 replicates of 16 geese each.The geese in control group were fed with corn-soybean meal-based diet (control diet),and geese in the experimental groups were fed the basal diet replaced with 10%,20% and 30% alfalfa powder,respectively.The results showed that,compared with the control group,dietary alfalfa powder supplementation had no significant effect on the average daily intake,average daily gain,feed conversion ratio,body oblique length,keel length,shin circumference,semi diving length,chest width and shin length (P>0.05),and also had no effect on the carcass ratio,half-eviscerated carcass ratio and pectoral muscle ratio (P>0.05).However,dietary 20% and 30% alfalfa powder supplementation significantly increased the chest depth (P<0.05),dietary 30% alfalfa powder significantly decreased the full-eviscerated carcass ratio (P<0.05),and dietary 10% alfalfa powder significantly increased the leg muscle ratio (P<0.05) of geese.In addition,dietary alfalfa powder significantly decreased the abdominal fat ratio (P<0.05),raised the growth index of liver,jejunum,ileum,and cecum (P<0.05),and increased the water loss rate of pectoral muscle and leg muscle (P<0.05) compared with the control group.Dietary 10% and 30% alfalfa powder significantly increased duodenal growth index (P<0.05) of geese.In conclusion,dietary alfalfa powder supplementation might improve the slaughter performance (increase chest depth and leg muscle ratio,reduce abdominal fat rate) and organ growth index (increase the growth index of liver,duodenum,jejunum,ileum and cecum).However,dietary alfalfa powder increased water loss rates in pectoral muscle and leg muscle,and 30% alfalfa powder reduced the full-eviscerated carcass ratio of geese.The appropriate supplementation level of alfalfa powder was recommended at 10% in the present study.