鸡的输尿管引出手术

本试验使用５只成年母鸡,采用８４６合剂全身麻醉,伏卧或卧保定,进行输尿管引出手术,手术分两步进行,最后使输尿管开口从泄殖腔壁上游离出来,固定并暴露于尾下肛门上方的体表。试验结果表明,手术对我明显不良影响,术后鸡正常采食和产蛋,能长期饲养并分别采集单纯的尿液和粪便,可作为一种有用的试验动物模型。     

冷季型草坪草在过渡气候带的适应性研究

1995～1999年在过渡气候带进行了四种不同冷季型草坪草的引种试验.结果表明,高羊茅是实现草坪四季常绿的首选草种;草地早熟禾观赏性比高羊茅好,但有黄绿期;多年生黑麦草和匍匐翦股颖的观赏性最好,但在夏季要大片枯死,可用于临时性草坪建植,不适合作永久性草坪草.     

THE FIRST TWENTY-ONE YEARS OF VETERINARY DIAGNOSTIC ULTRASOUND

The veterinary literature of 1966–1986 was searched for articles and books related to the use of diagnostic ultrasound in animals. There were 492 references, categorized as follows: general, 30; small animal applications, 169; large animal applications, 248; blood pressure measurement, 23; ultrasound-guided biopsy, 4; miscellaneous, 18.     

鸡lncRNA-MSTRG.15568.9及其预测靶基因的表达

试验旨在了解在鸡睾丸中高表达的1个长链非编码RNA （long non-coding RNA,lncRNA）及其预测靶基因的时空表达规律,研究二者在鸡弱精子症中的调控作用。根据弱精子症和正常北京油鸡公鸡睾丸转录组测序筛选到的1个高表达的lncRNA （MSTRG.15568.9）,采用顺式（cis）作用模式预测其潜在靶基因SPAG4（sperm-associated antigen 4）,进一步采用实时荧光定量PCR方法进行表达量分析。分别选择3只0、5、20、30、45、60周龄正常北京油鸡公鸡,检测MSTRG.15568.9与SPAG4基因在不同周龄公鸡睾丸中的表达量差异;选择30周龄3只正常公鸡,采集睾丸、肝脏和脾脏等8个部位组织样品,检测MSTRG.15568.9与SPAG4基因在不同组织间的表达规律;选择45周龄弱精子症公鸡和正常公鸡各3只,对比MSTRG.15568.9与SPAG4基因在睾丸的表达量差异。结果显示,MSTRG.15568.9与SPAG4存在明显的时空表达差异,且二者表达趋势基本一致。在不同周龄的鸡睾丸组织中,MSTRG.15568.9和SPAG4的表达趋势相近,MSTRG.15568.9在20周龄的表达量显著高于0、5、30、45、60周龄（P<0.05）,0和5周龄表达量显著低于20、30、45和60周龄（P<0.05）;SPAG4在45周龄表达量最高,其次是20周龄（P<0.05）。MSTRG.15568.9和SPAG4在睾丸和肝脏中的表达量均显著高于脾脏、肾脏等组织（P<0.05）;在正常睾丸组织中的表达量均显著高于弱精子症睾丸组织（P<0.05）。综上所述,MSTRG.15568.9与SPAG4基因具有较明显的组织表达特异性,且MSTRG.15568.9可能调控SPAG4基因的表达,参与精子发生与精子活力调控;但其具体作用机制需要进一步探索。本研究可为鉴定与鸡弱精子症调节机制相关的功能基因提供参考。     

牛粪不同堆储处理方法微生物数量变化的研究

以牛粪为原料,研究露天堆储、粪池堆储和遮雨堆储三种处理在不同时间段微生物变化规律,为合理有效的处理畜禽粪污提供科学参考.结果各处理在堆储过程中的微生物总数呈山型的变化,其中细菌的数量变化类似于微生物总数的变化;真菌的数量变化呈现一条类似于"W"型曲线;放线菌一直呈下降趋势;微生物总量在15、30、45、60、75 d,处理3与处理1和处理2 差异显著(P<0.05),第30 d处理2与处理1差异显著(P<0.05).     

黄河源区“黑土滩”混播草地牧草植物量及营养动态初探

黄河源区的极度退化草地——"黑土滩",改建成人工草地是一种恢复退化草地的重要途径,同时可以收获大量饲草。对"黑土滩"混播草地(垂穗披碱草Elymus nutans+中华羊茅Festuca sinensis+碱茅Puc-cinellia distans+冷地早熟禾Poa crymophila+赖草Leymus secalinus)的生产力和营养价值动态进行了研究,分析了放牧对草地生产力的影响。结果表明,从生长高峰期8月到翌年4月,草地生产力自然损失量为144.3 g/m2,损失率为34.9%。这期间放牧利用导致牧草被采食187.2 g/m2。传统的放牧利用,使该类人工草地利用率为45.2%。冷季草地牧草营养价值全都下降,粗蛋白含量降低了69.86%,粗脂肪降低了65.85%。该"黑土滩"混播草地在夏季属碳氮营养型(CN),冬季属碳营养型(C)。因此建议,"黑土滩"混播草地在夏季生长高峰期适度进行人工割草,冬季进行适度放牧利用。     

36个燕麦品种不同部位养分分布格局

分析了天祝高寒草甸区36种不同饲用燕麦(Avena sativa)叶片、籽粒和茎秆中的水分、灰分、粗蛋白、可溶性糖、粗脂肪、磷、钙、粗纤维、中性纤维和酸性纤维含量的分布特征。结果显示:36个燕麦品种叶片中水分、灰分、粗蛋白、可溶性糖和钙含量显著高于籽粒和茎秆(P0.05),平均值分别为6.36%、9.28%、19.82%、13.71%和0.25%;籽粒中粗脂肪和磷含量显著高于叶片和茎秆(P0.05),平均值分别为:4.48%和0.25%;茎秆中粗纤维、中性洗涤纤维和酸性洗涤纤维含量显著高于叶片和种子(P0.05),平均值分别为35.62%、65.18%和56.40%。总之,36种燕麦不同部位的营养价值高低依次为叶片籽粒茎秆。     

过氧化物酶和苯丙氨酸解氨酶与苜蓿白粉病抗性的关系

以8个对白粉病有不同抗性的苜蓿品种(Medicgo sativa L.)为材料,研究人工接菌后叶片过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性的变化及其与抗病性的关系。结果表明:未接菌的品种间PAL活性差异不显著,而POD活性则差异显著(P<0.05);感病品种POD活显著高于抗病品种;接种白粉病菌后,供试品种间叶片PAL活性和POD活性均升高,其中抗病品种间PAL活性升高幅度显著大于感病品种,其变化与病情指数呈负相关,而POD活性的变化则相反;POD活性和PAL活性与苜蓿品种对白粉病的抗性密切相关。     

Construction and application of a bovine immune-endocrine cDNA microarray

A variety of commercial DNA arrays specific for humans and rodents are widely available; however, microarrays containing well-characterized genes to study pathway-specific gene expression are not as accessible for domestic animals, such as cattle, sheep and pigs. Therefore, a small-scale application-targeted bovine immune-endocrine cDNA array was developed to evaluate genetic pathways involved in the immune-endocrine axis of cattle during periods of altered homeostasis provoked by physiological or environmental stressors, such as infection, vaccination or disease. For this purpose, 167 cDNA sequences corresponding to immune, endocrine and inflammatory response genes were collected and categorized. Positive controls included 5 housekeeping genes (glyceraldehydes-3-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, ribosomal protein L19, beta-actin, beta2-microglobulin) and bovine genomic DNA. Negative controls were a bacterial gene (Rhodococcus equi 17-kDa virulence-associated protein) and a partial sequence of the plasmid pACYC177. In addition, RNA extracted from un-stimulated, as well as superantigen (Staphylococcus aureus enterotoxin-A, S. aureus Cowan Pansorbin Cells) and mitogen-stimulated (LPS, ConA) bovine blood leukocytes was mixed, reverse transcribed and PCR amplified using gene-specific primers. The endocrine-associated genes were amplified from cDNA derived from un-stimulated bovine hypothalamus, pituitary, adrenal and thyroid gland tissues. The array was constructed in 4 repeating grids of 180 duplicated spots by coupling the PCR amplified 213-630 bp gene fragments onto poly-l-lysine coated glass slides. The bovine immune-endocrine arrays were standardized and preliminary gene expression profiles generated using Cy3 and Cy5 labelled cDNA from un-stimulated and ConA (5 microg/ml) stimulated PBMC of 4 healthy Holstein cows (2-4 replicate arrays/cow) in a time course study. Mononuclear cell-derived cytokine and chemokine (IL-2, IL-1alpha, TNFalpha, IFN-gamma, TGFbeta-1, MCP-1, MCP-2 and MIP-3alpha) mRNA exhibited a repeatable and consistently low expression in un-stimulated cells and at least a two-fold increased expression following 6 and 24 h ConA stimulation as compared to 0 h un-stimulated controls. In contrast, expression of antigen presenting molecules, MHC-DR, MHC-DQ and MHC-DY, were consistently at least two-fold lower following 6 and 24 h ConA stimulation. The only endocrine gene with differential expression following ConA stimulation was prolactin. Additionally, due to the high level of genetic homology between ovine, swine and bovine genes, RNA similarly acquired from sheep and pigs was evaluated and similar gene expression patterns were noted. These data demonstrate that this application-targeted array containing a set of well characterized genes can be used to determine the relative gene expression corresponding to immune-endocrine responses of cattle and related species, sheep and pigs.     

平衡是硬道理——维生素应用误区浅析

饲料中能量、氨基酸、脂肪酸、微量元素和维生素等营养成分在消化、吸收、代谢上存在各种互作关系,所以饲料配方不仅要满足动物对各种营养成分的单一需要,而且要通过平衡各营养成分之间的比例,达到营养全价、平衡。例如,日粮中能量水平和粗蛋白含量之间存在一个最佳的比例范围,高能量低蛋白和低能量高蛋白饲料都必然降低饲料转化效率,影响家禽生产性能的发挥。本文试图在动物营养中引入维生素平衡的概念,介绍维生素平衡的表现形式和破坏维生素平衡的因素,分析在动物生产中维生素应用的常见误区并提出相应的解决办法。