蝗虫微孢子虫防治青藏高原蝗虫对主要天敌种群数量的影响

以蝗虫微孢子虫为主的治理蝗虫的配套技术，在青藏高原蝗害治理中发挥了重要作用，能有效地控制蝗虫灾害，不污染环境，对自然天敌没有杀伤作用，保护了草地生态系统的生物多样性．特别是蝗虫自然天敌的生物多样性；而运用化学农药治理蝗虫，天敌被大量杀伤，破坏了草原生态系统的生物多样性，蝗灾发生的频率增加。     

生物技术对草原蝗虫的控制效果及应用前景

介绍了蝗虫微孢子虫Nosema locustae、绿僵菌Metarhizium anisopliae、印楝素（azadirachtin AZ）等几种新型生物防治技术在控制草原蝗虫中的应用及发展前景。蝗虫微孢子虫,是一种专寄生于蝗虫等直翅目昆虫体内的单细胞真核原生动物,防后45 d测定,感染率为50.6%,虫口减退率为73.4%。绿僵菌是一类昆虫病原真菌,防后7 d的防治效果为66.5%,防后12 d的防治效果为76.7%。印楝素,是从印楝Azadirachta indica种子中提取的高效杀虫活性物质,0.3%印楝素乳油在施药2 d后,防治效果达95%以上。应用蝗虫微孢子虫、绿僵菌、印楝素等生物防治技术防治草原蝗虫不仅防治效果较好,而且对人畜、植物安全,不污染环境;有持久控制害虫种群数量的作用,并可通过传播和繁殖,扩大受益面积,从而达到经济、安全、有效地控制害虫,减少虫害损失,保护生态环境的目的。     

2种不同剂型蝗虫微孢子虫防治草地蝗虫的药效研究

在青海省环青海湖地区通过采用蝗虫微孢子虫对草地蝗虫进行试验示范研究。结果表明，2种不同剂型蝗虫微孢子虫施药后30d，防治效果达到70％以上，说明施药当年，草地蝗虫的虫口密度中等或偏低时，2种不同剂型蝗虫微孢子虫控制草地蝗虫效果较显著，可达到可持续控制草地蝗虫种群密度的目的。     

甘肃农业大学草业学院吸引研究生优秀生源办法

甘肃农业大学草业学院现有草业科学，作物保护和草地生物多样性3个博士学位授权点，草业科学、植物病理学、农业昆虫与害虫防治、农药学、作物保护和草地生物多样性6个硕士学位授权点。根据甘肃农业大学2009年研究生招生政策，结合学院招生实际情况，特制订以下吸引研究生优秀生源办法。     

草地蝗虫成灾规律与可持续控制对策

草地蝗虫灾害严重发生由内在条件和外部因素造成。气候变化引起持续干旱，造成禾本科牧草植株矮小，草地裸露面积扩大，草原动植物的生物多样性受到威胁；由于大量使用广谱化学农药杀伤天敌，使草地蝗虫种群增长失控，形成暴发性灾害；与牲畜争食牧草，给畜牧业造成巨大损失。针对草地蝗虫成灾的原因和规律，提出了3点综合治理措施。     

蝗虫微孢子虫对青海省天峻县草原蝗虫的持续控制作用

采用蝗虫微孢子虫防治青海省天峻县草原蝗虫；第三龄盛发期用药，用药后3周，虫口减退率最低达60％以上；存活蝗虫的感病率最高位达61.1%；有效地控制草原蝗虫的严重发生；而且，微孢子虫病能在草原蝗种群中流行，持续控制草原蝗虫的为害。     

玛纳斯南山天然草地不同植被类型蝗虫群落组成及多样性

蝗虫是天然草原生态系统中的重要组成部分，了解草原生态系统中蝗虫群落的结构及多样性是揭示草原蝗虫成灾危害机制及其可持续治理的基础工作之一。近年来，国内对草地昆虫群落结构进行了部分研究工作，但对不同植被类型蝗虫群落结构组成及多样性方面的研究少。     

我国应用蝗虫微孢子虫治理草原蝗虫的现状及展望

本文综合论述了近年来我国草原蝗虫的发生和应用蝗虫微孢子虫的防治现状 ,同时对蝗虫微孢子虫的增殖和生产及微孢子虫的侵染和致病机理进行了剖析 ;初步论述了蝗虫微孢子虫病在田间的流行规律和传播机理以及持续控制草原蝗害的效果 ;针对蝗虫微孢子虫治理蝗害的特点和微孢子虫的应用前景以及配套新技术的开发利用进行了综合分析     

祁连山高山草地毒杂草侵入对蝗虫相对多度的影响

为研究祁连山高山草地毒杂草侵入对蝗虫群落组成、相对多度以及群落数量的影响,2008-2009年6-9月在野外调查基础上,对毒杂草(狼毒、甘肃臭草和披针叶黄华)侵入型草地和天然草地植被群落、土壤理化特性以及蝗虫多样性及群落数量进行调查分析。结果表明,毒杂草侵入显著降低草地物种丰富度、Shannon-Wiener指数和均匀度指数(P<0.05),植被群落高度和生物量明显增加(P<0.05);甘肃臭草侵入型草地土壤有机质和含水量最高,狼毒侵入型草地土壤紧实度和天然草地全N含量显著大于其他样地(P<0.05);毒杂草侵入影响蝗虫群落组成、降低物种多样性、改变物种相对多度。但蝗虫群落数量因杂草种类呈现较大差异,蝗虫群落数量因甘肃臭草侵入而降低、随狼毒和披针叶黄华侵入而增加。高山草地毒杂草侵入通过改变植被结构和营养价值、影响蝗虫土壤理化特性和栖息生境,而草地蝗虫群落组成、数量和多样性对此做出积极响应。该研究不仅为研究高山草地毒杂草型退化对昆虫以及无脊椎动物的影响提供参考,而且也为高山草地生物多样性维持和保育提供有益依据。     

微孢子虫对环境的抗性

虽然许多原生生物而不只是微孢子虫与昆虫间有致病性联系，但本综述仅限于微孢子虫是基于2个原因。首先，微孢子虫显然是寄生于昆虫的最重要的原生动物类群。其次，从Brook（1988）的综述以来，关于非微孢子虫的原生生物的信息增加得较少。     

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

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.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein