牧草常用的混播组合

地区混播组合东北华北、西北青藏高原南方中、高山地区南方低山丘陵区紫花苜蓿+羊草紫花苜蓿+无芒雀麦黄花苜蓿+无芒雀麦(或披硷草)白三叶+多年生黑麦草自三叶+多年生黑麦草+鸭茅+苇状羊茅+草地早熟禾白三叶+红三叶+多年生黑麦草+无芒雀麦红三叶+鸭茅+猫尾蕈白三叶+苇状羊茅白三叶+鸭茅+毛花雀稗卡松古鲁狗尾草+宽叶雀稗+马唐+鸡眼草牧草常用的混播组合     

牧草常用的混播组合

地 区混播组合北北、西北藏高原方中、高山地区方低山丘陵区紫花苜蓿+羊草紫花苜蓿十无芒雀麦黄花苜蓿+无芒雀麦(或披硷草)自三叶+多年黑麦草白三叶+多年黑麦草+鸭茅+苇状羊茅+草地早熟禾白三叶+红三叶+多年生黑麦草+无芒雀麦红三叶+鸭茅十猫尾草白三叶+苇状羊茅白三叶+鸭茅+毛花雀稗牧草常用的混播组合     

云贵高原人工草地混播组合的研究

红三叶(Trifolium pratense)、白三叶(Trifolium repens)、多年生黑麦草(Lolium perenne)、鸭茅(Dactylis glomerata)、无芒雀麦(Bromus inermis)、黑穗画眉(Eragrostis uigra)、紫羊茅(Festuca rubra)、草地早熟禾(Poapratensis)八种适宜当地生态条件的豆科及禾本科牧草组成三大类(刈牧兼用型复杂类、刈草型简单类、放牧型简单类)十二种不同的混播组合,在力求一致的试验条件下研究各混播组合植被类型的产量动态和植物群落内部各组分的变化规律,以了解各混播组合草地的生产能力和植物群落的稳定性(包括豆、禾比例在生产意义上的合理性及稳定性),并据此为当地筛选出建立人工草地的理想混播组合。结果表明,红三叶、白三叶、多年生黑麦草、鸭茅、紫羊茅、草地早熟禾在其参于的混播组合中,表现出较好的竞争性和互补性,可以当选为混播成员,而黑穗画眉、无芒雀麦在其参于的混播组合中逐渐被淘汰。联合分析结果表明,刈牧兼用型复杂组合总体上优于刈草型和放牧型简单组合,其中当选的组合有 V9(红三叶+白三叶+多年生黑麦草+紫羊茅)、V10(红三叶+白三叶+鸭茅+紫羊茅)、V12(红三叶+白三叶+多年生黑麦草);当选的刈草型组合有 V2(红三叶+鸭茅);当选的放牧型组合有 V6(白三叶+紫羊茅)、V5(白三叶+多年生黑麦草)。     

喀斯特地区三叶草混播草地群落组分20年动态

三叶草（Trifolium）混播草地群落持久性研究对喀斯特草地建设与石漠化治理具有重要意义。在威宁灼圃示范牧场开展的由白三叶（T. repens）、红三叶（T. pratense）、无芒雀麦（Bromus inermis）、紫羊茅（Festuca rubra）,分别加上多年生黑麦草（Lolium perenne）、鸭茅（Dactylis glomerata）、黑穗画眉草（Eragrostis nigra）、鹅冠草（Elymus kamoji）组成4个5组分混播草地,在绵羊适度放牧下测定牧前、牧后草地现存量,连续进行20年持久性研究。结果表明：时间及组合×利用时间的交互作用对所有混播组合影响极显著,而组合间产量差异不显著,其动态变化与年降水量的动态变化之间无显著的对应关系,但同物种在各混播群落中的生产力和稳定性差异明显,说明各组分之间存在显著的生态位互补和竞争共存关系。各物种中生产力与稳定持久性最好的是紫羊茅和白三叶,其次是多年生黑麦草和鸭茅,最差的是无芒雀麦和鹅冠草;而在草地建植初期表现最好的是多年生黑麦草和红三叶。     

喀斯特地区三叶草混播草地群落组分20年动态北大核心CSCD

三叶草(Trifolium)混播草地群落持久性研究对喀斯特草地建设与石漠化治理具有重要意义。在威宁灼圃示范牧场开展的由白三叶(T.rpens)、红三叶(T.pratense)、无芒雀麦(Bromus inermis)、紫羊茅(Festuca rubra),分别加上多年生黑麦草(Lolium perenne)、鸭茅(Dactylis glomerata)、黑穗画眉草(Eragrostis nigra)、鹅冠草(Elymud kamoji)组成4个5组分混播草地,在绵羊适度放牧下测定牧前、牧后草地现存量,连续进行20年持久性研究。结果表明:时间及组合×利用时间的交互作用对所有混播组合影响极显著,而组合间产量差异不显著,其动态变化与年降水量的动态变化之间无显著的对应关系,但同物种在各混播群落中的生产力和稳定性差异明显,说明各组分之间存在显著的生态位互补和竞争共存关系。各物种中生产力与稳定持久性最好的是紫羊茅和白三叶,其次是多年生黑麦草和鸭茅,最差的是无芒雀麦和鹅冠草;而在草地建植初期表现最好的是多年生黑麦草和红三叶。     

3种冷季型草坪草混播初期适宜比例初探

在大田条件下研究了草地早熟禾(Poa pratensis)、多年生黑麦草(Lolium perenne)和紫羊茅(Festuca rubra)不同混播比例组合对草坪综合质量的影响, 以期为北方地区草地早熟禾、多年生黑麦草和紫羊茅混播建植草坪提供实践依据。结果表明, 草地早熟禾、多年生黑麦草和紫羊茅混播建植草坪, 在多年生黑麦草比例为20%不变的情况下, 建坪初期, 草地早熟禾比例越小或紫羊茅比例越大, 则草坪密度越大, 质地越优, 草坪颜色越绿, 地下植物量越小, 地上植物量呈先减小后增大的趋势。综合各种草坪质量评价指标, 3种冷季性草坪草混播最佳比例为, 草地早熟禾:多年生黑麦草:紫羊茅=1:2:7。     

贵州南部混播草地几种建植因素最佳组合研究

选用苇状羊茅、多年生黑麦草、扁穗雀麦、蔬花雀麦、白三叶和紫花苜蓿等六种牧草,采用Ｌ９（３＾４）正交试验设计,探讨了在贵州南部地区生态条件下建立永久型优质人工混播草地最佳的草种组合、豆禾比例、播种量和播种方式。结果表明,草种组合是主要因素,播种量次之,用种比例和播种方式无明显影响;贵州南部地区优质永久型人工混播草地的理想草种组合是苇状羊茅＋多年生黑麦草＋扁穗雀麦＋白三叶（或紫花苜蓿）,豆科和禾本科的     

科尔沁地区禾豆混播人工草地生产特性分析

在科尔沁草原地区进行了不同草种和不同播种量组合的混播人工草地生产特性的研究。结果表明,无芒雀麦、苇状羊茅、披碱草、鸭茅、紫花苜蓿均具有较强的种间竞争能力,种间相容性较好;白三叶、草地早熟禾、猫尾草在苗期种间竞争能力较弱,幼苗死亡率较高,生长发育不良。在生产特性方面,草地早熟禾+鸭茅+猫尾草+紫花苜蓿+白三叶(组合Ⅰ)草地豆科牧草平均产量显著大于禾本科牧草产量(P<0.01);无芒雀麦+苇状羊茅+披碱草+紫花苜蓿+白三叶(组合Ⅱ)草地禾本科与豆科牧草产量差异不显著(P>0.05)。在全年总产量中,组合Ⅱ的禾本科牧草产量显著大于组合Ⅰ(P<0.05)。在本试验条件下,适宜的混播组合是:无芒雀麦占40.3%,苇状羊茅+披碱草占32.9%,紫花苜蓿占26.8%,总播种量37.3kg/hm2,全年干草总产量可达8580.12kg/hm2,其中禾本科牧草占50%左右,适合于放牧刈割利用。     

几种混播绿化组合对高等级公路边坡防护效益的研究

试验将3种混播组合对高等级公路边坡的防护效益进行了初步研究.结果表明:混播组合方案1(红豆草60%+无芒雀麦20%+多年生黑麦草20%)的防护效果最好,减少径流82.6%,减少冲刷90.1%;其次是混播组合方案3(多年生黑麦草40%+草地早熟禾20%+匍匐翦股颖20%+紫羊茅20%),减少径流80.9%,减少冲刷80.9%;而以混播组合方案2(小冠花70%+多年生黑麦草30%)的防护效果最差,减少径流76.4%,减少冲刷73.5%.     

几种混播绿化组合对高等级公路边坡防护效益的研究

试验将３种混播组合对高等组公路边坡的防护效益进行了初步研究。结果表明，混播组合方案１（红豆草６０％＋无芒雀麦２０％＋多年生黑麦草２０％）的防护效果最好，减少径流８２．６％，减少冲刷９０．１％；其次是混播混合方案３（多年生黑麦草４０％＋草地早熟禾２０％＋匍匐煎颖２０％＋紫羊茅２０％），减少径不充８０．９％，减少冲刷８０．９％；而以混播组合方案２（小冠花７０％＋多年生黑麦草３０％）的防护效果最差，减少     

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