中国草地外来入侵植物现状研究

草地是中国陆地生态系统的重要组成部分,外来入侵植物已对我国草地造成了严重的生态危害和经济损失。了解草地外来植物的种类组成和入侵现状,是加强草地入侵植物管控,开展有效防控措施的基础。本文基于文献报道和数据库资料,系统分析了我国草地外来入侵植物的种类组成、起源、生活型、入侵途径和分布区域。结果表明,我国草地生境现有外来入侵植物183种,隶属41科123属。其中,菊科植物最多,有47种;禾本科和豆科分别有30种、21种。入侵植物来源于美洲的物种最多,共占总数的56.2%;其次是欧洲和亚洲,分别占比23.14%,13.22%。生活型以一年生和多年生草本植物为主;有意引进是最主要的引入途径。我国草地外来入侵植物种类繁多且分布范围广,急需对其开展进一步的调查,全面监测追踪入侵种群动态,积极控制已产生严重危害的植物种类,实行预防在先、防治结合的原则。本文旨在为我国草地外来入侵植物防控工作提供可靠的理论参考。     

西藏昌都地区天然草地有毒植物调查

昌都天然草地作为西藏草地的重要部分,其草地类型、有毒植物种类及分布状况等基础数据缺乏。本研究通过实际调查,结果显示,昌都地区有毒植物约150种,其中草地有毒植物104种,隶属24科54属。有毒植物成为严重危害该地区草地畜牧业发展和生态安全的问题之一。本次调查为该地区草地有毒植物防控及开发利用奠定了基础。     

围栏封育对昭苏马场春秋草场植被恢复的影响

对昭苏马场未封育与封育春秋草场植被进行了调查分析,结果表明:未封育草地植物优势种是亚洲百里香和草原苔草,封育草地植物优势种是针茅和草原苔草;未封育草地植物种类为28种,群落盖度为62.8%,地下植物量1 452.7 g/m2;封育后草地植物种类为31种,群落盖度和地下植物量分别增加了41.0%和34.5%;禾本科草类的重要值由未封育的17.6%增加到封育后的35.2%,豆科和菊科草类基本保持稳定,封育后藜科和杂类草的重要值比未封育时减小了13.5%;封育草地的丰富度指数和多样性指数均大于未封育草地,而均匀度指数则相反。     

辉河国家自然保护区草地植物区系及多样性空间分布研究

保护区的建立对于保护物种多样性,保护生态环境尤为重要.对保护区草地植物区系、物种多样性的空间分布现状及规律的研究有助于保护区的管理.于2009年7-8月,对辉河国家自然保护区草地植物区系及植物多样性空间分布现状进行了研究,以期为辉河国家自然保护区的管理实践提供理论依据.结果表明:研究区有种子植物154种,分属30科,108属;研究地区草地植物区系地理成分较为简单,以世界广布类型占主导地位,草地植物以旱生草本为主;研究区域草地植物种类存在空间异质性,从高纬度到低纬度,草地植物种类呈现先增加后减少的趋势;在经度方向,自西向东植物种类同样呈现先增加后减少的趋势,且这种变化趋势与海拔高度变化有关.     

封育对云南退化山地草甸植物种类及盖度的影响

对云南退化的山地草甸进行了为期3年的禁牧封育,并对其进行监测,研究了禁牧封育对退化山地草甸的改良作用。结果表明,禁牧封育对恢复退化山地草甸物种丰富度和草地盖度有明显的效果。禁牧封育后草地植物的盖度明显提高,植物种类增加很快,植物组成发生了显著变化。经过3年的封育,植物种类由27种增加到57种,是封育前的2倍多,封育第4年,植物物种基本稳定。封育措施有效恢复了不同退化程度山地草甸的物种丰富度和草地盖度,遏制了草地退化,是治理南方草地退化的有效途径。     

蒙辽农牧交错区草地资源植物组成及分布概况

为了解蒙(内蒙古)辽(辽宁)农牧交错区草地资源植物概况,以内蒙古自治区与辽宁省交界处17个半农半牧县的草地为研究区域,采用野外样点调查与统计分析相结合的方法,确定研究区域主要草地资源植物类型,并分析蒙辽农牧交错区草地生态系统资源植物的种群分布特征和开发利用现状。结果表明:蒙辽农牧交错区有118种草地资源植物,隶属32科88属,药用资源植物85种,占总资源植物的72.03%;食用资源植物22种,占18.64%;工业用资源植物20种,占16.95%;防护和改造环境的资源植物14种,占11.86%。说明蒙辽农牧交错区药用资源植物和食用资源植物丰富,其中科尔沁左翼后旗、库伦旗和阜新市草地资源植物类型齐全,种类最为丰富。     

四川省甘孜州天然草地有毒有害植物种类及分布调查

1997～1999年对甘孜州天然草地有毒有害植物种类及分布进行了调查,主要有毒有害植物共计33科、81属、239种。通过调查,掌握了有毒有害植物的种类、分布、以及发生规律,可为有毒有害植物防除提供依据。     

中国天然草地有毒植物及其放牧家畜中毒病研究进展

中国是世界草地资源大国,天然草地作为我国面积最大的陆地生态系统和重要的绿色生态屏障,具有多种生态功能,同时也是发展草地畜牧业的重要基地和牧民最基本的生产生活资料。但长期以来,人们只重视天然草地的生产功能,而忽视了对天然草地生态系统的保护,使得我国天然草地长期处于过度利用状态,造成草地退化,进一步引发有毒植物等生物灾害多发、频发,可食牧草种类和产量锐减,生物多样性失调及生态环境恶化。本文简要概述了我国天然草地有毒植物的种类与分布,介绍了有毒植物给目前我国天然草地以及畜牧业带来的经济损失以及危害,针对疯草类有毒植物、乌头属有毒植物、橐吾属有毒植物、瑞香狼毒、醉马芨芨草、紫茎泽兰6种危害较为严重的有毒植物的毒理学与中毒病及其防治技术方面的研究进展作了概述,对未来在有毒植物中毒的防控方面提出几点建议,旨在为我国草原牧区放牧家畜有毒植物中毒病综合防控和健康养殖提供理论指导。     

饲用植物资源在我国天然草地上分布特征

我国饲用植物资源丰富，种类繁多，是草地资源的主要组成部分，但不同类群的饲用植物在草地上的地位和作用不同。根据全国草地资源调查研究资料分析，禾本科饲用植物是构成我国天然草地的主体，饲用植物价值最大；豆科饲用植物种类多、营养丰富，在草群中参与度低；莎草科饲用植物在高寒地区草地上占优势；杂类草数量多、分布广，除少数种类外，在草群中多为伴生种类。     

四川省甘孜州天然草地有毒有害植物种类及分布调查

1997～1999年对甘孜州天然草地有毒有害植物种类及分布进行了调查,主要有毒有害植物共计33科、81属、239种.通过调查,掌握了有毒有害植物的种类、分布、以及发生规律,可为有毒有害植物防除提供依据.     

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.     

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.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.