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利用链烷烃测定放牧羊驼采食量及种类的研究 总被引:1,自引:0,他引:1
放牧动物的采食量及摄入牧草的种类,对于评定放牧动物的营养状况有着十分重要的意义。本文采用测定牧草和粪便中链烷烃含量的方法,以羊驼为试验动物,在意大利中部佩鲁贾附近的农场,测定了羊驼的采食量、牧草摄入种类。结果表明:利用链烷烃技术测定放牧动物的采食量和牧草的种类,具有较好的应用价值。 相似文献
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农牧交错区不同牧草时期放牧奶牛采食量与食性的研究 总被引:1,自引:0,他引:1
用饱和烷烃法对不同牧草时期放牧奶牛的采食量进行了测定.结果表明:放牧奶牛在牧草幼嫩期、旺盛期、枯黄期3期的采食量结果分别为:绝对采食量(kg/d)为11.54±0.66、13.83±0.55、5.75±0.32,采食量在牧草旺盛期时达到最高.采食组成幼嫩期以苔草为主、旺盛期以隐子草为主、枯黄期以赖草为主,这与草场植物的生长和奶牛的喜好有关. 相似文献
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用饱和烷烃法对不同牧草时期放牧奶牛的采食量进行了测定.结果表明:放牧奶牛在牧草幼嫩期、旺盛期、枯黄期3期的采食量结果分别为:绝对采食量为(11.54±0.66)、(13.83±0.55)、(5.75±0.32)kg/d,采食量在牧草旺盛期时达到最高.采食组成幼嫩期以苔草为主、旺盛期以隐子草为主、枯黄期以赖草为主,这与草场植物的生长和奶牛的喜好有关. 相似文献
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放牧家畜采食量是评价草地生态系统转化效率和动物生产力的主要参数,受草地植被生长情况、环境条件、放牧方式、家畜生理特征及其瘤胃内环境等因素影响。放牧家畜采食量的准确测定一直以来都是食性研究的难点和热点问题,关系到动物营养状态的评估、补饲策略的制定以及食性理论的探索。传统采食量估测方法大多基于观察法或放牧前后牧草生物量差值法,这些方法对动物的干扰较小,但是受技术本身和适用范围的限制,如未能估测单个动物的采食量,很难适用于大范围的采食量估测。链烷烃技术和近红外技术的出现为准确测定采食量提供了前所未有的机遇,不仅能克服传统测定方法的缺点,还在准确率、适用范围(圈养动物和放牧动物)等方面优势较为明显,但由于粪便回收率和数据库完整性等因素的影响,目前应用于生物多样性较高草地的放牧动物采食量估测尚有难度。在简要总结不同方法的原理和影响因素基础上,综述了差值法、内标法、链烷烃法和近红外法在放牧家畜采食量测定方面取得的最新进展及存在的问题,并建议多种方法结合可以准确测定放牧家畜采食量,以期为制定合理的草地生态系统管理策略和实现草地可持续生态服务功能提供新思路和启发。 相似文献
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温带常见牧草中饱和烷烃浓度模式研究 总被引:2,自引:0,他引:2
利用气相色谱仪测定了7种温带常见牧草表皮蜡质层饱和烷烃(N-alkane)的浓度,对同一牧草种不同生育期的饱和烷烃模式进行方差分析.结果表明,不同生育期牧草饱和烷烃浓度模式存在显著的差异.在生长季节,绝大多数牧草的C29或C31的浓度超过50 μg/g,可以应用双烷烃法来估测放牧家畜的采食量.主成分分析和方差分析的结果表明,除了老芒麦与披碱草或羊草在9月份出现重叠外,其它牧草的饱和烷烃特征模式在各取样时间均出现显著差异.因此,在温带草原上,应用饱和烷烃技术估测放牧家畜的采食成分是可行的. 相似文献
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放牧条件下鄂尔多斯细毛羊成年母羊四季牧草采食量测定 总被引:2,自引:0,他引:2
为了探讨鄂尔多斯细毛羊成年母羊四季放牧采食情况,实现鄂尔多斯细毛羊精准饲喂模式,采用饱和烷烃法对鄂尔多斯细毛羊成年母羊四季放牧采食量进行了测定。结果显示:鄂尔多斯细毛羊成年母羊春、夏、秋、冬四季放牧采食量分别为(2.24±0.15)kg、(3.32±0.23)kg、(1.60±0.21)kg、(0.93±0.14)kg;其中成年母羊以夏季采食量最高,显著高于(P0.05)春季和秋季,春、夏、秋3季均极显著高于冬季(P0.01)。提示:在放牧条件下,成年母羊应根据草场营养供给情况在冬季进行适当补饲。 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