贵州喀斯特地区草地畜牧业发展优势与潜力分析

根据中国草地资源调查资料(农业部畜牧兽医司,1996)、贵州各市(州)年鉴、CNKI数据库及相关文献、贵州气象局提供的数据等为依据,对贵州各市(区)气候、天然草地面积、草畜承载量、石漠化面积等因子进行研究,分析了贵州草地建植的政策优势、气候地形优势、植物资源优势和草地资源优势。结果表明:1)贵州根据气候和地形优势,为建立多层次、立体、反季节性牧草提供了条件;2)贵州天然草地面积4.82×106 hm2,占土地面积的27.36%,可利用天然草地面积3.76×106 hm2,占总土地面积的21.34%,占天然草地面积的78.01%,成片草地面积493.38hm2,占总土地面积的0.28%,草地畜牧业的发展具有很大潜力;此外,人工草地的建立具遏制水土流失和石漠化、提高土壤肥力的功效;3)贵州喀斯特地区可利用冬闲田和陡坡种植牧草,作为备用草地,降低了牧草的季节性供应不均衡所带来的损失;4)草地畜牧业不仅涉及农学,还涉及到地理学、化学、生物学等多种学科,甚至能发展成为观光农业。     

青海省海东、海北地区草地资源产量与草畜平衡现状研究

利用青海省海东、海北两地区地面实测产草量,经过GPS定位,与MODIS植被指数数据建立天然草地资源产量反演模型,以及天然草地理论载畜量计算模型;同时,利用粮食等饲料作物和林地面积等资料,估算农林副产品的载畜量,结合青海省各地区季节放牧的实际情况,建立天然草地以及考虑补饲后的地区草畜平衡监测模型,分析两地草畜平衡状况。结果表明,1)海东、海北两地草地资源产量分别为195.30×10⁴和4590.92×10⁴ t,采食牧草产量分别为98.41×10⁴和2306.07×10⁴ t,天然草地实际利用率为50.4%和50.23%;2)两地区天然草地所能承载的最大载畜量为90.97×10⁴和856.18×10⁴只标准羊单位;3)综合天然草地和农业补饲各种因素后,海东、海北地区超载率分别为97.9%和-32.2%,海东地区超载较严重,海北未超载。     

衡量草地载畜平衡的尺度——平衡度

草地理论载畜量是评价天然草地的重要方法。计算草地理论载畜量可更准确体现草地的自然和经济特点,综合反映草地生产经营管理水平,为合理利用和科学管理草地资源提供理论依据。载畜量计算公式为: (1)暖季载畜量(亩/羊单位)=(暖季天数×日食量)/(暖季单位面积可食草产量)     

豫西地区天然草地分布及主要生产力研究

为准确掌握豫西地区天然草地的面积、产草量、载畜量及主要生产力状况,以2018年河南省天然草地资源调查数据为依据,采用遥感影像和野外实地调查方法,对天然草地的类型、分布、植被种类及主要生产力进行了研究.结果表明,豫西地区共有3个草地类及16个草地型,天然草地面积为16.13万hm2,占全省天然草地的30.89％,是河南省...     

中国西南地区的草地资源分析

根据中国草地资源调查资料(农业部畜牧兽医司,1996)、中国草业统计(2009)和相关文献,在实地调查的基础上,以中国西南地区的天然草地资源、冬闲田资源、林间草地为研究对象,分析了中国西南地区的草地资源状况。结果表明,1)西南地区天然草地总面积35.58×10⁶ hm²,占该区域土地总面积的32.59%,可利用草地面积29.04×10⁶ hm²,各省可利用草地面积占天然草地面积比例都在70%以上;2)按照以服务畜牧业为主要原则,将天然草地资源划为4个区域:热带湿润灌草丛区、亚热带湿润灌草丛区、亚热带半湿润灌草丛区和高原温带湿润灌丛草甸区;3)西南地区岩溶面积达52.23×10⁶ hm²,占土地面积的29.50%,共有292个岩溶县。石漠化面积达11.11×10⁶ hm²,占岩溶面积的21.27%,有88个石漠化严重县;4)西南地区农闲田可利用面积为961.46×10⁴ hm²,农闲田已利用面积为193.11×10⁴ hm²,占农闲田可利用面积的20.09%。冬闲田种草已利用面积共计118.58×10⁴ hm²,占农闲田可利用面积的12.33%,占农闲田已利用面积的61.40%。5)西南地区灌丛、疏林草地面积合计为1 894.84×10⁴ hm²,占草地面积的29.81%,占可利用草地面积的36.06%。     

青海省天然草地退化原因及治理对策

青海省有天然草地面积1.283 5×106km2,其中退化面积为5.0×107hm2,且退化严重.通过对全省天然草地的退化原因进行调查与分析,提出了相应的治理对策,为今后的草地建设和保护提供一定的参考.     

榆林市草地鼠虫害调查

1调查区概况 榆林市位于陕西省北部,地处毛乌素沙漠与黄土高原丘陵沟壑区之间,辖1区11县,总人口320万人,其中农业人口280万人,总土地面积4357800hm2,其中天然草场面积1．64×106hm2,占全市总土地面积的37．6％,占全省草地面积31．4％,可利用草场面积1．22×106hm2。有万亩以上集中连片的草场259块,面积6．68×104hm2。     

青海省海西州退化草地空间分布

据草地资源最新调查,海西州现有天然草地1191.77×104hm2,退化草地752.58×104hm2,因草地所在地区立地条件的差异和该区域草地所受的自然、人为因素影响的不同而有所差异。因此,退化草地在全州的分布格局也不尽相同。本文结合海西州草地资源调查数据,就海西州天然草地退化面积及退化程度进行了统计和比较。     

天峻县"黑土滩"现状及治理对策

天峻县地处柴达木以东、青海湖西北部,是一个纯牧业县.境内土地总面积2.5 723×106 hm2,其中可利用面积1.2 901×106 hm2,退化草场面积7.733×105 hm2,"黑土滩"面积1.213×105 hm2,全县平均海拔4 000 m以上.随着国家治理生态环境建设步伐加快,近年来,天峻县积极争取了荒山种草、草场封育、草原补播等项目,力求改善大面积的退化草地,恢复草场生产力,最终使天峻县畜牧业发展走上良性循环.     

从忠县草地资源论发展牛羊生产的途径

忠县地处四川盆地东部属川东平行岭谷的一部分,位于长江流域中段地区,人口97万。有丰富的草地资源和大量的农副稿秆,具有发展牛羊生产的物质条件。如何根据草地资源积极发展人工种羊,农副稿秆的利用和牛羊综合技术的推广,建立适度规模的家庭牧场,会大大地提高养牛羊的经济效益,促进忠县经济的发展。 1 草地资源的现状及特点 据1984年秋至1987年8月对全县草地资源现状进行了历时3年的实际调查。表明我县草地面积大、分布广,牧草种类多,产量高载畜潜力大,给牛羊生产提供了良好的条件,草地面积90.96万亩,其中可利用草地89.3万亩,占全县草地面积的98.2％。牛羊的主要饲养区域,以山地草丛、灌丛,农隙草地为主,多杂灌且要零星分布。草地载畜潜力大,牧草产量高。平均可利用面积草地亩产鲜草457～652千克,总产量为1.4亿千克,其中可利用牧草产量1.211亿千克,理论载畜量为12.76     

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