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1.
正优质牧草饲料改善了畜禽的日粮结构、节省了饲料,牧草中的营养成分及某些药用功效减少了畜禽药物的使用,在实现生态畜牧养殖中起到关键作用。本文从牧草品种选择、优质牧草的营养价值及在畜牧中的应用等方面进行综述,以期为牧草在畜牧养殖中的进一步应用提供依据。  相似文献   

2.
薛世明  匡崇义 《青海草业》2005,14(2):37-38,26
从云南的自然条件和社会发展需要出发,分析总结了云南草业科技今后的研究方向和发展趋势,主要是牧草种质资源的研究,牧草育种,牧草在种植业结构中的研究及应用,草地畜牧业可持续发展的研究和应用,生态环境治理,草坪业发展中的新品种、新技术的研究和应用等。  相似文献   

3.
安徽牧草资源多样性   总被引:2,自引:4,他引:2  
通过大量的实地调查和文献整理,初步查清了安徽牧草资源约有255种、2亚种、11变种,隶属于34科156属。根据粗蛋白和粗脂肪在干物质中的含量、有机物质消化率、抗性等方面的指标,对安徽现有重要优质牧草作了初步评述。同时,还对安徽开发利用牧草资源的有利条件,如优越的自然条件、优质牧草物种多样性丰富、抗性和兼用型种质资源丰富等方面作了初步分析。  相似文献   

4.
通过对牧草离体组织细胞染色体加倍育种中的诱导剂的介绍,进一步概述了诱变剂的浓度和处理时间、染色体加倍时的选材等因素对染色体加倍的影响及倍性鉴定技术,初步探讨了牧草离体组织细胞染色体加倍技术的研究概况,并展望了离体组织染色体加倍技术在牧草育种中的应用和发展前景。  相似文献   

5.
牧草种子生产中的潜在种子产量与实际种子产量   总被引:3,自引:0,他引:3  
本文介绍了牧草种子生产中的潜在种子产量(理论种子产量)、表现种子产量和实际种子产量(收获种子产量)等概念。分析了牧草实际种子产量与潜在种子产量之间的差距及主要原因,同时提出了提高牧草实际种子产量的措施。  相似文献   

6.
牧草次生代谢产物不仅具有抗氧化、抗病毒、消炎等生物活性,也能提高鸡的产蛋率,家畜的免疫力,改善肉品质。牧草次生代谢产物是近年来的研究热点,本文从牧草次生代谢产物的生物活性和在动物中的利用方面综述了其研究进展,从而为牧草次生代谢产物的进一步研究利用打下理论基础。  相似文献   

7.
中国牧草生物技术的研究现状和展望   总被引:2,自引:0,他引:2  
牧草在家畜业、环境保护和土壤保持方面都有重要的作用。因此,它比其他的农作物有较高的经济价值。由于牧草种类的复杂性和传统牧草育种遇到的困难,现在人们已经认识到生物技术手段在发展改良牧草品种中的巨大潜力。近来我国在应用生物技术进行牧草遗传改良方面已经取得了许多成就,这为遗传育种的成功提供了有效的策略。本文就近年来生物技术在牧草遗传改良方面研究进展及其应用进行全面的综述,内容包括组织培养、细胞工程、分子标记、基因工程和遗传转化系统;提出了目前我国牧草生物技术研究中亟待解决的一些问题和进一步发展方向,如提高牧草的抗性和品质,建立高效的转化系统,功能基因克隆,转基因牧草风险评价等。  相似文献   

8.
呼伦贝尔地区豆科牧草资源及其利用   总被引:3,自引:0,他引:3  
通过对呼伦贝尔地区豆科牧草资源的调查与研究,掌握了该地区豆科牧草种类,所占饲用植物中的比例,主要属种在群落中的地位和作用,营养价值和饲用特点等,同时还对豆科牧草的利用现状与开发潜力进行了探讨。  相似文献   

9.
牧草种子生产中的潜在种子产量与实际种子产量   总被引:25,自引:0,他引:25  
本文介绍了牧草种子生产中的潜在种子产量(理论种子产量)、表现种子产量和实际种子产量(收获种子产量)等概念。分析了牧草实际种子产量与潜在种子产量之间的差距及主要原因,同时提出了提高牧草实际种子产量的措施。  相似文献   

10.
轮作可以保证牧草的合理换茬,套种可以提高复种指数,混播可以促使两种或两种以上的牧草优势的互补。推广轮作、套种、混播等牧草高产栽培模式,可以最大限度地提高牧草的光能利用率,合理利用土壤中的水份和养份,提高牧草的生物学产量,降低杂草和病虫的危害,保证牧草的常年均衡供应。现向读者推荐六种牧草轮作、套种、混播高产栽培模式:  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.
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.
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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