中国部分重点地区牛结核病的γ-干扰素试验流行病学调查

为调查部分省份牛结核病(bTB)的流行情况,我们在山东等14个省份34个历史上疫情较重的县共129个场户采集牛全血2 201份,采用CO2培养箱或蜡罐方法进行bTBγ-干扰素检测,结果显示样品的个体阳性率为6.4%,群阳性率为42.6%。饲养模式对bTB感染影响的统计显示较大规模场的个体阳性率(6.9%)和群阳性率(60%)均高于散养户(分别为5.7%和35.6%)。而牦牛样品的检测结果均为阴性。5个牛群的禽型PPD阳性统计结果显示牛型PPD阳性率越高,则禽型PPD阳性牛在牛型PPD阳性牛中的所占比率越低。在所有阳性牛群中,阳性率≥10%的牛群所占比例高达81.8%(45/55),bTB感染呈现出一个"群发性"的特征。     

丙谷胺对产蛋鸡摄食行为及内分泌的影响

选用35周龄伊莎蛋鸡8只,分别安装慢性颈静脉血管插管.实验采用自身对照法,对照期饲喂基础日粮,丙谷胺期在喂料前填喂丙谷胺.应用摄食行为计算机监测系统(FIDAS系统)记录各个实验期产蛋鸡喂料后4h内的采食行为数据,并测定有关血液生化指标.结果显示,实验期(填喂丙谷胺后)与对照期相比较,产蛋鸡午前(8:00～12:00)与午后(13:00～17:00)4 h内摄食量分别增加27.69%与30.41%(P＜0.05),摄食时间分别降低15.67%与3.75%,摄食餐数分别增加12.32%与27.2%(P＜0.05);血糖水平分别降低5.44%与18.03%(P＜0.01),瘦素水平分别升高2.59%与7.19%,胰岛素水平分别升高33.09%(P＜0.05)与24.5%(P＜0.05).提示丙谷胺能够促进蛋鸡摄食,并影响有关内分泌激素的水平.     

Effects of partial removal of cytoplasmic lipid on survival of vitrified germinal vesicle stage pig oocytes

This study was designed to investigate whether the partial removal of cytoplasmic lipid from immature pig oocytes prior to vitrification had any positive effects on subsequent maturation, fertilization and early development. Oocytes at the germinal vesicle stage were partially freed from cumulus cells and centrifuged, and then polarized cytoplasmic lipid was removed by micromanipulation. When cultured for 44-48 h, significantly fewer of the centrifuged oocytes reached metaphase II (M-II) than did the non-centrifuged oocytes (approximately 53% vs approximately 68%, respectively); however, no further reduction in the M-II rate was observed when centrifuged oocytes were then delipated prior to culture (approximately 47%). To evaluate their sensitivity to the equilibration and vitrification solutions containing ethylene glycol, non-centrifuged, centrifuged, and delipated oocytes were cultured continuously for several minutes in those solutions, then washed and cultured further; no significant differences in the M-II rates (approximately 20-27%) were observed among the three treatment groups. When oocytes were vitrified and then warmed, significantly more delipated oocytes reached M-II in culture (approximately 15%) than did the non-delipated oocytes, whether centrifuged or not (approximately 4% in each group). When delipated, vitrified and matured oocytes were microsurgically injected with frozen-thawed spermatozoa, approximately 39% were activated and male pronucleus formation was observed in approximately 40% of activated oocytes; none developed beyond the 4-cell stage. These results show that maturation in vitro of vitrified pig oocytes can be promoted by partial removal of cytoplasmic lipid prior to vitrification and that the vitrified oocytes can be fertilized, although the embryonic development obtained in this study was limited.     

肉种鸽繁殖性能低下的原因与对策

在进行肉鸽强制配对过程中，由于饲养人员缺乏基本的雌雄鉴别方法，将两只雄鸽配在一起，配对后长时间不见产蛋。这种情况在种鸽初次配对时出现较多。种鸽配对后要做好产蛋记录，一般配对后7～10天就会产蛋，如超过1月仍未见产蛋，要进行重新鉴定性别，重新配对。肉鸽性成熟后雌雄鉴别并不困难，主要通过性行为表现和耻骨特征来进行区分。雄鸽进入发情期后发情明显，追逐雌鸽，发出“咕咕”的叫声，并向雌鸽频频点头示爱。触摸耻骨厚硬，两耻骨间距窄或闭合，耻骨到胸骨末端距离窄，表明腹部容积很小。雌鸽发情不明显，受到雄鸽追逐，无叫声，到处躲藏，耻骨薄软，两耻骨间距宽，     

鸡沙门氏菌脉冲场凝胶电泳分型研究

为应用脉冲场凝胶电泳(PFGE)从分子水平上对禽源沙门氏菌之间的差别进行分析和研究,本研究采用自动微生物鉴定仪对12株疑似鼠伤寒沙门氏菌和15株疑似鸡白痢沙门氏菌进行了鉴定.以限制性核酸内切酶Xba I对其全基因组DNA进行酶切、PFGE分型,Info Quest FP聚类分析软件对电泳结果进行分析.结果显示,共鉴定出11株鼠伤寒沙门氏菌、1株圣保罗沙门氏菌、6株阿姆斯特丹沙门氏菌、5株亚拉巴马沙门氏菌、1株鸡白痢沙门氏菌、2株纽波特沙门氏菌和2株肠炎沙门氏菌,一共分为12个PFGE型.实验结果表明,江苏地区存在有不常见的沙门氏菌血清型,同种血清型之间的基因型差别较小(相似值为0.85～1),不同血清型之间差别较大(相似值为0.45～0.70).PFGE能从分子水平上对禽源沙门氏菌的基因组DNA进行分型.     

生物法处理养殖污水中氨氮的研究进展

综述近几年生物方法处理养殖污水中氨氮的研究进展及实际应用,并对大规模处理养殖污水方面提出了一些思考和展望,期望在今后的研究工作中能够探索出高效率、低成本、无二次污染的生物方法处理养殖污水中的氨氮.     

水貂阿留申病毒的分子生物学研究进展

从水貂阿留申病毒(ADV)基因组特点出发,就阿留申病毒的分子生物学研究进展作以简单综述。     

浅谈如何培养缉毒犬在搜毒工作中的自信心

<正>缉毒犬在搜毒工作中的自信心是指训犬员在使用缉毒犬的相关场所对搜索对象进行搜毒活动时,缉毒犬所表现出的积极、主动、细致、持久的强烈渴求发现毒品的心理状态,以及由此心理状态引发的一系列搜索活动。     

过瘤胃氨基酸在奶牛生产中的应用

本文综述了过瘤胃氨基酸的概念、稳定性、保护效果的测定方法及过瘤胃氨基酸对奶牛生产性能的影响和影响过瘤胃氨基酸效果的因素。     

结缕草种子打破休眠过程呼吸途径的研究

采用呼吸抑制剂测定了结缕草休眠与打破休眠种子在发芽过程中的各个呼吸代谢途径－糖酵解呼吸途径（ＥＭＰ）、三羧酸循环呼吸途径（ＴＣＡ）、磷酸戊糖呼吸途径（ＰＰＰ）的呼吸速率及其占总呼吸速率的比例，结果表明，休眠种子的总呼吸速率显著低于打破休眠种子的总呼吸速率，造成这种差异的原因是磷酸戊糖途径及三羧酸循环途径的呼吸速率低，这是休眠结缕草种子不能发芽的原因之一。