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多不饱和脂肪酸在鱼类营养与饲料中的作用及其氧化稳定性 总被引：9，自引：0，他引：9
本文综述了国内外对n-6和n-3多不饱和脂肪酸在鱼类生长和健康中的作用，以及鱼类对日粮多不饱和脂肪酸的实际需求量，针对多不饱和脂肪酸易氧化的特性，还介绍了多不饱和脂肪酸氧化稳定性的研究现状，为在生产水产商品饲料过程中更好地选择多不饱和脂肪酸抗氧化剂提供参考。 相似文献
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多不饱和脂肪酸是所有细胞膜的重要成分,对机体的激素代谢和许多酶的活性起调控作用.动物和人自身不能合成亚油酸和亚麻酸,必需从外源食物中供给,因此对高多不饱和脂肪酸蛋的研究越来越受到关注.本文从鸡蛋中多不饱和脂肪酸的调控机制、多不饱和脂肪酸在鸡蛋中的富集、高多不饱和脂肪酸蛋的生产途径及研究应用现状等方面进行了简要综述,为其进一步开发研制提供参考. 相似文献
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多不饱和脂肪酸是所有细胞膜的重要成分,对机体的激素代谢和许多酶的活性起调控作用。动物和人自身不能合成亚油酸和亚麻酸,必需从外源食物中供给,因此对高多不饱和脂肪酸蛋的研究越来越受到关注。本文从鸡蛋中多不饱和脂肪酸的调控机制、多不饱和脂肪酸在鸡蛋中的富集、高多不饱和脂肪酸蛋的生产途径及研究应用现状等方面进行了简要综述,为其进一步开发研制提供参考。 相似文献
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对日粮多不饱和脂肪酸对蛋鸡体内脂肪代谢、血液中胆固醇和甘油三酯含量以及鸡蛋内胆固醇含量的影响进行了综述。机体脂肪代谢与日粮不饱和脂肪酸的种类和含量密切相关。日粮多不饱和脂肪酸参与体脂肪合成,影响体内极低密度脂蛋白和低密度脂蛋白的含量。机体血液中的甘油三酯和胆固醇含量随着日粮中多不饱和脂肪酸的种类和含量的变化而变化。鸡蛋中胆固醇的含量可以通过营养调控来减低,调节日粮中多不饱和脂肪酸的种类和含量可调控鸡蛋内胆固醇的含量。 相似文献
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《中国饲料》2020,(4)
脂肪酸如n-3和n-6多不饱和脂肪酸是重要的营养物质,特别是在冷休克或冷冻保存条件下,通过改变脂肪酸的形态和维持精子膜的完整性来提高雄性动物生殖性能。此外,多不饱和脂肪酸为前列腺素合成提供了前体,可以调节参与前列腺素和类固醇代谢的许多关键酶的表达。针对添加多不饱和脂肪酸的饲料研究表明,多不饱和脂肪酸能在冷冻期间维持精子活力、活性和生育能力,并改善各种动物的睾丸发育和精子形成。除了日粮脂肪酸种类和数量外,多不饱和脂肪酸添加到饲料或添加剂中的方式也非常重要,因为它对雄性反刍动物的精液质量有不同的影响。反刍动物日粮中添加多不饱和脂肪酸的限制是由于瘤胃微生物的生物氢化作用,使不饱和脂肪酸转化为饱和脂肪酸,导致多不饱和脂肪酸数量减少。近年来,许多保护多不饱和脂肪酸免受瘤胃生物氢化的策略得到发展。因此,本文从瘤胃代谢、生物学作用、对生殖的影响以及在雄性反刍动物中的应用策略等4个方面对多不饱和脂肪酸进行综述。 相似文献
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饲料中ω－3多不饱和脂肪酸的含量都较低，而ω－6多不饱和脂肪酸的含量却较高。鱼粉和鱼油中都富含ω－3多不饱和脂肪酸。它们是平衡ω－6多不饱和脂肪酸；ω－3多不饱和脂肪酸比的最有效的途径。而平衡的ω－6多不饱和脂肪酸；ω－3多不饱和脂肪酸比可提高家畜的健康水平和繁殖力。 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