草坪草叶枯病病原鉴定

从典型叶枯病病斑中分离出 3种病原菌 ,经对其病原菌形态、培养性状和致病性等方面的测定表明 ,兰州市草坪草叶枯病主要致病菌为禾草离蠕孢 (Bipolarissarokiniaha) ,其次为狗牙根离蠕孢 (B .cynodontis)。禾草离蠕孢菌在不同品种草坪草中的潜育期不同 ,在感病品种ReblⅡ中的潜育期为 36h ,在抗病品种Raymond中的潜育期为 72h。     

13个草地早熟禾品种对3种根部病原菌的抗性评价

对13个草坪早熟禾品种分别接种茄类镰刀菌(Fusariumsolani)、立枯丝核菌(Rhizoctonia solani)、禾草离蠕孢菌(Bipolaris sorokiniana)3种病原菌,进行品种的室内抗病性测定,结果表明:早熟禾属的品种抗病性差异明显,在接种茄类镰刀菌的处理中,抢手股、浪潮、优异和蓝鸟4个品种的抗病性较好;在接种立枯丝核菌的处理中,巴润和午夜的抗病性最好;在接种禾草离蠕孢菌的处理中,康尼表现出较好的抗病性。     

不同黑麦草品种抗病性评价

通过对20个黑麦草品种自然发病调查,采用病级分类和系统聚类分析方法进行抗病性评价。结果表明,对锈病表现抗性和中抗的品种有10个和5个,分别占供试品种的50%和25%;对镰孢枯萎病表现抗性和中抗的品种有14个和4个,分别占供试品种的70%和20%;对灰梨孢灰斑病表现抗性和中抗的品种有14个和5个,分别占供试品种的70%和25%;对离孺孢叶斑病表现抗性和中抗的品种有14个和6个,分别占供试品种的70%和30%。多数品种对黑麦草4种病害抗性表现较好,可从黑麦草供试材料中选用优良抗病材料用于四川地区种植;也可从黑麦草供试材料中选择感病或高抗型品种进一步研究黑麦草抗病性机理。     

禾顶囊壳小麦变种对草坪禾草的致病性研究

应用人工接种法测定了禾顶囊壳小麦变种中国菌系对草地早熟禾、多年生黑麦草、匍茎剪股颖、高羊茅、硬羊茅和狗牙根等6种草坪禾草24个品种的致病性。结果表明,该菌对供试各草种都能正常致病,引起典型全蚀病症状。大多数供试品种的病根率和病根严重度都很高,属于感病类型,仅匍茎剪股颖的绿宝石品种具有中度抗侵入性和高度抗侵染性,高羊茅Shorter品种和硬羊茅参试品种具有中度抗侵染性。由于该菌引起的小麦全蚀病在我国分布广泛,可以提供大量菌源侵染草坪禾草,从而对草坪构成严重威胁。     

外源诱导物水杨酸对草坪型高羊茅弯孢霉叶斑病抗性影响的研究

在适宜弯孢霉叶斑病发病的条件下。对草坪型高羊茅热浪、黄金岛两个品种的植株喷施外源诱导物水杨酸后接种新月弯孢菌。结果表明：喷施水杨酸可以降低两个品种的弯孢霉叶斑病的发生。在平板培养中，水杨酸对新月弯孢菌分生孢子的萌发率及菌丝的生长均无明显的抑制作用，因此认为水杨酸处理后所试品种病情指数的下降是由于水杨酸处理提高了植株的抗病性，即所试品种产生了诱导抗病性而引起的；0．0l～0．1mM的水杨酸诱导处理诱抗效果达到50％以上，水杨酸诱导高羊茅抗弯孢霉叶斑病的最佳浓度为0．0lmM，诱导效果可达到70％以上；黄金岛的诱导抗性要好于热浪。诱导最佳间隔期为3d，诱导抗性持久期可达到15d。     

禾草对禾顶囊壳玉米变种的抗病性研究

利用人工接菌方法测定了10种草坪禾草,包括多年生黑麦草、高羊茅、紫羊茅、中华结缕草、硬羊茅、草地早熟禾、加拿大早熟禾、匍匐剪股颖、细弱剪股颖、狗牙根;13种禾本科牧草,包括一年生黑麦草、鸭茅、碱茅、扁穗冰草、沙生冰草、披碱草、老芒麦、杂交小米草、猫尾草、弯叶画眉草、无芒雀麦、百喜草、苏丹草;以及4种禾本科作物,包括燕麦、甜高粱、小麦、玉米对禾顶囊壳玉米变种的抗病性。结果表明,多数供试禾草对其具有免疫能力,多年生黑麦草、一年生黑麦草、草地早熟禾、小麦高度抗侵染;无芒雀麦和玉米具有中等程度的抗侵染能力,但抗侵入能力较差;高粱属的苏丹草和甜高粱中度感病,属于中感作物。多年生黑麦草和草地早熟禾品种间存在着抗病性差异,有免疫品种和高抗品种。     

引种草坪草的适应性评价及病害和草害

1997～1998年，对引自丹麦的草地早熟禾、黑麦草、高羊茅、羊茅、紫羊茅、匍匐剪股颖和白三叶等草坪草的品种在兰州市进行了适应性评价。观测、记载了草坪的成坪期、密度、盖度、颜色、质地、越冬率、越夏率、返青期、枯黄期、青缘期等性状；调查了病害的发病率，并对病株进行了病原物的分离、培养和鉴定，统计了各品种带菌率和真菌的分离率；调查了草坪建植与生长过程中的杂草种类和危害程度。结果表明：除Pichwick和Juventus黑麦草以外的所有参试品种均可在兰州地区种植。其中，白三叶的综合性状最好，具有质地柔滑、成坪较快、覆盖度高、枯黄期晚等特点；其次为ORNAMENTAL和SPORT2个混配型草种，成坪快，但抗病性较差；其余各品种建坪后表现好，但成坪速度较慢。草坪生长过程中的主要病害为交链孢叶斑病、离蠕孢叶斑病、德氏霉叶斑病、壳二孢叶枯病、壳二孢叶斑病、镰刀菌枯萎病和叶点霉叶斑病。苗期主要杂革为狗尾草和田旋花。     

几种真菌对3种常见冷季型草坪草的致病性测定

以我国北方常见的冷季型草坪草高羊茅(Festuca arundinacea)、多年生黑麦草(Lolium perenne)和草地早熟禾(Poa pratensis)为材料，将细交链孢(Alternaria alternata)、根腐离蠕孢(Bipolaris sorokiniana)、枝孢(Cladosporium herbarum)、新月弯孢(Curvularia lunata)、德氏霉(Drechslerasp．)、燕麦镰孢(Fusarium avenaceum)、锐顶镰孢(F．acuminatum)、尖镰孢(F．oxysporum)，腐皮镰孢(F．solani)和粉红粘帚霉(Gliocldium roseum)10种分离自草坪草的真菌接种，进行离体叶片的致病性测定。结果表明：细交链孢、根腐离蠕孢、德氏霉、腐皮镰孢、粉红粘帚霉和枝孢对高羊茅具有明显的致病性；根腐离蠕孢、燕麦镰孢和锐顶镰孢对黑麦草有明显的致病性；而仅根腐离蠕孢对早熟未有较明显的致病性。     

外源诱导物水杨酸对草坪型高羊茅弯孢霉叶斑病抗性影响的研究

在适宜弯孢霉叶斑病发病的条件下,对草坪型高羊茅热浪、黄金岛两个品种的植株喷施外源诱导物水杨酸后接种新月弯孢菌,结果表明:喷施水杨酸可以降低两个品种的弯孢霉叶斑病的发生。在平板培养中,水杨酸对新月弯孢菌分生孢子的萌发率及菌丝的生长均无明显的抑制作用,因此认为水杨酸处理后所试品种病情指数的下降是由于水杨酸处理提高了植株的抗病性,即所试品种产生了诱导抗病性而引起的;0.01～0.1mM的水杨酸诱导处理诱抗效果达到50%以上,水杨酸诱导高羊茅抗弯孢霉叶斑病的最佳浓度为0.01mM,诱导效果可达到70%以上;黄金岛的诱导抗性要好于热浪,诱导最佳间隔期为3d,诱导抗性持久期可达到15d。     

兰州大学草坪与绿地植物病虫害调查与养护技术

通过对兰州大学运动场草坪和绿地草坪病虫害调查，共发现由12种病原真菌引起的23种真菌病害，分别寄生于5属6种坪用和绿地植物。危害兰州大学草坪草早熟禾Poa pratensis病害3种、黑麦草Lolium perenne病害5种，高羊茅Festuca arundinacea病害2种、紫羊茅F．Rubra病害2种、苜蓿Medicago sativa病害6种及白三叶rifolium repens病害5种。其中主要病害有：禾草交链孢叶斑病Alternaria alternata，禾草根腐离蠕孢叶斑病Bipolaris sorokiniana，禾草新月弯孢叶斑病Curvularia lunata，禾草褐斑病Rhizoctonia solani，早熟禾德氏霉叶斑病Drechslera poae，苜蓿褐斑病Pseudopeziza medicaginis，苜蓿黑茎病Phoma medicaginis，苜蓿炭疽菌Colletotrichum medicaginis，苜蓿锈病Uromyces striatus，三叶草锈病U.trifolii及三叶草白粉病Erysiphe pisi和苜蓿白粉病E．Pisi。危害兰州大学草地的主要有害生物有2类：蛴螬类和蛞蝓Agriolimax agrestis。在调查基础上，提出了一些切实可行的病虫害综合防治技术措施。     

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.     

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.     

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.     

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