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1.
１９８８～１９９２年经过５年的研究确定放牧日和放牧频率对北美长叶沙茅「Ｃａｌａｍｏｖｉｌｆａ ｌｏｎｇｉｆｏｌｉａ（Ｈｏｏｋ．）Ｓｃｒｉｂｎ．」和胡生须芒草（Ａｎｄ＃颍铮穑铮纾铮? ｈａｌｌｉｉ Ｈａｃｋ．）总有机物质储藏的影响。处理由６月，７月，８月１０月，６月和７月，６月和８月或者６月，７月和８月的月中放牧周期组成。各处理间季节载畜量相同且均等地分成多个放牧周期。用一岁牛在同一草地上进行了连续  相似文献   

2.
人工草地绵羊放牧系统研究—载畜量试验   总被引：3，自引：0，他引：3  
通过监测划区轮物条件下的放牧系统中两种载畜量的牧草生长速度，草地现存量，绵羊采食量以及绵羊生产性能等有关指标的动态变化，探讨了高低两种载畜量对系统中牧草生长，草地利用和家畜生长三方面的影响。结果表明：低载畜量仅在羊毛产量，羔羊断奶及半岁体重等三项指标上显示出一定，它方面均无显著差异。草畜平衡分析结果表明，在本试验采用的两种载畜量下，系统中牧草全年供给量均大于家畜需求量，说明系统还有潜在生产能力。  相似文献   

3.
放牧绵羊的生物学效率   总被引：4，自引：0，他引：4  
王钦 《草业科学》1996,13(1):32-37
采用消化代谢试验方法，研究了放牧绵羊生物学过程的功能，试验结果表明，牧草的营养何价值随着粗纤维含量的增加而降低，其中每公斤牧草干物质中的可消化蛋白７、８、９、１０月分别为１０８．７４、７１．７１、５３．１７和３３．４４ｇ牧草蛋白的生物学效率相应是１６．６７％，１４．２９％，１４．４５％和５．７７％，依据系统功能，研究了提出了通过放牧管理－转移牧草或家畜，调节土壤，牧草和绵羊三者的关系，使其供求平衡  相似文献   

4.
对实际放牧率与绵羊采食各种干燥台地灌木茎的程度之间的关系进行了研究。南非干燥台地的农户与研究人员中有一个经验原则,即绵羊采食灌木的直径接近或小于2mm。这项假设已经历了3年的检验。对Pentzia spinescens和Rosenia humillis这两种最常见牧草品种,用游标卡尺测量了它们的新近被采食的茎直径。在估计现有载畜量时所使用的可食干物质的估计值是将刈割后的干物质分成可食与不可食物质两类为基础的。此分类标准为2mm。关于绵羊自由采食直径高达2mm的茎干的假设是不成立的。适口性差的品种其采食茎直径很少达到2mm,而适口性好的品种其采食茎直径通常高于5mm。已证明适口性差的品种被绵羊采食的茎直径平均为1.4～1.6mm。这个结果直接影响了估计干物质量来估算载畜量的方法。这个地区长期载畜量额定值为30hm~2/大家畜单位;基于放牧率试验所得的每公顷净收益资料,求得载畜量为33.4hm~2/大家畜单位。放牧率与被采食茎直径的关系求得的最佳载畜量为32.5hm~2/大家畜单位。这表明,通过检测被采食特定种的茎直径,可以确定载畜量范围或调整放牧率。  相似文献   

5.
红池坝人工草地放牧方式和放牧强度的研究   总被引：4，自引：0，他引：4  
王淑强 《草地学报》1995,3(3):173-180
在红池坝人工草地对放牧方式和放牧强度进行比较研究,同时对已给定的载畜量加以验证,以便制定该草地的最适放牧制度。研究结果表明,适于该地区的放牧管理制度是划区轮牧;各个阶段的载畜量与牧草生长速度之间的关系可用数学模型表示为:Y=179.5＋5.48X,在每公顷7.5个绵羊单位的载畜量下进行中度放牧强度可获得草地最大产草量,并保持其稳定。  相似文献   

6.
采用粪便显微组织学分析技术，分析了呼伦贝尔草原放牧绵羊冬季采食植物的种类组成，对不同牧草的喜食程度，并探讨了当地牧草资源的质量状况及改良草场，合理放牧等问题，研究表明，放牧绵羊冬季食物以禾本科植物为主，占７３．３％，豆科植物次之，占１１．６％菊科植物占第３位，为７．４％，其它科植物所占比例较小。  相似文献   

7.
饲草饲料规划技术及其应用的研究   总被引：1，自引：1，他引：0  
王淑强 《草业科学》1997,14(1):57-61
对饲草料规划的术语和关键技术进行了定义和分析，并对饲喂料规划技术在红池坝的应用进行了研究，结果表明，红池坝放牧草地的潜在载畜量为每公倾１０个羊单位，７月和８月应当于开始储备牧草，储备量为２４６０ｋｇＤＭ／ｈｍ＾２，同时指出牧草现存量是放牧管理的重要指标。  相似文献   

8.
载畜量调控是草地放牧系统优化的主要技术环节。在昆明小哨示范牧场设轻牧、中牧、重牧3个载畜量处理,对应的载畜量分别为每公顷0.74、1.52、2.24个牛单位。每个处理设3个放牧小区进行轮牧,轮牧周期3个月。每个月测定牧草的生长量、饲草现存量、饲草养分;6月和10月两次测定地下生物量。结果表明,随着载畜量的增加,草地牧草的生长量也随之增加,轻牧、中牧、重牧的年度累计生长量分别为8667、9486和10264kg/hm2。同一时间段载畜量越高,牧草现存量越低。枯草期牧草的粗蛋白含量随载畜量的增加而降低,粗脂肪的差异则不大。生长期3个载畜量的草地牧草的粗蛋白、粗脂肪等主要营养成分差异均不大。草地牧草的地下生物量主要集中在0～10 cm的土层中,10月份地下牧草根量呈现出随载畜量增大而增加的趋势。3个载畜量条件下的轮牧小区均没有出现草地退化现象。  相似文献   

9.
通过不同强度的放牧试验表明,不同的放牧强度对土壤表层含水量、植被特征和绵羊增重都有程度不同的影响。随放牧强度的增加,土壤表层（0-20cm）含水量、牧草叶层高度、多度呈下降趋势;草地地上生物量下降显著（P〈0．05,放牧羊只增重差异不显著,但单位草地面积的羊只增重重度放牧区和中度放牧区较轻度放牧区分别提高56．14％（P〈0．01）和23．26％（P〈0．05）。  相似文献   

10.
不同放牧率对混播草地牧草与羔羊生产的影响   总被引：2，自引：0，他引：2  
通过三种放牧率对混播草地牧草和羔羊生产的影响进行了研究。结果表明，随着放牧率的增加，牧草产量、叶面积指数明显下降（Ｐ＜０．０５）并使茎叶比显著减少（Ｐ＜０．０５）。放牧率的增大，羔羊个体生产速度显著降低（Ｐ＜０．０１），单位面积的畜产品产量依次为中组＞低组＞高组。并得出羔羊生长量与放牧强度及采食牧草干物质量存在密切关系，同时放牧率影响肉的品质，放牧率不同，草地系统生物学转化效率中组比低、高组高，且草地生产能力最大。由此得出，混播草地以中等放牧率为最佳。  相似文献   

11.
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   

12.
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   

13.
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   

14.
Tropical Animal Health and Production -  相似文献   

15.
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   

16.
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   

17.
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.  相似文献   

18.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
  相似文献   

19.
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.  相似文献   

20.
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  相似文献   

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