驼绒藜属植物研究现状及进展

驼绒藜属植物为旱生、超旱生优良饲草,粗蛋白质、氨基酸含量较高,适口性好,营养丰富,防风固沙作用强,在改良草地、防止草原“三化”及荒漠草原区发展畜牧业生产中具有重要作用.阐述了驼绒藜属植物解剖学与细胞学、种子生理、抗性生理、生物学、生殖生物学与生殖生态学研究等6个方面的国内外研究现状、进展及存在问题.     

驼绒藜属植物种子生理研究进展

驼绒藜属植物为多年生强旱生半灌木,是干旱荒漠草场的优势种或建群种,是半荒漠区草原较为珍贵的野生优良饲用植物资源之一。由于野生驼绒藜种子寿命较短,败育现象严重,因此,我国野生驼绒藜群落正在逐渐减少,这也制约了该植物资源的推广、发展和利用。就驼绒藜属植物种子发育生理、败育生理、贮藏生理、劣变生理、萌发生理等进行了总结,以期为驼绒藜属植物种子生产及推广利用等提供参考材料。     

野生华北驼绒藜种群衰退的生殖特性探讨与恢复对策

华北驼绒藜(Ceratoides arborescens)为中国特有旱生灌木,其营养丰富,抗逆性强,是生态建设和改良草地的优良植物;目前其野生种群退化严重,并存在严重的生殖障碍。基于笔者近年来对内蒙古野生华北驼绒藜种群生殖生态学方面研究的基础,分析了华北驼绒藜种群生殖生态学特征,进而探讨了华北驼绒藜种群退化的生殖和环境因素,最后提出华北驼绒藜种群恢复原理与技术。     

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随着气候干旱变化和重牧利用对草地的影响,我国北方草原退化日益加重,沙化的面积逐步扩大,严重破坏了自然生态环境平衡.研究适应北方干旱环境的旱生、超旱生植物资源,改良退化植被,恢复生态环境,是我国目前亟待研究的重要课题. 驼绒藜属[Ce ratoides(Tourn.) Gagnebin)]植物是干旱、半干旱地区草原植被类型中的重要植物,属旱生、超旱生半灌木,在荒漠和半荒漠化草原地区是马、羊、骆驼等家畜四季喜食的优良饲草.此外,该属植物还具有良好的防风固沙作用,被誉为沙漠中的"绿色卫士",是改良天然放牧草地最有前途的牧草之一.因此,驼绒藜属植物在改良草原及荒漠化防治中的应用研究具有深远意义. 驼绒藜属牧草是藜科一个最古老的属.全世界共有7个种,主要分布于北温带干旱、半干旱地区,世界分布范围较广,在欧亚大陆,西起西班牙、东至西伯利亚、南至伊朗和巴基斯坦都有分布.我国有4个种和1个变种,分别为:华北驼绒藜(Ceratoides arborescens)、驼绒藜(C.latens)、心叶驼绒藜(C.ewersmanniana)、垫状驼绒藜(C.compacta)和长毛垫状驼绒藜(C.compacta var.longipilosa),主要分布于内蒙古、甘肃、宁夏、青海、新疆和西藏等省(区).     

内蒙古驼绒藜属牧草生物学特性研究

驼绒藜属植物全世界有7种，主要分布于北温带干旱、半干旱地区。经多年调研及栽培测试．发现内蒙古驼绒藜属植物有3个种群，分别为华北驼绒藜、驼绒藜、内蒙古驼绒藜。介绍了内蒙古驼绒藜属植物牧草的生物学特性，以期为该属牧草的推广种植提供参考。     

内蒙古驼绒藜属牧草生物学特性研究

驼绒藜属植物全世界有7种,主要分布于北温带干旱、半干旱地区.经多年调研及栽培测试,发现内蒙古驼绒藜属植物有3个种群,分别为华北驼绒藜、驼绒藜、内蒙古驼绒藜.介绍了内蒙古驼绒藜属植物牧草的生物学特性,以期为该属牧草的推广种植提供参考.     

驼绒藜属植物研究

驼绒藜属植物是饲用价值较高的超旱生半灌木,有重要的生态利用价值.在查阅国内外对驼绒藜属植物研究利用的相关文献基础上,对该属植物的研究进展、分类、分布、生态作用等进行了分析和论述.针对生产中提出的种子短寿命、直播困难、生产利用缺乏等问题,介绍了内蒙古农牧业科学院驼绒藜课题组的具体科研思路和科研进展.一是针对种子短命问题,开展了驼绒藜转录组的分析和控制基因的定位研究,目前已获得20 G的数据和完整的驼绒藜叶片组织的转录组集合,测序结果与信息将用于后续的种子寿命相关技术研发,期待实现能够延长种子寿命的产品或新材料;二是在种子直播技术未得到解决的情况下,采用小面积育苗后大面积移栽方式,将广泛应用于林业苗木生产的小面积育苗技术应用于驼绒藜属植物;三是针对生态应用技术,把自主知识产权的驼绒藜品种应用在干旱地区、盐碱地以及矿区植被恢复3个类型地区推广利用,使得驼绒藜属植物在生态恢复中发挥更大的作用.此外,在驼绒藜属植物的营养价值评价研究方面,开展了驼绒藜属植物颗粒饲料制备和替代苜蓿营养饲喂肉羊的研究,期待开拓饲料资源的新途径.     

驼绒藜属植物研究

驼绒藜属植物是饲用价值较高的超旱生半灌木，有重要的生态利用价值。在查阅国内外对驼绒藜属植物研究利用的相关文献基础上，对该属植物的研究进展、分类、分布、生态作用等进行了分析和论述。针对生产中提出的种子短寿命、直播困难、生产利用缺乏等问题，介绍了内蒙古农牧业科学院驼绒藜课题组的具体科研思路和科研进展。一是针对种子短命问题。开展了驼绒藜转录组的分析和控制基因的定位研究，目前已获得20G的数据和完整的驼绒藜叶片组织的转录组集合，测序结果与信息将用于后续的种子寿命相关技术研发，期待实现能够延长种子寿命的产品或新材料；二是在种子直播技术未得到解决的情况下．采用小面积育苗后大面积移栽方式，将广泛应用于林业苗木生产的小面积育苗技术应用于驼绒藜属植物；三是针对生态应用技术，把自主知识产权的驼绒藜品种应用在干旱地区、盐碱地以及矿区植被恢复3个类型地区推广利用．使得驼绒藜属植物在生态恢复中发挥更大的作用。此外。在驼绒藜属植物的营养价值评价研究方面，开展了驼绒藜属植物颗粒饲料制备和替代苜蓿营养饲喂肉羊的研究．期待开拓饲料资源的新途径。     

驼绒藜属植物生态生物学特性及栽培技术研究

驼绒藜属植物属于耐寒、耐旱、耐贫瘠、耐风蚀、繁殖力强的喜沙半灌木。综述了驼绒藜属植物的生态生物学特性,并从采种与种子处理、地块的选择与整地、播种与育苗、草地的培育、苗期的管护等方面介绍了驼绒藜属植物的栽培技术。     

驼绒藜属植物生态生物学特性及栽培技术研究

驼绒藜属植物属于耐寒、耐旱、耐贫瘠、耐风蚀、繁殖力强的喜沙半灌木.综述了驼绒藜属植物的生态生物学特性,并从采种与种子处理、地块的选择与整地、播种与育苗、草地的培育、苗期的管护等方面介绍了驼绒藜属植物的栽培技术.     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -