广东地区地毯草野生种质资源调查及生态特性研究

对广东地区地毯草野生种质资源的分布区域,群落组成以及生态特性等进行了调查和研究,结果表明:地毯草在广东的分布除了三连地区没有发现外,其他各地区都有分布。自然分布的地毯草群落主要分布于潮湿的河滩地、沟旁、路边、田坎、丘陵山地、山坡林地以及山谷地带,土壤pH 4.24~5.97。根据生境特点初步将地毯草野生种质资源划分为河滩草地型,疏林灌丛草地型和丘陵坡地型3种。地毯草群落结构中主要的优势植物种有竹节草、狗牙根、假俭草、双穗雀稗、两耳草以及百花地胆头等,其中以地毯草+竹节草+双穗雀稗和地毯草+竹节草+狗牙根两种群落组成类型较多。地毯草的耐旱、耐寒性一般,但具有非常好的耐淹、耐热、耐荫性以及耐贫瘠能力。地毯草丰富的群落特点和生态特性为培育有自主独立产权的地毯草新品种(品系)提供了有利的资源条件。     

中国竹节草野生种质资源调查及生物学特性研究

本研究调查了竹节草野生居群在我国的分布区域,并研究了其分布区气候及土壤、生境类型、群落组成及其形态学多样性,结果表明,1)在中国,竹节草分布于海拔10～1 000 m的热带以及北纬26°59′以南的亚热带地区,土壤pH值范围在3.50～7.43;2)其主要生境是河滩草地,路旁草地,向阳坡地等; 3)竹节草群落中主要优势植物种有地毯草、牛筋草、狗牙根、两耳草、假俭草和马唐属植物等;4)15个野生居群的竹节草植株形态特征及生物学特性有较大差异,尤其是茎节长度、匍匐茎的叶长、叶面积、直立枝的叶长和生长速度的变异系数在16%～24%;发现了一个野生株系在试验期内未抽穗结实;聚类分析结果也表明竹节草不同居群的外部形态性状有较大的变异,说明我国竹节草野生种质资源具有较丰富的遗传多样性.     

中国地毯草野生种质资源的形态学特征和生物学特性的变异研究

对我国地毯草野生种质资源形态学特征和生物学特性的变异情况进行了试验研究,结果表明我国地毯草野生种质资源的形态特征以及生物学特性在长期的自然驯化中已经出现了一些较大的差异,变异系数较大;其中叶面积、叶长、叶宽、节间距离、株丛株高、直立茎生长速度、匍匐茎生长速度以及分蘖速度等指标的平均变异系数分别达到20.36%、19.08%、8.64%、20.28%、28.31%、28.4%、13.08%和21.29%.通过对我国野生地毯草有关形态特征以及生物学特性各指标测定值的聚类分析,将我国地毯草野生种质资源材料初步划分为5大类群,这些不同类群的地毯草资源所具有的不同性状特点和较大的形态变异为不同功用优良草坪草的筛选提供了丰富的原始育种材料.     

中国地毯草野生种质资源耐旱性变异的初步研究

对我国不同来源地毯草野生种质资源抗旱性的研究结果表明,各供试地毯草的抗旱性与生境有着直接的关系,基本表现为分布于山坡地和路边等旱生环境中的地毯草,其抗旱性也相对较好,而那些在综合评判中表现为抗旱性较差的地毯草,大多是从河滩等湿生环境中采集到的材料。通过对土壤含水量、水分饱和亏缺指数、叶片保水力、游离脯氨酸含量和可溶性糖等与草坪抗旱有关的几个生理生化指标值的试验分析以及综合评判,将饶平地毯草初步确定为耐旱生态型。该生态型具有植株比较低矮,匍匐茎长短轴的差异不明显,叶片相对较小,匍匐茎生长速度和分蘖能力中等特点。     

中国地毯草野生种质资源的形态学特征和生物学特性的变异研究

对我国地毯草野生种质资源形态学特征和生物学特性的变异情况进行了试验研究，结果表明：我国地毯草野生种质资源的形态特征以及生物学特性在长期的自然驯化中已经出现了一些较大的差异，变异系数较大；其中叶面积、叶长、叶宽、节间距离、株丛株高、直立茎生长速度、匍匐茎生长速度以及分蘖速度等指标的平均变异系数分别达到20．63%、19．08%、8．64%、20．28%、28．31%、28．4%、13．08%和21．29%。通过对我国野生地毯草有关形态特征以及生物学特性各指标测定值的聚类分析，将我国地毯草野生种质资源材料初步划分为5大类群，这些不同类群的地毯草资源所具有的不同性状特点和较大的形态变异为不同功用优良草坪草的筛选提供了丰富的原始育种材料。     

广东南亚热带广泛种植的5种草坪草的生物学特性及抗旱性比较

通过对形态特征的观察和人工干旱胁迫试验,初步探讨了广东南亚热带地区广泛种植的狗牙根Cynodon dactylon,细叶结缕草Zoysia tenuifolia,地毯草Axonopos compressus,假俭草Eremochloa ophiuroides和广金钱草Deamodium styracifoli 5种草坪草在土壤持续干旱过程中的形态变化,并分析了这5种草坪草的干旱适应能力以及它们的抗旱能力与生物学特性之间的联系.结果表明,在持续干旱胁迫条件下,5种草坪草的抗旱能力依次为:狗牙根＞细叶结缕草＞假俭草＞地毯草＞广金钱草.     

狗牙根种质资源研究与改良进展

狗牙根(Cynodon dactylon(L.) Pers)既是应用最广泛的暖季型草坪草,也是优质牧草。我国拥有丰富的狗牙根种质资源,分布遍及黄河流域以南的广大地区,但我国的狗牙根种质资源评价与改良工作水平还很低。通过对狗牙根种质资源的分布、生物学特征、抗逆性、遗传多样性及育种等方面的研究进展进行系统概括和归纳,简要评述了狗牙根种质资源研究中存在的问题并展望其应用前景,以期为狗牙根种质资源的开发利用提供基础资料。     

使它隆对几种草坪草生理特性的影响

通过对狗牙根Cynodon dactylon,杂交狗牙根C.dactylon ×C. transvaalensis品种Tifgreen(328)、Tifway(419)、Tifdwaf以及海雀稗Paspalum vaginatum,两耳草P.conjugatum,百喜草P.notatum,地毯草Axonopus compressus,类地毯草A.affinis,金叶钝叶草Stenotaphrum secundatum,竹节草Chrysopogon aciculatus,假俭草Eremochloa ophiuroides,匍匐剪股颖粤选1号Agrostis stolonifera cv. Yuexuan No.1新品系叶面喷施使它隆溶液,测定了部分生理指标.结果表明,使它隆对百喜草安全,0.1%使它隆溶液可用于狗牙根、海雀稗、两耳草、金叶钝叶草及假俭草草坪;高浓度使它隆总体上使草坪草叶片叶绿素含量降低、膜透性增加、可溶性糖和可溶性蛋白含量增加.     

Na2SO4胁迫下狗牙根K+、Na+离子分布及其抗盐性的评价

通过对盆栽狗牙根(新农一号狗牙根)、喀什狗牙根、C-3(狗牙根品系)、矮生天堂草以0、0.4%、0.8%、1.2%、1.6%五个土壤盐浓度进行处理,对其K+、Na+离子变化情况做了研究.结果表明相同盐浓度水平下,狗牙根体内K+、Na+离子含量茎叶大于根系,茎叶是K+、Na+离子累积的主要部位;K+/Na+比茎叶大于根系,说明茎叶耐钠性大于根系;随着盐度水平的递增,新农一号狗牙根、喀什狗牙根、C-3狗牙根K+、Na+离子吸收选择性系数增大,新农一号狗牙根＞喀什狗牙根＞C-3＞矮生天堂草.由此初步认为,狗牙根抗盐性从大到小依次为新农一号狗牙根＞喀什狗牙根＞C-3狗牙根＞矮生天堂草.     

我国狗牙根种质资源研究进展

狗牙根(Cynodon dactylon)作为全球暖季型草坪革中坪用价值较高的草种之一,其生活力强,繁殖迅速,耐践踏,在我国不仅是应用广泛的优良草坪草之一,也是优良的固土护坡植物.制定科学的资源保护策略、促进其开发利用以及新品种的选育将具有重要的意义.本研究对我国狗牙根种质资源的用途、分布情况、遗传多样性以及育种进展进...     

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