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《当代畜牧》2016,(17)
为了解耐热冻干保护剂在猪繁殖与呼吸综合征活疫苗中的应用效果,将高致病性猪繁殖与呼吸综合征病毒(PPRSV)分别与耐热冻干保护剂和常规冻干保护剂进行配比、冻干,制备疫苗,分别将疫苗置2~8℃保存,定期测定其效价,同时进行37℃、25℃耐老化试验。结果显示,疫苗在2~8℃条件下保存24个月,耐热苗效价下降不超过0.5个滴度,常规苗效价下降超过3.0个滴度;37℃保存10d,耐热苗效价下降不超过0.5个滴度,常规疫苗下降超过2个滴度;25℃常温保存2个月,耐热保护剂疫苗效价下降不超过0.35个滴度,而常规苗效价下降超过2个滴度。试验结果表明,耐热冻干保护剂对病毒的保护效果明显优于常规冻干保护剂,具有良好的热稳定性。 相似文献
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为提高猪伪狂犬病活疫苗的保存温度,本实验应用响应面法(RSM)筛选并优化出猪伪狂犬病病毒(PRV)耐热保护剂最佳配方。结果表明:谷氨酸钠、L-精氨酸盐酸盐和D-山梨醇能够显著提高病毒对冻干环境的耐受能力,酶解酪蛋白、海藻糖、明胶、蔗糖和牛血清白蛋白显著性依次递减;以冻干后病毒保护率为响应值,响应面优化出最优配方为:谷氨酸钠2%、L-精氨酸盐酸盐2%、D-山梨醇2%、酶解酪蛋白7.6%、海藻糖1%、明胶4%、蔗糖15.2%、牛血清白蛋白2%。采用该配方进行验证试验,冻干保护率达到80.40%,经37℃保存7 d的耐老化试验及2℃~8℃保存24个月,3批疫苗病毒滴度分别下降0.55、0.62、0.47及0.47、0.51、0.41,证明该配方制备的疫苗具有良好的热稳定性。 相似文献
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《畜牧与兽医》2017,(1):94-97
旨在筛选出羊传染性脓疱皮炎弱毒苗的最佳耐热保护剂。通过初步筛选,选出符合本试验设计要求的3组保护剂A3、A6、C4,以羊传染性脓疱皮炎弱毒为对象,以保存环境、保存期长短、病毒损失量为参数,采用单因子试验对3组耐热保护剂进行优化,优选出对羊传染性脓疱皮炎弱毒苗耐热保护效果最好、且经济实用的耐热保护剂A6组。试验结果显示,使用A6保护剂的羊传染性脓疱皮炎疫苗在37℃保存3周,病毒含量下降0.4个滴度,常规疫苗下降2.4个滴度;25℃保存60 d,病毒含量下降0.3个滴度,常规疫苗下降2.2个滴度;4℃保存9个月,病毒含量下降0.4个滴度,常规疫苗下降3.8个滴度,说明A6可作为羊传染性脓疱皮炎弱毒苗良好的耐热保护剂。 相似文献
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应用鸡传染性支气管炎病毒(H52株)与不同耐热保护剂配方和冻干曲线进行筛选.结果表明:采用冻干曲线2和耐热保护剂WXS冻干鸡传染性支气管炎病毒H52弱毒疫苗效果最佳.试制耐热活疫苗3批,其各项检验均符合要求.耐老化试验表明:经过37℃放置10d的每羽份病毒含量下降0.6～0.8个滴度,每羽份病毒含量达104.7～105.1EID50.保存期试验表明:2～8℃保存24个月疫苗每羽份病毒含量下降0.4～0.6个滴度,每羽份病毒达104.1～104.3EID50.疫苗2～8 ℃保存24个月后效检抗体水平达到1:16～1:32.免疫持续期试验表明:免疫21日龄SPF鸡,6个月后血清中和抗体效价达到1:32～1:64.田间试验表明临床观察无不良反应,安全有效.特异性试验表明耐热活疫苗抗原性不变.耐热保护剂生物学和理化特性表明保护剂安全、稳定,室温保存期达3个月. 相似文献
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鸡马立克氏病火鸡疱疹病毒(耐热保护剂)活疫苗的研究 总被引：6，自引：2，他引：4
通过对不同保护剂基质与鸡马立克氏病火鸡疱疹病毒(HVT)相溶性的研究及冻干曲线的优化,成功研制出一种适宜HVT的耐热冻干保护剂。用其与相匹配的48h自然回温冻干曲线冻干的HVT耐热活疫苗,其病毒冻干损失比SPGA常规疫苗减少约50%,在2~8℃条件下可保存24个月,37℃保存10d病毒存活率达50.5%,而SPGA规程苗仅为31.6%。经约50万羽份的田间试验,证明安全有效并显示出良好的耐热性能,达到国外同类产品水平。 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