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围产期奶牛蛋白质、能量和矿物质代谢旺盛,易造成钙流失增加和钙动态平衡失调,多发低钙血症包括亚临床低钙血症和乳热,而且与其他矿物质代谢紊乱和疾病相互作用和影响。低钙血症也可以进一步诱发围产期奶牛其他生理变化、临床后果和疾病,包括产乳热、酮病、胎衣不下、真胃移位、瘫痪、免疫功能抑制以及相关的传染性疾病和炎症等,严重影响奶牛的生产水平与健康状况。深入研究低钙血症及与其他疾病的关联可进一步揭示低血钙发生和发展潜在的分子机制以及对其他疾病的影响。本文综述了近年来在低钙血症奶牛血液生化指标的综合检测和观察、低钙血症的监测和诊断、生物标记物筛选以及与其他疾病关联的研究进展,为优化产前营养策略减少低钙血症发生率,以及产后钙的补充及治疗的综合选择提供有益的理论借鉴。 相似文献
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奶牛围产期是指产前三周(产前21天)至产后两周(产后15天)的时期,这一阶段由于奶牛的免疫力下降。而且组织内的矿物质浓度要求必须稳定在很窄的适宜范围内。因而各种传染性和代谢疾病(如产褥热、胎衣不下、子宫炎、真胃移位、乳房炎等)主要发生在这一时期,不同的调查结果显示。在美国5%~7%的牛只发生产褥热(Jordan和Fourdraine,1993),产奶量降低14%,产奶寿命减少3.4年(Block,1984),66%的奶牛产后患有亚临床型低钙血症(Beede,et,al,1992),每年给美国奶牛养殖业带来1.4亿美元的损失。我国高产牛群中27%以上的奶牛患有产褥热,82%以上的经产奶牛产后患有亚临床型低钙血症,所以为保持奶牛在围产期的健康以期获得理想的生产效益。围产期奶牛的营养及管理改变了以往产前低钙产后高钙的传统饲养理念。实验研究表明,当只有低钙日粮每天提供的钙不超过15克时对预防产褥热才具有非常明显的效果(Goings等,1974),而在现实生产中含钙量如此低的日粮营养师是很难或不可能配制出来的。 相似文献
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为筛选除血钙浓度之外的能有效诊断和监测亚临床、临床低钙血症奶牛的潜在辅助指标,本试验选取健康奶牛、临床和亚临床低钙血症奶牛各20头,采血后分离收集血清,分别检测矿物元素(Ca、P、Mg、Na、K)、能量代谢(Glu、NEFA、BHBA、TG)、肝损伤(AST、ALT、ALP和GGT)和炎性反应(IL-1β、IL-6、IL-2、TNF-α、HP和SAA)等相关指标。结果显示,临床、亚临床低钙血症奶牛血液K、Mg、Na、Glu和IL-2的浓度与血钙浓度呈显著正相关,而P、NEFA、BHBA、IL-1β、IL-6、HP和SAA的浓度与血钙浓度呈显著负相关;临床、亚临床低钙血症奶牛血液TG与血钙浓度无显著相关性。结果表明,亚临床、临床低钙血症奶牛均存在不同程度的矿物元素失衡、能量代谢紊乱、肝损伤和系统性炎症,矿物元素(Mg、Na、K和P)浓度、能量代谢指标(Glu、NEFA和BHBA)状态和炎性因子(IL-1β、IL-2、IL-6、HP、SAA和TNF-α)可以作为联合敏感指标表征奶牛低钙血症,该研究为进一步寻找有效诊断和监测奶牛低钙血症的辅助指标提供数据支持。 相似文献
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氨基酸螯合钙口服液对产后奶牛健康状况及乳品质的影响 总被引:1,自引:0,他引:1
本研究旨在探讨氨基酸螯合钙口服液及复方氨基酸螯合钙口服液对产后奶牛健康状况和乳品质的影响。选取某大型牧场产后奶牛,按照分娩顺序交替指定为对照组、试验Ⅰ组和试验Ⅱ组,对照组饲喂常规日粮,试验Ⅰ组灌服氨基酸螯合钙口服液,试验Ⅱ组灌服复方氨基酸螯合钙口服液,定时采集血样和乳样,用于分析血浆生化指标及乳品质,同时观察产后奶牛的健康状况。结果表明:与对照组相比,试验Ⅰ组产后奶牛血浆钙含量及乳汁中乳蛋白含量升高,血浆甲状旁腺素含量、亚临床型低钙血症、胎衣不下的发病率显著降低;试验Ⅱ组产后奶牛血浆钙、镁含量和乳汁中乳蛋白含量升高,亚临床型低钙血症、胎衣不下的发病率及乳汁中体细胞数显著降低,在产后第7天极显著提高血浆中降钙素含量,极显著降低低镁血症的发病率。结果提示,氨基酸螯合钙口服液及其复方口服液,对控制奶牛产后疾病、提高乳品质量具有较好的效果,且复方口服液的效果更理想。 相似文献
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选取2胎以上12头围产期奶牛,采用配对试验设计分成4组,从产前3周开始随机饲喂4种阴离子盐添加剂日粮(高钙高镁组、高钙低镁组、低钙高镁组和低钙低镁组),饲粮阴阳离子差(DCAD)值均为-6.5mEq/100 g DM.研究阴离子盐酸化日粮Ca2+和镁水平对奶牛血清离子平衡及生产性能的影响.结果表明,各试验组奶牛的干物质采食量(DMI)有不同程度下降(P>0.05).尿液pH在5.5~6.5变化(P>0.05).产犊当天、产后1 d和产后3 d,阴离子盐酸化日粮中钙水平对围产期奶牛血清Ca2+浓度有显著影响;产犊当天,阴离子盐酸化日粮中镁水平对血清Ca2+浓度有显著影响;产后3 d,阴离子盐日粮钙和镁互作对奶牛血清Ca2+浓度有显著影响.产犊当天、产后1 d和产后3 d高钙高镁组血清Ca2+浓度均高于其他3组,并显著高于低钙低镁组.产后1 d及产后3 d高钙低镁组和低钙高镁组血清Ca2+浓度也显著高于低钙低镁组.各试验组奶牛产奶量差异不显著. 相似文献
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许多奶牛产后发生胎衣不下、亚临床型子宫内膜炎或子宫内膜炎等生殖道疾病,主要原因是分娩后产道受损及子宫内膜表层自然损伤等导致的子宫内细菌感染。中性粒细胞是子宫先天免疫系统的重要组成部分,也是抵御子宫内感染的主要防线,产后中性粒细胞迅速流入子宫可以避免胎衣不下及子宫内膜炎等临床疾病。葡萄糖供应、低钙血症、酮症和炎性细胞因子丰度变化都会影响子宫的免疫状态,有效调节免疫反应以预防子宫疾病有利于围产期奶牛的饲养管理,降低生殖道疾病的发生几率。论文综述了影响先天免疫、生殖道炎症程度和持续时间的因素,探讨了围产期奶牛免疫功能调节的有效治疗方法,可为围产期奶牛产后生殖道疾病预防和科学饲养管理提供理论依据。 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