高寒草甸草地牧草产量及其营养

高寒草甸草地是青海省草地畜牧业生产的主要物质基础。对所测高寒草甸草地实行全年封育，于7月、8月、9月测定草地地上生物量和营养物质。测定结果表明：①牧草产量以8月分最高，小嵩草甸干草产量可达43．7g/m^2，灌丛草甸可达109．9g/m^2；②与环湖地区相同类群牧草相比，牧草粗蛋白含量高，粗脂肪含量高，粗纤维含量低。牧草粗蛋白质含量随生长期的延长而降低，牧草粗纤维含量变化与之相反。牧草中锌含量缺额，硒、铜含量严重缺乏，必须对该区牲畜补饲硒、铜、锌制剂。     

鄂尔多斯天然草原牧草产量及营养成分研究

利用鄂尔多斯地区4个监测站2005~2016年的气象资料、天然草原牧草产量和营养成分监测数据,分析对比各个地区的牧草产量、营养成分以及两者和气象条件的关系。结果表明:乌审旗天然草原牧草的产量显著高于杭锦旗、鄂托克旗和鄂托克前旗。牧草营养成分最高在鄂托克前旗,其次为杭锦旗,最低的在乌审旗,相关分析结果显示,生长季的降水量与牧草的鲜重、干重和干鲜比均达到极显著的相关关系,相关系数分别是0.551,0.525和-0.355。牧草营养成分中的粗脂肪含量与生长季降水量呈极显著的负相关,日照时数与粗纤维含量呈现显著正相关,而与无氮浸出物的含量呈显著负相关。     

三江源区草地植被时空变化及其影响因子分析

为阐明近15a三江源区草地植被生长状况及其产量动态特征。利用该区2003～2017年生长季(6～8月)牧草产量及其同期气象资料,基于统计学方法较为系统地分析了该区生长季牧草产量变化趋势及其与同期气象条件的关系。结果表明,近15a来,三江源区牧草生长季年平均产量呈不明显的波动变化,其中高寒草甸和高寒草原牧草产量的最大值均出现在2010年,分别为3095.7kg/hm~2和1439.3kg/hm~2;最小值出现在2015和2006年,分别为2188.8kg/hm~2和491.4kg/hm~2。从产量的空间分布来看,三江源区牧草产量时空分布具有明显的异质性,自西北向东南依次递增。其中,东南部河南县牧草产量最大,局部地区甚至超过3500kg/hm~2;随着青海省三江源生态保护与建设规划项目的逐步实施,虽个别干旱年份草地植被生长状况较差,但整体呈稳定恢复状态。三江源区不同草地类型牧草产量之间差异显著(P≤0.05)。其中,牧草产量表现为:高寒草甸(2703.49kg/hm~2)全区(1775.64kg/hm~2)高寒草原(1013.68kg/hm~2)高寒荒漠、戈壁(383.33kg/hm~2)。相关分析结果显示,除高寒荒漠、戈壁对气温和降水不敏感外,高寒草甸草原对气温的敏感性更高,高寒草原对降水的敏感性则更强。由此可见,三江源区牧草生长季高峰期产量不是由单一气象条件决定的,而是气温和降水共同作用的结果。     

内蒙古天然草场牧草产量的气象估算模型

以内蒙古天然草场为研究区域,利用2004～2008年生长季牧草产量观测资料和能够综合反映光、温、水对牧草生长影响的气象条件指数,分析了内蒙古主要天然草场牧草产量与气象因子之间的关系,并分别建立了适用于不同草地类型(温性草原类、温性草甸草原类、低地草甸类、温性草原化荒漠类、温性荒漠草原类)的牧草产量气象估算模型.经过验证,所建产草量估算模型具有良好的估测能力,准确率较高,可以满足应用需要.     

晴隆县几种常用牧草营养成分测定结果与分析

优质牧草是发展草地畜牧业的重要饲草料资源,而牧草中的各种营养成分是维持草食性动物生长发育以及动物产品生产的物质基础和能量基础。牧草营养成分的测定直接关系着饲草料搭配的科学性、合理性,同时也保障了牧草营养价值的最大发挥。笔者通过试验测定晴隆县6种常用牧草的营养成分,结果表明,皇竹草粗蛋白含量最高,达到20.69%;马夫草粗蛋白含量最低,仅为9.12%;青蒿粗脂肪含量最高,达到2.73%;白刺花粗脂肪含量最低,仅为1.40%;多年生黑麦草粗纤维含量最高,达到31.18%;宽叶雀稗粗纤维含量最低,仅为22.59%。综合评定这6种牧草营养价值由高到低依次为:皇竹草、白刺花、宽叶雀稗、青蒿、多年生黑麦草、马夫草。这些牧草虽然营养价值有所差异,但均可以作为晴隆县饲养肉羊的优质饲草料来源。     

内蒙古典型草地不同时期土壤及植被养分评价

[目的]研究内蒙古典型草地不同时期土壤及植被营养状况的差异及变化特点，为内蒙古典型草地的合理利用、退化草地的恢复治理以及畜牧业的可持续发展提供参考。[方法]从内蒙古不同地区典型草原选取8个监测点，包括G1（鄂温克草原，温性草甸草原，呼伦贝尔市）、G2（乌拉特草原，荒漠草原，巴彦淖尔市）、G3（天然草滩，乌兰察布市）、G4（辉腾锡勒草原，五花草甸草原，乌兰察布市）、G5（科尔沁草原，温性草甸草原，通辽市）、G6（人工牧草种植地，赤峰市）、G7（乌拉特草原，荒漠草原，包头市）、G8（格根塔拉草原，荒漠草原，乌兰察布市）；于2020年牧草返青期、旺盛期、枯萎期分别从不同监测点样方中取0~20 cm土层土样及植物样品地上部分，测定土壤和植物中的常规养分含量；利用主成分分析法计算不同监测点不同时期土壤及植被营养水平的综合得分并排序。[结果]返青期、旺盛期、枯萎期土壤全氮含量均为G4监测点（辉腾锡勒草原）最高，极显著（P<0.01）高于其他监测点；旺盛期、枯萎期G7监测点（包头市境内乌拉特草原）最低。3个时期土壤有效磷含量均为G6监测点（人工牧草种植地）最高，显著（P<0.05）或极显著（P<0.01）高于其他监测点。3个时期土壤有机质含量均为G4监测点（辉腾锡勒草原）最高，极显著（P<0.01）高于其他监测点，G7监测点（包头市境内乌拉特草原）最低。返青期G6监测点（人工牧草种植地）的植被氮、磷、钾含量均为最高，极显著（P<0.01）高于其他监测点。旺盛期G8监测点（格根塔拉草原）的植被氮、钾含量最高，G6监测点（人工牧草种植地）的植被磷含量最高。枯萎期G3监测点（乌兰察布市境内天然草滩）的植被氮、磷含量最高，G4监测点（辉腾锡勒草原）的植被钾含量最高。3个时期植被粗纤维含量均是G5监测点（科尔沁草原）最高，G4监测点（辉腾锡勒草原）最低。土壤营养状况评分为：G4监测点（辉腾锡勒草原）3个时期评分均较高，G7监测点（包头市境内乌拉特草原）3个时期评分均最低；植被营养状况评分为：G2监测点（巴彦淖尔市境内乌拉特草原）及G6监测点（人工牧草种植地）返青期>旺盛期>枯萎期，其余监测点均是旺盛期>返青期>枯萎期。[结论]内蒙古典型草原的土壤及植被养分含量存在明显的时空差异。总体来看，草甸草原返青期、旺盛期、枯萎期土壤中养分综合评分较高，荒漠草原3个时期评分较低；不同草原类型的植被养分综合评分在旺盛期较高，枯萎期较低。     

冬季火烧对高寒草甸牧草产量及品质的影响

中国科学院海北高寒草甸定位站以围栏封育草地冬季火烧为研究对象、围栏封育未火烧草地为对照,对其产草量、牧草营养品质进行测定,探讨了冬季草原火烧对第二年牧草产量和品质的影响。结果表明:围栏封育草地冬季火烧之后第二年地上鲜草生物量显著高于围栏封育未火烧草地,火烧之后第二年地上枯草的积累量显著低于围栏封育未火烧草地。围栏封育草地火烧之后牧草粗蛋白含量比围栏封育未火烧草地粗蛋白含量显著提高;粗脂肪含量与围栏封育未火烧草地之间没有显著差异(P0.05)。围栏封育草地冬季火烧之后中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量比围栏封育未火烧草地显著升高,酸性洗涤木质素(ADL)含量与围栏封育未火烧之间没有显著差异。该研究表明草原火烧短期内对牧草产量和品质有一定的促进作用,加速了退化草地的恢复进程。     

桂西北地区不同地表处理方式改良草地的效果比较

笔者通过6种不同地表处理方式,对热研2号柱花草及纳罗克非洲狗尾草开展天然草地改良效果进行比较研究。连续2年分别对各处理改良草地牧草产量、牧草组分等指标进行测定,第2年取混合样进行营养成分测定。试验数据显示,使用化学除草+微耕地表处理方式改良草地,其干草产量、牧草粗蛋白及粗脂肪含量最高,而其粗纤维含量为最低。综合考虑干草产量、组分占比及养分等指标,化学除草+微耕是本试验中6个不同处理中最佳的草地改良地表处理方式。     

锡林郭勒天然草地营养成分评价

为揭示锡林郭勒草地天然牧草营养成分状况,合理开发利用草地生态资源,根据锡林浩特国家气候观象台2005－2011年天然牧草营养成分测定资料,应用主成分分析方法对锡林郭勒草地天然牧草营养成分进行了量化综合评价。结果表明,牧草饲料营养成分苏尼特左旗最高,乌拉盖管理区较低。荒漠化草原类型草地营养成分最高,其次为典型草原类型,草甸草原类型较低。     

山西白羊草灌丛草地牧草产量动态研究

对山西白羊草灌丛草地牧草产量动态三年的定位研究结果表明，白羊草灌丛草地牧草产量的季节动态规律较稳定，各年度动态曲线均呈单峰型，高峰值出现在８月份，峰期后牧草产量下降较缓慢；牧草营养物质的变化，生长前期粗蛋白含量较高，随生育期进展而逐渐减少，粗纤维含量则相反；粗蛋白质产量高峰期在８月，这与干草产量的高峰期正好吻合，此时正是该类草地利用的最佳时期。     

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 -