我国牧草引种及其适应性鉴定概况

对我国牧草引种的目的、原则和现状进行了概述,并对引种牧草适应性鉴定的内容加以概括.     

引种牧草造成生物入侵的现状及原因分析

分析了引种牧草造成杂草入侵的原因:难以科学地评价牧草的潜在入侵风险性,造成盲目引种;牧草具有入侵杂草的生物学特征;引种气候相似性原则利于牧草成为入侵杂草;缺乏天敌控制利于牧草成为入侵杂草;种植制度利于牧草成为入侵杂草.     

牧草和饲料作物的引种选育及其发展趋势浅淡

简单介绍了引种选育牧草和饲料作物的种类,就目前牧草和饲料作物的引种选育的发展趋势做出了进一步阐述,并提出了现阶段牧草和饲料作物的引种选育必须切实关注的几个问题,以期给牧草和饲料作物的引种选育工作人员提供理论的支持和帮助。     

因地制宜选种牧草

近年来 ,随着农业、畜牧业生产结构调整的加快和国家退耕还林还草战略的全面实施 ,牧草的栽培种植面积越来越大。牧草引种栽培的迅速发展 ,使原有的牧草品种的地区局限性逐渐缩小 ,取而代之的是跨越地域甚至是国界的牧草种子、种苗、种根的输出和引种。但在牧草的引种及栽培中 ,很多地方由于缺乏对牧草引种的自然及生态规律的认识 ,从而导致了盲目引种与栽培 ,如在有的地方因引种了不适宜当地生长的苜蓿品种而出现了种植的苜蓿大面积死亡的现象。更有甚者出现了生态性灾害的悲剧 ,如在江南一些地区引进的水葫芦既污染了水体又对航运产生了不…     

澳大利亚牧草在江西红壤丘陵岗地引种试验初报

近年来随着我国南方畜牧业及渔业的发展，对牧草的需求量日益增加。人们很希望能获得高产优质的牧草，以提高牧草的生产能力和质量，就需要通过引种或育种来解决这个问题。对于后者来说，要育出一个新的品种，需要较长的时间，而通过引种就可以将其他地方的一些优质牧草种或品种直接引进种植，一旦引种成功就可直接推广而产生经济效益。因此，引种是解决优质牧草缺乏的很好方法。     

澳大利亚牧草在江西红壤丘陵岗地引种试验初报

近年来随着我国南方畜牧业及渔业的发展,对牧草的需求量日益增加.人们很希望能获得高产优质的牧草,以提高牧草的生产能力和质量,就需要通过引种或育种来解决这个问题.对于后者来说,要育出一个新的品种,需要较长的时间,而通过引种就可以将其他地方的一些优质牧草种或品种直接引进种植,一旦引种成功就可直接推广而产生经济效益.因此,引种是解决优质牧草缺乏的很好方法.     

黔西北高原引种优良牧草持久性研究

对１９８５年引种栽培的１４种禾本科和豆科牧草的观测研究表明，在放牧管理及当地生态条件下，引种牧草历经９年以后，干物质产量仍然保持较高水平的牧草种为鸭茅和紫羊茅，其次为多年生黑麦草、高牛尾草、早熟禾和白三叶。引种牧草竞争力最强的牧草种为鸭茅和紫羊茅，高牛尾草、多年生黑麦草和白三叶。而侵入性最强的牧草种为白三叶和黑麦草，两者的产量之和占侵入草总量的９９％。     

不要盲目引种牧草

目前,几乎所有科技类、信息类报刊上都有出售牧草种子的广告,多为牧草高营养高利润的宣传,却没有各种牧草特性的介绍,使很多农牧民不能全面了解牧草的品质和用途,因而引种时带有一定的盲目性。为避免引种风险,引种牧(饲)草前一定要对各种牧草品种适宜种植地和宜饲养哪种畜禽作一些了解,这样才能提高种养经营效益。 1.一般单子叶牧草如黑麦草、黑西哥玉米、苏     

牧草种植技术问答

1．牧草引种时应该注意哪些事项？答：（1）牧草的适应性：根据当地具体情况,选择适应当地生态环境的牧草;（2）牧草的丰产性：引种以割草利用为目的,应选用生物产量高的牧草,在生育期方面应以1、2年生牧草为主。     

优质牧草菊苣的引种试验

根据四川省凉山彝族自治州昭觉县竹核乡和尔古乡的自然资源条件进行了优质牧草菊苣的引种及栽培试验,并对优质牧草菊苣的特征特性、引种栽培技术、应用价值及范围作了介绍。     

6种鹅观草属植物叶片形态解剖特征比较

为比较鹅观草属(Roegneria C.Koch.)不同种植物间的叶片形态解剖特征,将不同来源的6种鹅观草属植物在内蒙古太仆寺旗典型草原(中国农业科学院太仆寺旗草地资源生态监测与评价野外科学观测试验站)种植,运用刮片法和石蜡切片法将其成熟叶片制成切片,光学显微镜下观察叶片下表皮的4项表型性状,并测定叶片下表皮和叶横切面的17项数量性状指标。结果表明:6种鹅观草属植物叶片表型特征较一致,测量指标中气孔长宽比和长细胞长度变异系数较大。方差分析表明,叶中脉厚、叶厚、上表皮厚、气孔指数等12项指标在6种植物间差异均达到显著或极显著水平,因此这些指标能作为鹅观草属内种间的分类依据。主成分分析表明,17项数量指标的主要信息集中在前3个主成分上,分别是叶片储水和输水功能结构、叶片表皮特征结构以及抵抗逆境的结构。聚类分析将这6种植物聚成3类,即黑药鹅观草(R.melanthera Keng)和垂穗鹅观草(R.nutans Keng)各为一类,纤毛鹅观草(R.ciliaris Nevski)、多变鹅观草(R.varia Keng)、直穗鹅观草(R.turczaninovii Nevski)和肃草(R.stricta Keng)聚为另一类,这与该属植物形态学上的分类相同。因此,叶片解剖结构特征可以作为分类学上的重要依据。     

Prevalence of diseases of the spinal cord of cats

A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.     

野生黄鼬消化管组织结构的观察

通过组织学观察,探讨野生黄鼬消化管的组织结构特点.将8只野生黄鼬经乙醚麻醉后处死,解剖取食管、胃、小肠、大肠,制作石蜡切片,观察其组织结构.结果显示野生黄鼬食管的黏膜为复层扁平上皮,食管腺发达,肌层以骨骼肌为主.胃贲门部有发达的皱襞和贲门腺;胃底腺有大量的主细胞和壁细胞;胃大弯部的腺体以壁细胞为主,仅有少量主细胞;胃幽门部有发达的幽门腺和大量壁细胞.十二指肠黏膜层有小肠腺,内有潘氏细胞存在,黏膜下层含有十二指肠腺;空肠可见孤立淋巴小结、弥散淋巴组织及集合淋巴小结.结肠无皱襞和肠绒毛,大肠腺排列紧密,其中杯状细胞特别多;直肠固有膜内有发达的大肠腺.所以野生黄鼬消化管的特点是胃各部胃腺发达,壁细胞特别多.     

苜蓿侧根发生与内源激素的变化

研究根系发育能力不同的苜蓿品种在主根受伤后内源激素的变化。结果表明,主根伤害后,根组织生长素含量上升,根系发育能力越强者,增加量越大。细胞分裂素(玉米素、异戊烯基腺嘌呤、双亲玉米素)和赤霉素在处理后1周时下降,随后逐渐回升。生长素/细胞分裂素、生长素/赤霉素和生长素/脱落酸的比值在处理后1周时明显增加,随后逐渐下降。叶片和根组织激素分布不一致,其中叶片生长素含量相对较高,根组织细胞分裂素含量相对较高。伤害主根后1周时,叶片细胞分裂素和生长素含量明显下降,随后逐渐回升,根系发育能力越强者恢复正常含量越快。     

崇明陈家镇示范绿地两栖类调查

2007年4月至2008年7月,对崇明陈家镇示范绿地两栖类进行调查,根据两栖类资源和生境的特点,选取了17处调查地点。共记录到泽蛙、中华蟾蜍、黑斑蛙、金线蛙等两栖类4种,共计546只,其中泽蛙329只,占总数的61%,优势明显。在不同栖息生境中浅滩观测到两栖类种类最多,4种两栖类都观测到,在林带观测到的两栖类有266只,占总数的49%,数量最多,不同生境两栖类分布差异显著。不同水域中沟浜分布的两栖类有4种,达到全部观测4种记录,同时沟浜观测到两栖类303只,占总数的55%,数量最多,两栖类分布受水域性质影响显著。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

外源激素催乳对小牛泌乳的影响

利用外源激素刺激小牛泌乳的研究鲜有报道.研究对8月龄小牛进行外源激素注射,诱导小牛泌乳,并对催乳乳汁的乳脂、总蛋白、乳糖、干物质含量进行了分析.结果表明外源激素能有效刺激小牛泌乳,乳汁成分没有发生明显变化.这对快速鉴定转基因牛是否能生产活性蛋白具有一定意义.     

两种绿头鸭肌肉营养成分分析及评价

本试验旨在研究两种绿头鸭（白羽绿头鸭和绿头鸭）肌肉营养组成和价值,为绿头鸭肉产品的开发利用提供基础数据和理论依据。选择白羽绿头鸭和绿头鸭60只（每个品种各30只,公母各半）,依照国家标准测定胸肌粗蛋白质、粗脂肪、胆固醇含量及氨基酸、脂肪酸、微量元素和维生素的组成和含量,并对胸肌进行氨基酸评价及脂肪酸营养价值评价。结果显示,白羽绿头鸭肌肉粗蛋白质含量显著低于绿头鸭（P<0.05）;两种绿头鸭肌肉中均检测到17种含量大于0.01%的氨基酸,其中白羽绿头鸭肌肉苏氨酸、组氨酸、丝氨酸和脯氨酸含量显著高于绿头鸭（P<0.05）,赖氨酸、谷氨酸和精氨酸含量显著低于绿头鸭（P<0.05）;检测到13种含量均大于0.01%的脂肪酸,其中白羽绿头鸭硬脂酸和油酸含量显著低于绿头鸭（P<0.05）;检测到9种矿物质元素（钠、镁、钾、钙、锰、铁、铜、锌和硒）,两种绿头鸭差异不显著（P>0.05）;检测到8种维生素,白羽绿头鸭肌肉维生素B₁含量显著高于绿头鸭（P<0.05）,维生素D和维生素E含量显著低于绿头鸭（P<0.05）。两种绿头鸭肌肉氨基酸比例接近世卫组织推荐的理想模式,富含人体所需的矿物质元素和维生素,具有广阔的开发利用前景。     

Characterisation of isolates of Haemophilus paragallinarum from Indonesia

OBJECTIVE: To characterise 18 isolates of Haemophilus paragallinarum isolated from chickens in Indonesia. PROCEDURE: The isolates were identified to species level by traditional phenotypic methods. Six of the isolates were also identified by a species-specific polymerase chain reaction. Fourteen of the isolates were examined for resistance to a panel of seven antimicrobial agents using a disc diffusion method. All 18 isolates were serotyped according to the Page scheme using reference antisera in a haemagglutination inhibition test. RESULTS: Four of the 18 isolates were obtained from indigenous (kampung) chickens, with the remainder being from typical intensive poultry production systems. The 18 isolates were obtained from 11 outbreaks that showed the typical clinical signs of infectious coryza and 11 of the isolates were obtained from chickens that had been vaccinated with infectious coryza vaccines. All 18 isolates were confirmed as H paragallinarum by biochemical testing and six isolates were also identified as H paragallinarum by the polymerase chain reaction test. Eleven isolates were resistant to erythromycin and streptomycin, 10 to neomycin, eight to oxytetracycline, five isolates to doxycycline, three to sulphamethoxazoltrimethoprim but only one to ampicillin. Seven isolates were Page serovar A, four were Page serovar B and seven were Page serovar C. CONCLUSION: The presence of all three Page serovars (A, B and C) has been confirmed for the first time in Indonesian chickens. As the majority of the infectious coryza vaccines in use in Indonesia contain only serovar A and C, the presence of serovar B in chickens indicates that the protection by these bivalent vaccines would be reduced. The use of trivalent infectious coryza vaccines that contain serovars A, B and C is recommended for use in Indonesia.     

Analysis and Evaluation of Nutrient Composition of Muscles of Two Kinds of Mallard

This experiment was aimed to study the nutritional content and value of the muscles of two mallards (White feather mallard and mallard),and provide basic data and theoretical basis for the development and utilization of mallard meat products.60 White feathered mallards and mallards (30 for each breed,half of male and female) were chosen,and the composition and content of pectoral muscle crude protein,crude fat,cholesterol,amino acids,fatty acids,trace elements and vitamins were determined according to national standards and the nutritional values of muscle were evaluated.The results showed that the content of crude protein in muscle of White feather mallard was significantly lower than that of mallard (P<0.05).17 kinds of amino acids with contents higher than 0.01% were detected in the muscles of the two kinds of mallards,among which the contents of threonine,histidine,serine and proline in the muscles of the White feather mallard were significantly higher than those of mallard (P<0.05).The contents of lysine,glutamate and arginine were significantly lower than those of mallard (P<0.05).13 kinds of fatty acids with contents higher than 0.01% were detected,and the contents of stearic acid and oleic acid were significantly lower than those of the mallard.9 mineral elements (sodium,magnesium,potassium,calcium,manganese,iron,copper,zinc and selenium) in two kinds of mallards were detected,and there was no significant difference between the two kinds of mallards (P>0.05).8 kinds of vitamins were detected,and the content of vitamin B₁ in muscle of White feather mallard was significantly higher than that of mallard (P<0.05),but the contents of vitamin D and vitamin E were significantly lower than that of mallard (P<0.05).The ratio of amino acids in muscle of two kinds of mallards was close to the ideal model recommended by WHO,which was rich in mineral elements and vitamins for human body,and had a broad prospect of development and utilization.