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依据4种病毒生化指标设计了3种不同冻干曲线，配制10批“犬四联”弱毒疫苗分别进行冷冻干燥比较试验。结果表明：采用16h和22h冻干曲线冻干后的疫苗效价比冻干前下降1～2个滴度，抗原损失较大；采用20h冻干曲线冻干后的疫苗效价仅降低0．5个滴度，而且CPV和CPIV的血清抗体滴度(SN)也略高于用前两种冻干曲线冻干的制品，其冻干产品外观优于应用前两种冻干曲线的产品。因此选择总冻干时间20h的冻干曲线为“犬四联疫苗”较理想的冻干曲线。 相似文献
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王文成 《畜牧兽医科技信息》2002,18(12):7-10
冷冻干燥技术是生物学的一个重要应用技术,常用于生物制品的科研和生产中,以保持菌、毒种的生物学特性,稳定生物原料和半成品的生物活性,延长成品的有效期.近年来这一技术因“功能性食品“(Function food)的快速发展也被用于食品生产中.冷冻干燥具有二个优点:防止液体收缩,减少在干燥过程中由于浓缩可能引起的化学变化.但冷冻干燥的过程会对生物活性物质造成损伤,导致溶解度下降,活菌数减少和效价降低.为了尽量减少这种损伤,在冷冻干燥时加入适当的保护剂,以便微生物冻干后,有较高的存活率,同时还可使冻干的微生物在保存的过程中能耐受较高温度而减少死亡.…… 相似文献
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冻干保护剂可影响生物制品的质量、效价和稳定性，改变生物制品的生产工艺，提高产品预测能力并增大产品批次间的稳定性。耐热冻干保护剂有免疫活性但无药理活性，可在冻干和保存时维持疫苗的稳定性，初次干燥时在适宜的温度下疫苗不倒塌，企业低成本即可获取。 相似文献
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真空冷冻干燥技术,简称真空冻干技术,本技术可加工任何食品、药品,脱水后为冻干食品。冻干技术,是目前世界上最好的食品加工技术,可最大限度地保留产品的色、香、味、形和营养成分,包装后可在常温下五年不变质。复水后又好似鲜品。这是一个高科技、高附加值的食品开发项目。虽然它的生产成本较高,可是它的销售价格更高。因而效益相当好。外商在中国收购冻干食品的价格是每公斤干牛肉１３０元人民币,鸡肉１３０元的收购冻干食品价,人民币．元／干品．公斤）牛肉１３０、鸡肉１３０、胡萝卜１３０、白葱１２０、大蒜８０、菠菜２３０… 相似文献
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影响冻干乳酸菌存活性的相关因素 总被引：2，自引：0，他引：2
本文综述冻干乳酸菌发酵剂制备中相关因素对冷冻干燥和贮藏期间乳酸菌存活率的影响，包括内在因素、生长因素、非致死性处理、干燥介质、贮藏和复水等方面因素。 相似文献
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为应对畜禽产品贸易发展而造成的动物疾病全球传播和暴发的趋势,国家不断加大基础研发投入力度,本文综述了近些年国内兽用疫苗和冻干疫苗的发展状况,期共同发展. 相似文献
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鸡新城疫La Sota系新型保护剂冻干苗的保存期试验 总被引：1，自引：0，他引：1
鸡新城疫Ｌａ Ｓｏｔａ新型保护剂冻干苗、经１０￣１５℃保存试验,该疫苗效价的稳定性明显优于蔗糖脱脂乳冻干苗,１０￣１５℃保存４个月疫苗效价１００％合格,保存５个月２／３批效价仍合格;而蔗糖脱脂乳冻干苗,保存４个月,２／３批效价合格,保存５个月,疫苗全部失效。 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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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 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