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1.
内蒙古东北部天然牧草生物量与气候条件的定量关系   总被引：3，自引：4，他引：3  
赵慧颖 《草业科学》2007,24(3):8-11
通过相关分析,将牧草的整个生育期分为缓慢生长-积极生长-缓慢生长3个阶段.应用积分回归定量分析得出:牧草缓慢生长期正是返青-展叶(4月下旬-5月中旬)时期,温、水、光对牧草产量的影响呈正效应,每增加1个气象单位,依次增产牧草约18 kg/(hm2·℃)、10.5 kg/(hm2·mm)、16.5 kg/(hm2·h);牧草积极生长期正是牧草拔节-开花(5月下旬-7月下旬)时期,温度、日照基本满足牧草的生长发育需求,水分条件是主要矛盾,气温、降水量、日照每增(减)1个气象单位,依次减(增)产牧草约15 kg/(hm2·℃)、10.5 kg/(hm2·mm)、22.5 kg/(hm2·h);牧草缓慢生长期正是牧草灌浆-成熟(8月上旬-8月下旬)时期,此时光、水对牧草产量的影响呈负效应,气温对牧草产量的影响呈正效应,每增(减)1 ℃增(减)产牧草约12 kg/(hm2·℃).  相似文献   

2.
本研究以新苏2号苏丹草(Sorghum sudanense‘Xinsu No.2’)为研究对象,研究播种量与施氮量对夏播新苏2号苏丹草生产性能的影响。结果表明,当磷肥的施用量一定时,B1(播种量为22.5 kg·hm-2)和N3(施氮量为550 kg·hm-2)处理对株高的增长最有利;B1处理对主茎直径的增粗和单株分蘖数的增加最有利;B2(播种量为45 kg·hm-2)和N2(施氮量为415 kg·hm-2)处理对干草产量最有利,总干草产量分别达到19 200.0和19 744.5kg·hm-2;B3(播种量为67.5 kg·hm-2)和N2处理的粗蛋白增产效果最佳,总粗蛋白产量分别达到1 607.03和1 572.00 kg·hm-2。从干草和粗蛋白产量来综合考虑,B3(播种量为67.5 kg·hm-2)+N2(施氮量为415 kg·hm-2)是提高夏播苏丹草生产性能的最佳处理组合。  相似文献   

3.
降水对青海同德高寒草地牧草产量影响的积分回归分析   总被引：10，自引：1，他引：9  
利用积分回归的基本原理,并以青海省同德县巴滩高寒草地牧草产量为例,运用积分回归分析气象要素与牧草产量的关系,确定了青海省同德县巴滩高寒草地不同生育时段的降水对牧草产量的影响效应。结果表明,降水对高寒天然草地牧草产量的影响正效应为4月上中旬、5月下旬—7月上旬和8月下旬3个阶段,降水量每增加1mm,牧草产量最大增加138.2,80.1,53.8kg/hm2;负效应为4月下旬—5月中旬和7月中旬—8月中旬2个阶段,降水量每增加1mm,牧草产量相应最多减少23.1,43.7kg/hm2。  相似文献   

4.
种植密度和行距配置对紫花苜蓿群体产量及品质的影响   总被引：2，自引：0，他引：2  
以甘肃省主栽品种甘农3号紫花苜蓿(Medicago sativa cv.Gannong No.3)为研究对象,研究了甘肃荒漠灌区播种量(12,16,20和24kg·hm-2)和行距配置[3种等行距10、15和20cm,2种宽窄行距6行×10cm(窄)+40cm(宽)和6行×10cm(窄)+30cm(宽)]对其干草产量、茎叶比及营养成分的影响。结果表明,不同的行距处理中,20cm行距的苜蓿干草产量显著高于15、10cm和两种宽窄行距(P0.05);不同的播种量处理中,播种量为16kg·hm-2的苜蓿年总干草产量显著大于20、24和12kg·hm-2(P0.05)。播种量为16kg·hm-2、行距为20cm时,初花期苜蓿粗蛋白、粗脂肪、中性洗涤纤维、酸性洗涤纤维、钙、磷含量分别为21.89%、3.59%、33.69%、30.98%、1.34%、0.11%,其粗蛋白含量和年干草产量(32 841.71kg·hm-2)显著高于其它处理(P0.05)。从产量和营养品质综合考虑,该地区播种量为16kg·hm-2、行距为20cm是高产、稳产的最佳配置。本研究结果对苜蓿的栽培与管理有一定的指导意义。  相似文献   

5.
在新疆伊犁昭苏县境兵团76团猫尾草(Phleum pretense)栽培草地开展施氮研究.试验设4个施氮处理CK(0)、N1(90 kg·hm-2)、N2(180 kg· hm-2)、N3(270 kg·hm-2),分别在抽穗期、扬花期、结实初期、结实后期及收割后再生草进行饲草产量测定,并对各生育期饲草营养物质的含量进行测定分析,探讨不同施氨水平对猫尾草饲草产量和品质的影响.采用单固素方差法分析了不同施肥水平下猫尾草各个生育期饲草产量和营养品质各试验处理间的差异显著性.结果表明,施氮显著提高了饲草产量(P＜0.01),当施氮量为N3(270 kg· hm-2)时可收获干草7 133.6 kg·hm-2,比对照(4 952.2 kg·hm-2)高44.1％;施氮显著提高了牧草粗蛋白的含量(P＜0.05),当施氮量为N2(180 kg· hm-2)时饲草粗蛋白含量最高,为6.48％,比对照(4.43％)高出2.05个百分点;猫尾草生长高度随着施氮量的增长而增高;施氮量越高氮素利用效率越低,4个施肥水平下促进饲草产量增加最高的施氮水平是270 kg·hm-2,而就饲草营养品质的促进成效而言,最为显著的施氮水平是180 kg·hm-2.  相似文献   

6.
用1987～1990年乌鲁木齐牧业气象试验站天然牧草生育期和产量与气温、降水、日照时数观测资料,分析了气象条件对天然牧草生长及产量的影响,结果表明:不同品种牧草春季返青的温度指标不同,喜凉牧草为-1～-2℃,喜温牧草为4.6℃;黄枯期温度指标为6.3～9.1℃;热量条件可满足牧草生长发育及产量形成的需要;干草重与气象条件的相关性比鲜草重与气象条件的相关性好,不同要素中,降水量的相关性最好,积温居中,日照时数最差;用积温、降水量及日照时数可预测天然草场牧草干草重。  相似文献   

7.
利用1965~2015年曲麻莱地区月、光、温、湿气象资料和1990~2015年牧草资料,采用线性倾向估计、相关分析等方法分析了该地区光、温、水和牧草产量变化特征及其同期牧草产量和温湿因子之间相关性研究。结果表明:近51a来曲麻莱地区年平均气温以0.42℃/10a的速率呈极显著升温趋势,四季气温均呈极显著增加且秋季气温对年气温升温贡献率最大;年降水量和日照时数以11.6mm/10a和-18.9h/10a的速率呈不显著的增加和减少趋势,日照时数减少主要体现在春夏季;1990~2015年曲麻莱地区牧草产量以441.0(kg·hm~2)/10a速率呈显著增加趋势;牧草产量和同期温湿因子之间呈显著正相关,但年降水量变化对牧草产量的影响要大于气温对牧草产量的影响,冬季气温和夏季降水量对牧草产量的影响要大于其他各季气温和降水对牧草产量的影响。  相似文献   

8.
青海省兴海县天然草地牧草生长发育与气候条件的关系   总被引：1，自引：0，他引：1  
吴让  韩炳宏  韩通  周秉荣  李博  牛得草  傅华 《草业科学》2017,34(10):1991-1998
为了解青海省兴海县天然草地牧草生长发育及其与气候条件的关系,本研究基于青海省兴海县近11年的气象和牧草观测数据,较系统地分析了该区牧草返青、生长高度和产量与水热因子的关系特征。结果表明,春季多雨与春季干旱年份牧草返青期相差38d,牧草返青期提前或推迟主要与≥0℃初日的时间、当年3-4月份降水量和上年9-11月份降水量密切相关,牧草返青期降水的最佳气候模型为一次线性回归方程;牧草全生育期植物高度增加量与降水呈显著正相关关系(P0.05),而与气温呈负相关关系;另外,牧草生长高峰期6-7月份降水量每增加10 mm,鲜草增产225kg·hm~(-2)。因此,降水量是限制青海省兴海县天然草地牧草返青和生长发育的主要气象因子。  相似文献   

9.
运用区域历史回归分析的方法,选用1989~2005年6~9月期间三江源地区4个监测站点的牧草产量资料和降水资料,分析了牧草产量和降水量之间的相关关系。结果表明:降水量与牧草产量的相关系数显著性水平<0.05,并在此基础上建立了评估人工增雨量对牧草产量贡献的回归方程。计算表明:在三江源地区夏季(6~9月)通过人工影响,区域内每增加平均降水量10mm,即可在三江源地区增加区域平均牧草产量315kg/hm2。  相似文献   

10.
宁夏中部干旱带天然草地气候生产潜力研究   总被引：2，自引：0，他引：2  
依据宁夏中部干旱带同心县、盐池县等10个代表性气象台站36年(1975-2010年)逐旬气温、降水资料,基于Miami模型和Thornthwaite Memorial模型对宁夏中部干旱带1975-2006年间草地生产潜力作估算,并分析其变化规律,旨在为改良草地、植被恢复提供理论依据.结果表明:宁夏中部干旱带气候具有向“暖干化”变化的趋势,草地气候生产潜力年际变化范围为2668.56～7499.53kg·hm-2·a-1,气候生产潜力较大.当最高温度每升高或降低1℃,草地气候生产潜力增加或降低58.68 kg·hm-2·a-1;年降水量每增加或降低1 mm,草地气候生产潜力增加或降低18.64 kg·hm-2·a-1.宁夏中部干旱带各区域年降水量与气候生产潜力相关系数为0.984～0.997,成极显著线性相关,而年均气温与气候生产潜力无显著相关性.在进行天然草地补种植物时,应考虑该地的自然承受力,即天然草地气候生产潜力.  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

20.
Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.  相似文献   

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