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转基因动物在动物营养研究中的应用 总被引:5,自引:0,他引:5
本文综述了转基因动物在动物营养中的应用。包括两个主要部分,一是用转基因动物做模型,研究外源基因对动物生长和代谢的调控作用,说明外源基因对动物生长速度、饲料利用率及其胴体的组成均有影响。与此同时,还可以导入新的代谢体系中的主要基因,使动物本身获得对某些必需物质的合成能力,从而达到提高生产性能的目的。另一部分是日粮的营养成分对动物某些基因表达的调控作用,从基因表达水平说明营养成分对动物某些物质的合成、代谢的调控作用。这两个方面都为在分子水平上研究动物营养学提供了有效的手段和方法。 相似文献
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《中国兽医学报》2016,(12):2160-2165
为探讨外源pGH基因对转基因猪繁殖性能的影响及其在F1代中的遗传情况,对转pGH基因长白猪与普通长白猪繁殖性能的各项指标进行了测定和比较,并对转基因猪F1代仔猪进行了外源基因的检测。结果显示,除转基因母猪F1代仔猪断奶个体质量差异显著(P0.05)外,转pGH基因猪与非转基因猪繁殖性能其他指标均差异不显著;转基因公猪和转基因母猪F1代仔猪转基因阳性率分别为50.00%和47.83%,外源pGH基因对转基因猪的繁殖性能未产生显著影响,并可遗传给下一代。本研究为规范合理选育转pGH基因猪提供了理论依据,为进一步研究节粮型高瘦肉率转基因猪及其在实际生产中的应用奠定基础。 相似文献
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水稻是世界主要的粮食作物之一,同时也是重要的饲料原料.近年来国内外研究机构培育出数种转苏云金芽孢杆菌(Bacillus thuringiensis,Bt)基因水稻,可有效杀灭二化螟、三化螟、稻纵卷叶螟等虫害,减少水稻种植过程中农药的使用,提高水稻产量.由于水稻是人类主要的粮食作物,转Bt基因水稻的安全性受到广泛的关注.截至目前尚未有确切证据证实转基因水稻存在饲用安全性问题,但仍需对其长期饲用结果进行持续监控.作者现就转Bt基因水稻的发展、潜在风险和安全评价方法,营养价值、毒理性,对动物生长、免疫、肠道微生物的影响,以及外源基因和外源蛋白的残留等方面进行简要综述. 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