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应用PCR诊断隐孢子虫病 总被引:10,自引:4,他引:10
应用聚合酶链反应( P C R)建立了一种诊断人及牛等哺乳动物隐孢子虫病的方法。试验采用甘油漂浮 G3 耐酸漏斗过滤法纯化隐孢子虫卵囊,以液氮冻融法制备模板 D N A,根据隐孢子虫 18 Sr R N A 序列设计 P C R 引物建立其诊断方法。该方法特异性强,可检出鼠隐孢子虫( Cryptosp oridium m uris)和小球隐孢子虫( C.parvum )卵囊;敏感性高,每克粪便可检出 400 个卵囊。初步应用结果表明,所建立的 P C R 方法适合于人、牛等哺乳动物隐孢子虫病的临床诊断和流行病学调查。 相似文献
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M. De Vos L. Che V. Huygelen S. Willemen J. Michiels S. Van Cruchten C. Van Ginneken 《Journal of animal physiology and animal nutrition》2014,98(4):609-619
Selection for hyperprolific sows, as a means of increasing litter size and profit, has resulted in an increased number of low‐birthweight (LBW) piglets. These LBW piglets might suffer from increased morbidity and mortality during the early neonatal period. In addition, they show reduced growth performance, meat and carcass quality, which leads to an important economic loss for the farmer in the post‐natal period. Therefore, nutritional interventions can be undertaken to prevent and rear LBW piglets. In the first part of this review, the preventive strategies at the sow level will be discussed. Approaches in preventing LBW piglets are to optimize the intrauterine environment via supplementing the sow during gestation. In the second part of this review, the interventions at the piglet level will be described. To increase the survival and growth rates of LBW piglets, one must focus on ensuring adequate colostrum and milk intake. Interventions include supplementing piglets, split nursing, split weaning and cross‐fostering. Additional interventions increasing the probability of optimal post‐natal food intake will be discussed. 相似文献
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Effect of intratesticular inoculation with Aujeszky's disease virus on genital organs of boars 总被引:1,自引:0,他引:1
Ten 8-10-month-old Belgian Landrace boars were intratesticularly inoculated with 500 TCID50 of a virulent Belgian Aujeszky's disease virus (ADV) isolate (75V19) in 0.1 ml volume. One control boar was similarly inoculated with phosphate-buffered saline solution. The genital organs of six inoculated boars were examined by virus isolation and immunofluorescence. In spite of high virus titers, the fluorescence in the testicles remained limited to a few small foci in the interstitial connective tissue and tunica albuginea at or close to the inoculation site. Neither virus replication, necrosis nor inflammatory lesions could be demonstrated in the epithelium of the seminiferous tubules. However, virus replication was regularly demonstrated in the serosa covering testicles, plexus pampiniformis, ductus deferens and tunica vaginalis. Virus was also isolated from the scrotal fluid. It is suggested that the serosa is the primary target tissue for ADV. The other four boars were inoculated to study the effect of ADV on semen. Severe morphologic alteration and lowered sperm cell concentrations were observed during several weeks after inoculation or until slaughter at 47, 53 and 58 days post inoculation. Virus was isolated from semen of only two out of four boars examined at 9 and 10 days post inoculation. 相似文献
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In vitro simulations of the gastric and small intestinal fermentation with varying doses of carvacrol, thymol, eugenol and trans-cinnamaldehyde and binary combinations thereof were carried out to calculate dose–response equations for the antimicrobial effect against the main pig gut flora components. Interaction effects were evaluated following the isobole method. In gastric simulations eugenol and trans-cinnamaldehyde showed clearly less inhibitory activity towards lactobacilli than carvacrol and thymol, which could also be observed in the small intestinal simulations. The minimum concentration for carvacrol, thymol, eugenol and trans-cinnamaldehyde in small intestinal simulations to reduce the number of total anaerobic bacteria compared to control with a probability of 99.7% was 255, 258, 223 and 56 mg/l respectively. This strong activity of trans-cinnamaldehyde was due to its effect against coliform bacteria; a dose of 104 mg/l gave a reduction of 1 log CFU/ml vs. 371, 400 and 565 mg/l for carvacrol, thymol and eugenol respectively. Few combinations demonstrated synergism; most mixtures showed zero interaction or antagonism. Only carvacrol + thymol was slightly synergistic. 相似文献
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Pantu Kumar Roy Ahmad Yar Qamar Xun Fang Ghangyong Kim Seonggyu Bang Mahanama De Zoysa Sang Tae Shin Jongki Cho 《Reproduction in domestic animals》2021,56(2):342-350
Oxidative stress is inevitable as it is derived from the handling, culturing, inherent metabolic activities and medium supplementation of embryos. This study was performed to investigate the protective effect of chitosan nanoparticles (CNPs) on oxidative damage in porcine oocytes. For this purpose, cumulus–oocyte complexes (COCs) derived from porcine slaughterhouse ovaries were exposed to different concentrations of CNPs (0, 10, 25 and 50 µg/ml) during in vitro maturation (IVM). Oocytes treated with 25 µg/ml CNPs showed significantly higher levels of GSH, along with a significant reduction in ROS levels compared to control, CNPs10 and CNPs50 groups. In parthenogenetic embryo production, the maturation rate was significantly higher in the CNPs25 group than that in the control and all other treated groups. In addition, when compared to the CNPs50 and control groups, CNPs25-treated oocytes showed significantly higher cleavage and blastocyst development rates. The highest concentration of CNPs reduced the total cell number and ratio of ICM: TE cells in parthenogenetic embryos, suggesting that there is a threshold where benefits are lost if exceeded. In cloned embryos, the CNPs25 group, as compared to all other treated groups, showed significantly higher maturation and cleavage rates. Furthermore, the blastocyst development rate in the CNPs25-treated group was significantly higher than that in the CNPs50-treated group, as was the total cell number. Moreover, we found that cloned embryos derived from the CNPs25-treated group showed significantly higher expression levels of Pou5f1, Dppa2, and Ndp52il genes, compared with those of the control and other treated groups. Our results demonstrated that 25 µg/ml CNPs treatment during IVM improves the developmental competence of porcine oocytes by reducing oxidative stress. 相似文献
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在讨论我国农业机械化发展的内在机制以及与城镇化关系的基础上,运用协整分析方法建立时间序列数据模型,经过格兰杰因果关系检验,验证农业机械化与城镇化之间的长期稳定关系,进一步建立误差修正模型探讨这种稳定关系在长期内与短期内的动态变化特征,并预测我国2020年农业机械化发展水平。结果表明,在长期内,城镇化率增加一个单位农业机械化水平将提高1.09个单位。但是,农业机械化对当期城镇化的推进反应是滞后的,而是反映在长期趋势上。预测显示,2020年我国农业机械化水平将达到67.45%。 相似文献