胎间隔和交配间隔时间对昆明小鼠繁殖性能的影响

在昆明(KM)小鼠的繁殖生产中,胎间隔和交配间隔时间需随着实验动物需求的阶段性变化进行调整,其间隔时间过长可能会造成繁殖性能下降。探究雌鼠胎间隔与雄鼠交配间隔时间对KM小鼠繁殖性能的影响,为KM小鼠繁殖生产和选种、育种提供参考。选择不同胎间隔的雌性及不同交配间隔的雄性KM小鼠,以雄鼠∶雌鼠=1∶2的比例同笼7d,在生产繁殖过程中统计雌性KM小鼠的繁殖性能相关指标,包括妊娠率、产仔数、初生仔鼠平均体重、离乳数及初生仔鼠窝重,并进行统计学分析。结果显示,胎间隔时间超过102d的雌性与交配间隔大于60d的雄性小鼠合笼后的妊娠率、离乳数和初生仔鼠窝重相比于没有时间间隔雌雄鼠均有显著性下降(P0.05,P0.01);胎间隔时间超过102d的雌鼠或交配间隔大于60d的雄鼠,在与对应的无间隔的雄鼠、雌鼠合笼后,妊娠率、离乳数和初产生仔鼠窝重等繁殖性能指标亦有显著性下降(P0.05,P0.01)。研究表明,雌鼠胎间隔时间超过102d和雄鼠交配间隔时间超过60d,均显著降低KM小鼠的繁殖性能。     

旱养对种鸭行为的影响观察

为研究旱养对种鸭行为的影响,选择健康、体重相近的1 200只樱桃谷肉种鸭(母鸭1 000只、公鸭200只),随机分为对照组(水养组)和试验组(旱养组),每组3个重复,每个重复200只。每天6∶00~7∶00对采食行为进行观测,7∶00~8∶00对采食以外的其他行为进行观测。结果:试验组种鸭采食、饮水频次显著低于对照组(P0.05);休息、行走以及攻击行为频次试验组均显著高于对照组(P0.05);站立、展翅、梳羽、抖尾等行为频次两组间无显著差异(P0.05)。在持续时间和时间比例上,休息、其他行为试验组显著高于对照组(P0.05);抖尾行为在持续时间上,试验组显著高于对照组(P0.05),但饮水、站立、行走、梳羽、展翅、攻击行为两组间无显著差异(P0.05)。试验表明,种鸭旱养可降低采食、饮水频次,提高种鸭的休息和抖尾的时间,但攻击行为频次增加,生产中要慎重选择种鸭旱养。     

动情期和动情间期雌性小鼠GR和TH的免疫活性及血清CORT水平的比较

受到卵巢雌激素和孕激素波动的影响,动情周期会影响雌性动物的行为和情绪。然而,关于引起这些行为改变的神经内分泌机制还需要进一步研究。通过阴道脱落细胞染色法确定小鼠动情周期的各个阶段。用酶联免疫吸附法检测动情期和动情间期血清雌二醇(E2)和皮质酮(CORT)水平,用免疫组织化学方法检测脑区糖皮质激素受体(GR)和酪氨酸羟化酶(TH)阳性神经元的表达。结果发现,与动情间期雌鼠相比,动情期雌鼠血清E2浓度升高(P0.05),但CORT水平没有变化;海马CA1区和齿状回(DG)GR-IR神经元表达增加(P0.05),下丘脑室旁核(PVN)和中脑腹侧被盖区(VTA)的TH-IR神经元表达增加(P0.05)。结果说明,雌性小鼠在动情期和动情间期GR和儿茶酚胺能神经元活动不同,这些差异可能是动情周期引起行为变化的一个重要因素。     

DHEA对小鼠肌肉中部分矿物元素含量的影响

为了观察脱氢表雄酮(DHEA)对小鼠肌肉中部分矿物元素含量的影响,选取昆明小鼠80只,随机分成4组,公母各半,各组小鼠DHEA日摄取量分别为0(对照组),20,40和60 mg/kg,测定肌肉中Fe、Mg、Zn、K、Ca的含量,试验期4周。结果表明:高剂量的DHEA能够降低小鼠胸肌中各元素的含量;DHEA能够提高雌鼠腿肌中5种元素的含量,但仅Fe、Mg、K达到显著水平(P<0.01,P<0.05),而雄鼠仅Fe、Mg含量显著升高(P<0.01,P<0.05)。高剂量组雄鼠腿肌中Fe、Ca含量显著高于雌鼠(P<0.05),Mg含量极显著低于雌鼠(P<0.01)。说明小鼠肌肉中5种矿物元素的含量受DHEA的调节。     

有机硒的急性毒性试验及对老龄小鼠抗疲劳、抗氧化功能的影响试验

为了解地肤子有机硒产品的急性毒性和对老龄小鼠抗疲劳及抗氧化功能的影响及其安全性,进行了急性毒性短期喂养试验,将28只10月龄以上小鼠根据雌雄不同随机分为6组,分别为雌鼠对照组、雌鼠低硒组(0.2%)、雌鼠高硒组(1%),雄鼠对照组、雄鼠低硒组(0.2%)和雄鼠高硒组(1%)。试验组小鼠自由采食对应的有机硒饲料,饲喂3周试验结束前用转棒疲劳仪测定了小鼠的抗疲劳能力;剖检小鼠,测定了脏器指数和主要脏器的抗氧化指标。结果表明:添加地肤子有机硒组小鼠没有出现急性毒性;通过短期喂养试验,发现地肤子有机硒对老龄小鼠有抗疲劳作用,并且对雌性小鼠的抗疲劳作用优于雄性,对雌雄小鼠肝脏、肾脏抗氧化指标都有良好的影响。     

成虫营养对桑螟雄蛾交配后内生殖器恢复的影响

明确不同营养状态下桑螟雄蛾交配后的生理状态,为利用性信息素监测和防控桑螟提供更多基础支撑。在桑螟取食葡萄糖、水以及饥饿处理下,分别对交配后不同时间的雄蛾进行解剖,比较不同营养状态下桑螟雄蛾内生殖器特征。取食葡萄糖的桑螟雄蛾,交配后0 h、6 h,内含物状态一致;交配后12 h, PS5段、复射精管、储精囊和附腺内含物逐渐恢复,PS5段内含物等级高于交配后0 h和6 h,但差异不显著;交配后24 h,整个生殖器恢复至交配前状态。取食水的桑螟雄蛾,交配后6 h、12 h的PS5段内含物等级均显著高于交配后0 h,交配后24 h,内含物等级为4级,含量显著高于交配后0 h、6 h、12 h;复射精管、储精囊和附腺内含物逐渐增加,交配后24 h恢复至未交配前的状态。饥饿状态的雄蛾,交配后6 h,复射精管、储精囊和附腺基部内含物即可恢复至交配前状态,PS5段内含物等级为4级,但管壁内并未完全被白色内含物填满;交配后12 h, PS5段完全被白色内含物填满,整个生殖器完全恢复至交配前的状态。根据雄蛾内生殖器不同部位内含物含量可鉴别12 h内桑螟雄蛾不同营养下的交配状态,结合精巢体积,有助于判断田间...     

环境浓度三丁基锡对根田鼠情感行为的影响

旨在研究环境浓度三丁基锡（tributyltin,TBT）对根田鼠情感行为的影响。实验组用1.0μg/m L的TBT按5μL/（g·BW）每3 d灌胃1次,对照组用等体积生理盐水做相同处理,暴露实验持续45 d。灌胃结束后,连续3 d对所有根田鼠进行旷场实验、高架十字迷宫实验和强迫游泳实验,观察根田鼠情感行为的变化。结果显示,在旷场实验中,雌、雄实验组根田鼠在四角格、中央格、过线频次上与对照组相比均无显著差异;雌性实验组根田鼠在四角格的直立频次显著高于对照组（P〈0.05）。在高架十字迷宫实验中,雌、雄实验组根田鼠在封闭臂内的时间和频次、开放臂频次及探头频次与对照组相比均无显著差异;而雌性实验组根田鼠在开放臂的时间显著低于对照组（P〈0.05）,探头时间显著高于对照组（P〈0.05）,雄性实验组根田鼠在开放臂的时间显著低于对照组（P〈0.05）。在强迫游泳实验中,雌、雄实验组根田鼠在静止潜伏期、静止时间和频次上与对照组相比均无显著差异。研究证实,该剂量的TBT会导致根田鼠出现轻度焦虑,尤其是雌性根田鼠,但环境浓度的TBT不会导致根田鼠抑郁。     

树食物识别的视觉刺激和化学刺激试验

为了探索树食物识别的机制,试验采用4种处理方法:(A)空白对照,(B)黄粉虫气味,(C)密封的黄粉虫,(D)黄粉虫,每个个体每种处理均进行6次试验。结果表明:不同处理条件下的探究频次、啃咬频次、行为持续时间差异显著(P0.05)。树在处理C(视觉刺激)及处理D(既有化学刺激又有视觉刺激)条件下的行为持续时间、探究频次和攻击频次显著高于处理B(化学刺激)(P0.05)。在无视觉刺激的条件下,树在处理B的行为持续时间、探究频次、啃咬频次显著高于处理A(P0.05)。在视觉刺激相同的条件下,树在处理D的行为持续时间显著长于处理C(P0.05)。树主要利用视觉捕食,化学识别为辅。     

水解蜂蛹蛋白对大鼠免疫功能的影响

为了研究水解蜂蛹蛋白对大鼠免疫功能的影响及性别之间的差异,选用50只3周龄SD大鼠随机分成2组,分别灌胃蜂蛹蛋白粉和经消化酶水解的蜂蛹蛋白4周.结果表明,饲喂水解蜂蛹蛋白雌鼠胸腺指数比对照组提高30.00%(p＜0.05),雄鼠脾脏指数比对照组提高8.33%(p＜0.05),而雌鼠脾脏指数和雄鼠胸腺指数与对照组无显著差异.饲喂水解蜂蛹蛋白组雌鼠和雄鼠血清IgG的含量分别比对照组增加21.82%(p＜0.05)和41.34%(P＜0.05);雌鼠血清IgA含量比对照组增加52.78%(0＜0.01).结果提示,水解蜂蛹蛋白有增强大鼠的免疫功能的作用,且存在一定的性别差异.     

血清学检测的雄性特异性抗原Fab抗体的特异性鉴定

旨在研究血清学检测的雄性特异性抗原噬菌体Fab抗体的特异性。以从噬菌体Fab抗体库中筛选到具有较高雄性特异性结合活性的重组噬菌体克隆为基础,构建Fab抗体的可溶性表达噬质粒,并诱导和纯化该抗体片段,利用免疫荧光FITC/DAPI共染技术和ELISA分析其特异性。结果表明,该抗体在约49 ku处有条带出现。在Fab抗体和H-Y抗血清的细胞免疫荧光比较分析试验中发现,从雌、雄鼠脾细胞的阳性细胞数量和平均荧光强度的角度分析,Fab抗体的雄性特异性强于抗血清。石蜡切片免疫荧光定量分析显示,Fab抗体与雄鼠肝脏的结合活性明显高于对应雌鼠,差异极显著(t=20.73,P=0.002 3<0.01),而H-Y抗血清与雄鼠肝脏的结合活性略高于对应雌鼠,差异显著(t=7.11,P=0.019 2<0.05)。以C57BL/6雄鼠脾细胞、睾丸细胞作为抗原的ELISA分析显示,Fab抗体具有雄性特异性,但Fab抗体的OD值低于抗血清。结果提示,Fab抗体的雄性特异性高于H-Y抗血清,但其雄性特异性结合活性低于H-Y抗血清,Fab抗体在具备雄性特异性的同时,仍有少量雌性非特异性结合,Fab抗体的体外亲和力成熟可作为后续研究工作,以获...     

Sex differences in the influence of social context,salient social stimulation and amphetamine on ultrasonic vocalizations in prairie voles

Prairie voles (Microtus ochrogaster) are a socially monogamous rodent species and their cooperative behaviors require extensive communication between conspecifics. Rodents use ultrasonic vocalizations (USVs) to communicate and because a prairie vole breeder pair must engage in extensive cooperation for successful reproduction, auditory communication may be critical for this species. Therefore, we sought to characterize USVs in adult male and female prairie voles, and to determine how these calls are influenced by social context, salient social stimuli and the psychostimulant drug of abuse amphetamine (AMPH). Here, we characterize prairie vole USVs by showing the range of frequencies of prairie vole USVs, the proportion of various call types, how these call types compare between males and females, and how they are influenced by social stimulation and AMPH. AMPH caused a robust increase in the number of USVs in both males and females and there was a dramatic sex difference in the complexity of call structures of AMPH‐induced USVs, with males emitting more elaborate calls. Moreover, we show that novel (i.e. salient) social cues evoked differential increases in USVs across sex, with males showing a much more robust increase in USV production, both with respect to the frequency and complexity of USV production. Exposure to an estrous female in particular caused an extraordinary increase in USVs in male subjects. These data suggest that USVs may be a useful measure of social motivation in this species, including how social behaviors can be impacted by drugs of abuse.     

贝奥不育剂和溴敌隆抗凝血杀鼠剂对布氏田鼠种群控制作用的试验研究

2013年5-9月,在内蒙古锡林郭勒盟东乌珠穆沁旗草地研究贝奥不育剂、溴敌隆灭鼠剂对草原主要害鼠布氏田鼠的控制作用。通过早春一次性足量投饵(贝奥不育剂野外有效期30~60 d;溴敌隆灭鼠剂野外有效期30 d),按月铗捕调查的方法研究贝奥不育剂和溴敌隆杀鼠剂对该地布氏田鼠种群增长的控制效果。结果表明,5月不育剂组布氏田鼠的家系大小较杀鼠剂组的家系更大且差异显著(P<0.05),6月差异不显著,杀鼠剂组布氏田鼠种群恢复速度比不育剂组快。贝奥不育剂改变了布氏田鼠种群的性比,其幼体出生率比杀鼠剂组低。因此,贝奥不育剂对布氏田鼠有更好的防治效果。     

不同不育比例对布氏田鼠种群增长的影响

在围栏条件下采用重捕法跟踪了不同比例不育个体对种群的影响.结果表明:正常繁殖组(对照)6-8月份均有新生小鼠,9月份以后停止繁殖.其中6月份雌鼠繁殖率为 5 %,7月份雌鼠繁殖率为0%,8月份雌鼠繁殖率为33%.繁殖期后,种群数量下降.在当年数量波动呈单峰型曲线.而各不育比例的试验组则均呈下降趋势;无论雄性或雌性的完全不育组的种群均在3-个月的时间内全部灭绝.说明在没有新生幼鼠的加入种群更替的情况下,由越冬鼠组成的种群将很快消亡;部分不育组的繁殖率均低于对照组.其中1/3雄性不育组及1/3雌性不育组的繁殖率均高于2/3雄性不育组及2/3雌性不育组,这种现象意味着该鼠的婚配制度并非混交制.在试验期间所有部分不育的种群均呈负增长;部分不育组中,当年出生的鼠没有参加繁殖.可能是不育个体干扰了其交配.因此,使用不育剂可能成为控制布氏田鼠种群数量的有效对策.     

Diet shift in bank voles induced by competition from grey‐sided voles?

Grey‐sided voles (Myodes rufocanus) and bank voles (Myodes glareolus) co‐exist in boreal forests in northern Scandinavia. Previous studies suggest that the 2 species interact interspecifically, the grey‐sided vole being the dominant species. We tested the hypothesis that bank voles shift their diet due to competition with the dominant grey‐sided vole by studying stable isotope ratios in both species. Muscle samples were taken from voles in patches of old forest occupied by only bank voles and patches of old forest occupied by both grey‐sided voles and bank voles. We found that: (i) stable isotope ratios of bank voles differed in areas with and without grey‐sided voles; and that (ii) the stable isotope ratios of bank voles were more similar to those of grey‐sided voles in areas where grey‐sided voles were absent. Our data suggests that grey‐sided voles forced bank voles to change their diet due to interspecific competition.     

Vole preference of bilberry along gradients of simulated moose density and site productivity

Browsing by large herbivores might either increase or decrease preference for the plant by other herbivores, depending on the plant response. Using a cafeteria test, we studied the preference by root voles (Microtus oeconomus [Pallas, 1776]) for bilberry (Vaccinium myrtillus L.) previously subjected to 4 levels of simulated moose (Alces alces [Linnaeus, 1758]) density. The different levels of moose density were simulated at population densities relevant for Fennoscandian conditions, in exclosures situated along a site productivity gradient. We expected: (i) voles to prefer bilberry from high productivity sites over low productivity sites; (ii) voles to prefer browsed bilberry, if plants allocate resources to compensatory growth or to avoid browsed bilberry if plants allocate resources to defense; (iii) these effects to increase with increasing simulated moose density; and (iv) the concentration of plant chemicals and the plant morphology to explain vole preference. Specifically, we predicted that voles would prefer: (i) plants with high nitrogen content; (ii) plants with low content of defensive substances; and (iii) tall plants with long shoots. Voles preferred bilberry from the high productivity sites compared to the low productivity sites. We also found an interaction between site productivity and simulated moose density, where voles preferred unbrowsed plants at low productivity sites and intermediate levels of browsing at high productivity sites. There was no effect of plant chemistry or morphology on vole preference. We conclude that moose browsing impacts the food preference of voles. With the current high densities of moose in Fennoscandia, this could potentially influence vole food selection and population dynamics over large geographical areas.     

模拟条件下布氏田鼠对草原植被的作用1——植被生物量的影响

2007年5-10月在模拟条件下研究了不同密度的布氏田鼠Lasiopodomys brandtii啃食对草原植被生物量、植物补偿生长量的影响。结果表明:1）植被生物量与布氏田鼠密度关系呈现了“低-高-低”的变化趋势;鼠密度每100 m2<5只时,植被生物量呈增加趋势。鼠密度每100 m2为5只时,其植被生物量增长达到最高值,随鼠密度的增加,植被生物量下降。2）植物补偿生长量与布氏田鼠密度相关呈单峰型曲线,鼠密度每100 m2为8只时植被的补偿生长量最高。3）植被生长可承受的鼠密度每100 m2 为4只(折合400只/hm2),鼠密度每100 m2≤4只时刺激植物生长,且可稳定植被群落结构。     

Bulls fail to show preference for estrous females in serving capacity tests

Eighteen sexually experienced Hereford bulls were exposed individually to a pair of restrained hormone-induced estrous and nonestrous females to determine mating preferences in the context of serving capacity testing. No evidence was obtained to support the hypothesis that restrained estrous females are more attractive to bulls than restrained nonestrous females. Estrous and nonestrous females received similar numbers of mount intentions, mount attempts, mounts without ejaculations and ejaculations during the 20-min tests. Time spent with estrous and nonestrous females and latencies to leave initially chosen estrous and nonestrous females to investigate the alternative female also were similar. Bulls interacted more with the females that they contacted first, regardless of estrous condition. A female position effect was noted. We conclude that restrained nonestrous females are as effective as restrained estrous females in assessing the serving capacity of Hereford bulls.     

Mating management.

The mating management of pigs is conducted under a wide spectrum of management techniques because females are variously hand-mated, pen-mated, or artificially inseminated. Factors that may affect the onset of estrus when hand-mating are boar exposure, method of housing females after weaning, season, type of facilities, and parity. The expression of sexual behavior in both male and female pigs can be influenced by a variety of physiologic, psychological, and environmental factors. To optimize the efficiency of estrous detection, females should not receive boar stimuli just prior to estrous detection when either hand-mated or artificially inseminated. When females are pen-mated, management procedures need to be employed to prevent an excessive number of estrous females from accumulating, which leads to a decrease in boar fertility.