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黑龙江省西部半干旱区牧草引种筛选研究初报 总被引:5,自引:0,他引:5
对不同来源的20种牧草进行了两年的引种筛选试验研究,结果表明:豆科的肇东苜蓿、公农1号苜蓿、草原2号苜蓿和禾本科的无芒雀麦、林肯无芒雀麦、扁穗冰草、细茎冰草,在2001年极其干旱年份越冬率、产草量、抗逆性、分枝(分蘖)数、茎叶比都优于其它13个品种;而苜蓿品种国内的优于国外品种。由此认为,这7个牧草品种是黑龙江省寒冷干旱区、半干旱区建立人工草地、改良退化沙化草地的优良草种,可大力推广种植。 相似文献
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高寒牧区多年生人工草地混播组合试验 总被引:8,自引:0,他引:8
利用箭筈豌豆Vicia sativa、冷地早熟禾Poa crymophila、草原2号苜蓿Medicgao varia、沙生冰草Agropyron cristatum、无芒雀麦Bromus inermis、多叶老芒麦Elymus sibiricus、当地燕麦Ayea fatua在高寒地区进行了多年生混播草地建植试验.结果表明:在高寒地区建立人工草地,采取禾禾混播和禾豆混播,可明显提高草地产草量和牧草品质.表现优良的混播组合有草原2号苜蓿 无芒雀麦 多叶老芒麦、草原2号苜蓿 多叶老芒麦 冷地早熟禾、无芒雀麦 多叶老芒麦 冰草、无芒雀麦 多叶老芒麦 冷地早熟禾、草原2号苜蓿 多叶老芒麦 冰草. 相似文献
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苜蓿、无芒雀麦混播及单播草地产草量动态研究 总被引:8,自引:1,他引:8
探讨了科尔沁地区不同苜蓿品种 无芒雀麦混播草地产草量动态.结果表明:苜蓿在孕蕾~盛花期、无芒雀麦在拔节~初花期单播草地产草量增长最快,以后增长缓慢,到成熟期产草量达到最大.混播延长了种群产草量积累时间,混播草地最高产草量出现时期晚于单播草地.种群产草量的净积累主要发生在生育前期(苜蓿开花前).混播群落中3个杂花苜蓿 无芒雀麦群落的绝对生长率高于敖汉苜蓿 无芒雀麦群落.同种苜蓿混播与单播草地产草量快速积累期相同,不同种群产草量快速积累期有所差异.不同草地产草量的最大相对生长率出现时期相同,均出现在苜蓿孕蕾至开花期(无芒雀麦孕穗至抽穗期).播种当年混播草地产草量高于单播草地,以后二年混播草地产草量明显低于单播草地. 相似文献
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北方农区栽培牧草品种比较及营养品质研究 总被引:2,自引:0,他引:2
为了调整农业种植结构,于2000-2001年进行了36种牧草的引种栽培试验。通过2年试验,间比淘汰,筛选出13种豆科牧草(甘农1号杂花苜蓿、甘农2号杂花苜蓿、肇东苜蓿、和田苜蓿、草原1号杂花苜蓿、敖汉苜蓿、美国苜蓿、俄罗斯苜蓿、公农1号苜蓿、科学院苜蓿、龙牧2号沙打旺、苦草、白花草木樨),2种禾本科(林肯无芒雀麦、公农无芒雀麦)和1种蓼科(杂交酸模)牧草。结果表明:16种牧草适应北方春早春寒气候,抗旱耐寒能力强,其生产性能和营养价值高,达6134.0kg/hm^2。由此认为,筛选出的牧草品种是吉林省建立人工草地和调整农业种植结构的优质牧草。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献