不同环境条件下几种高寒草甸植物的非克隆繁殖投入和生长

通过对高寒草甸生态系统金露梅灌丛、矮嵩草草甸、围栏矮嵩草草甸以及模拟地球增温效应下5种植物繁殖投入和生长特性的测定,结果表明,矮嵩草、麻花艽、苔草以及美丽风毛菊的叶长沿对照矮嵩草草甸、0TC、围栏以及金露梅灌丛呈现上升趋势,只是灌丛中苔草和麻花艽两种植物的叶长较围栏和OTC有所下降,而环境变化对植物的叶宽的影响较小。苔草在金露梅灌丛中的繁殖投入最大,其次是矮嵩草草甸和围栏,OTC中苔草的繁殖投入几乎为零。围栏与矮嵩草草甸内苔草的繁殖投入差异不显著,而两者中植物的繁殖投入与金露梅灌丛相比,差异性显著(P<0.05)。矮火绒草在矮嵩草草甸中的繁殖投入最大,其次是0Tc和围栏,灌丛中矮火绒草的繁殖投入最小。OTC与矮嵩草草甸内矮火绒草的繁殖投入差异不显著,而OTC与围栏中矮火绒草的繁殖投入差异性显著(P<0.05)。由此我们可以得出一个结论:繁殖投入随环境梯度的变化,反映了植物繁殖对策和繁殖投入在整个生活史特征中的可塑性。     

不同环境条件下几种高寒草甸植物的非克隆繁殖投入和生长

通过对高寒草甸生态系统金露梅灌丛、矮嵩草草甸、围栏矮嵩草草甸以及模拟地球增温效应下5种植物繁殖投入和生长特性的测定,结果表明,矮嵩草、麻花艽、苔草以及美丽风毛菊的叶长沿对照矮嵩草草甸、OTC、围栏以及金露梅灌丛呈现上升趋势,只是灌丛中苔草和麻花艽两种植物的叶长较围栏和OTC有所下降,而环境变化对植物的叶宽的影响较小.苔草在金露梅灌丛中的繁殖投入最大,其次是矮嵩草草甸和围栏,OTC中苔草的繁殖投入几乎为零.围栏与矮嵩草草甸内苔草的繁殖投入差异不显著,而两者中植物的繁殖投入与金露梅灌丛相比,差异性显著(P＜0.05).矮火绒草在矮嵩草草甸中的繁殖投入最大,其次是OTC和围栏,灌丛中矮火绒草的繁殖投入最小.OTC与矮嵩草草甸内矮火绒草的繁殖投入差异不显著,而OTC与围栏中矮火绒草的繁殖投入差异性显著(P＜0.05).由此我们可以得出一个结论繁殖投入随环境梯度的变化,反映了植物繁殖对策和繁殖投入在整个生活史特征中的可塑性.     

藏北高寒草原典型物种凋落物分解与养分动态

凋落物分解在陆地生态系统碳循环和养分循环中起着重要作用,以往的研究主要集中在森林生态系统和温带草原生态系统,而对于高寒草原生态系统关注不足。本研究采用凋落物袋法,通过为期3年的野外分解试验,研究青藏高原北部高寒半干旱草原4种典型物种凋落物[紫花针茅(Stipa purpurea)、青藏苔草(Carex moocroftii)、火绒草(Leontopodium pusillum)、昆仑蒿(Artemisia nanschanica)]的分解动态。结果表明,4种凋落物的质量损失在不同物种和分解时间下存在显著差异,在试验结束时,各物种凋落物失重率大小顺序为昆仑蒿(46.69%)紫花针茅(44.97%)青藏苔草(33.55%)火绒草(17.05%);凋落物的分解常数在0.07～0.22,分解的半衰期在3.14～10.50年,分解的周转期在13.59～45.37年;分解过程中氮(N)、磷(P)养分主要表现为累积–释放和直接释放两种模式,在试验结束时,4种凋落物N、P养分的残留量均表现为火绒草青藏苔草紫花针茅昆仑蒿。本研究将丰富对高寒地区半干旱草原生态系统的生物地球化学循环过程的认识。     

青藏高原东缘短柄草-密生苔草草地植物群落组成及生产力的季节动态研究

通过对青藏高原东缘短柄草Brachypodium sylvaticum-密生苔草Carex crebra草地2年的定位监测研究,结果表明:该草地共有植物 70 种,分属 20 科 46 属.短柄草是优势种,占草群密度的45.5%;密生苔草为亚优势种.从地上植物量来看,短柄草产量在各月均居首位,所占比率为14%～29%,密生苔草占5.4%～16%.草地生产力月动态变化曲线呈单峰形,6-7月是地上植物量增长最快的时期,产量高峰出现在8月(217.9 g/m2).全年单位面积载畜量为2.388个羊单位/(hm2*年),青草期5-10月各月理论载畜量分别为:4.6,9.3,17.4,28.1,21.2,11.6个羊单位/hm2.     

石羊河上游两种退化草地植物群落特征分析

采取分层取样法,对石羊河上游阿尔泰狗哇花+阿尔泰针茅型和火绒草+阿尔泰针茅型两种退化草地群落特征进行了分析。结果表明,(1)两种毒杂草型草地物种丰富度之间没有显著差异,但群落数量结构及群落成员型明显不同:阿尔泰狗哇花+阿尔泰针茅型草地中,阿尔泰狗哇花占优势地位,阿尔泰针茅次之;多年生杂类草盖度和植物量高于禾本科牧草;地下植物量自表层向下依次减小,且主要集中在0~20 cm土层。火绒草+阿尔泰针茅型草地,火绒草占优势地位,阿尔泰针茅次之;地下植物量变化趋势同阿尔泰狗哇花+阿尔泰针茅型草地。(2)两种退化草地群落功能型发生明显变化,表现为禾草∶杂类草比例与原生植被相比明显倒置。(3)两种退化草地总盖度略高于原生植物群落,差异不显著,但地上植物量明显高于原生植物群落。     

应用Logistic方程研究优良冷季型观赏草抗热性

高温是热带和亚热带地区冷季型观赏草生长发育的最大限制因子。本研究以叶片为材料,用改良电导法测定配合Logistic方程求拐点温度的方法测定了6种冷季型观赏草的高温半致死温度(LT50)。结果表明,经等梯度的高温处理后,待试材料叶片细胞伤害率和温度之间呈现明显的"S"形曲线,符合Logistic方程,拟合度较好。抗热性排序为:宽叶苔草(Carexsiderosticta)(LT50=53.5℃)皱苞苔草(C.chungii)(LT50=52.5℃)发状苔草(C.comans)(LT50=51.5℃)棕榈叶苔草(C.muskingumensis)(LT50=48.4℃)蓝灰石竹(Dianthus gratianopolitanus)(LT50=46.3℃)花叶虉草(Phalaris arundinacea)(LT50=44.8℃)。通过对供试材料在南京地区越夏情况的田间观测,发现宽叶苔草、皱苞苔草、发状苔草的长势良好,外观无任何变化,因此认为这3种观赏草的抗热性较强。     

青藏高原腹地退化青藏苔草草原植物生态位的特征

采用野外调查方法研究了青藏高原腹地退化青藏苔草草原植物生态位的特征,结果表明:随着青藏苔草草原的退化,青藏苔草的重要值和生态位宽度逐渐降低,莎草科的高山嵩草、禾本科的紫羊茅和波伐早熟禾、豆科的黄花棘豆和多枝黄耆的生态位宽度先升高后降低,轻度和中度退化阶段时最大,杂类草西伯利亚蓼自出现后随退化程度增强,其重要值和生态位宽度逐渐增加.不同退化阶段,植物间生态位重叠度最大的物种对存在分异,在未退化、轻度、中度和重度退化阶段,青藏苔草分别与矮火绒草、紫羊茅、珠芽蓼和高山嵩草的生态位重叠度最高;中度退化时,物种间生态位重叠度最低的是兰石草和线叶龙胆,但其余各阶段多枝黄耆是生态位重叠度最低的物种之一.     

铁卜加地区主要植物种群密度及其与气象条件关系的研究

利用铁卜加地区自1987年以来的主要植物种群密度和有关的气象因素资料，研究了植物密度变化及其与气象因素之间的关系。结果表明：五种主要牧草种群密度的排序是猪毛蒿（300株／m2）＞干生苔草（200～300株／m2）＞天山赖草（100～200株／m2）＞冷地早熟禾（50～100株／m2）＞紫花针茅（10～20株／m2）；其中天山赖草种群密度变异系数最小（50％左右），紫花针茅变异系数最大（75％～200％）。该地区降水与温度年际变化基本趋向一致。分析得出天山赖草、冷地早熟禾、干生苔草具有较强的气候适应性，紫花针茅、猪毛蒿、具有较差的气候适应性。     

北京野生苔草属植物资源调查及观赏性状评价

在北京地区的7个调查点发现了18种野生苔草属植物资源,对18种野生苔草属植物坪用观赏性状进行了观测。结果表明,青绿苔草（Carex breviculmis）、涝峪苔草（C.giraldiana）、白颖苔草(C.rigescens)、矮丛苔草(C.humilis)、早春苔草(C.subpediformis)、披针苔草（C.lanceolata）适合作草坪地被类植物,尖嘴苔草(C.1eiorhyncha)、疏穗苔草（C.remotiuscula）、长嘴苔草（C.longerostrata）和翼果苔草（C.neurocarpa）等适合作观赏草与其他植物配置应用。     

河北省昌黎县黄金海岸几种单子叶植物叶耐盐碱结构的研究

对生长在黄金海岸自然保护区盐碱生境的6种单子叶植物:芦苇Phragmites australis、矮生苔草Carex pumila、野牛草Buchloe dactyloides、看麦娘Alopecurus aequdis、牛筋草Eleusine indica、菵草Beck-mannia syzigachne的叶片进行了解剖研究,对这6种植物叶的上、下表皮角质层厚度、主脉厚、叶肉细胞密度、泡状细胞、维管束上、下两端厚壁细胞层数7个抗性指标进行了观测,并进行了方差分析和品种间的多重比较,得出6种植物耐盐、碱性大小依次为:矮生苔草>芦苇>牛筋草>野牛草>菵草>看麦娘。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。