Exogenous eFSH, follicle coasting, and hCG as a novel superovulation regimen in mares

The objective of this study was to evaluate various equine follicle-stimulating hormone (eFSH) treatment protocols and the effect of “follicle coasting” on ovulation and embryo recovery rates in mares. Cycling mares (n = 40) were randomly assigned to one of four groups 7 days after ovulation: (1) 12.5 mg eFSH twice daily until follicles were 35 mm or larger; (2) 12.5 mg eFSH twice daily until follicles were 32 mm or larger; (3) 12.5 mg eFSH twice daily for 3.5 days followed by 12.5 mg eFSH enriched with luteinizing hormone (LH) twice daily until follicles were 35 mm or larger; and (4) 25 mg eFSH once daily until follicles were 32 mm or larger. Mares in groups 1 and 3 were injected with human chorionic gonadotropin (hCG) (2500 IU intravenously) at the end of eFSH treatment, whereas mares in groups 2 and 4 were given hCG approximately 42 and 54 hours, respectively, after the last eFSH treatment (“follicle coasting”). Nonsurgical embryo collection was performed 6.5 to 7.5 days after ovulation. Each mare experienced a nontreated estrous cycle before being reassigned to a second treatment. Ovulation rates for mares in treatment groups 1 to 4 were 3.3 ± 0.4, 4.1 ± 0.4, 3.5 ± 0.4, and 2.8 ± 0.4 (mean ± SEM; P < .05), respectively. One or more embryos were recovered from more than 80% of mares in each treatment group, and embryo recovery rate per flush was similar among treatment groups (1.9 ± 0.3, 2.6 ± 0.3, 1.9 ± 0.3 and 1.9 ± 0.3, respectively; P > .05). The overall embryo recovery rate was 2.1 ± 1.5 embryos per flush. In summary, ovulation rate was higher for mares treated with eFSH (3.4 ± 0.4) compared with non-treated controls (1.1 ± 0.2). Ovulation rate in mares in which hCG was delayed (follicle coasting) was higher (P < .05) when treatments were given twice per day versus once per day. Administration of equine luteinizing hormone (eLH) in conjunction with eFSH did not have an advantage over mares treated only with eFSH.     

猪流感病毒A/swine/Guangdong/2/2012(H1N1)毒株攻毒BALB/c小鼠细胞因子动态变化的研究

为了测定H1N1亚型猪流感病毒(swine influenza virus,SIV)对小鼠的致病性,本试验对A/swine/Guangdong/2/2012(H1N1)株SIV HA基因进行克隆及遗传分析,并将SIV尿囊液经鼻腔感染6周龄BALB/c小鼠,观察感染后小鼠的一般状况、器官系数和组织病理学变化,在病毒感染后第1、3和7天使用荧光定量PCR测定小鼠肺脏、脾脏、脑组织中7种细胞因子mRNA的表达量,研究其对小鼠的致病特性。结果显示,该病毒属于经典SIV,病毒经鼻腔感染后可引起小鼠活动减少、采食量降低,但无咳嗽和死亡;病理组织学变化为肺间隔较正常组织明显增厚,毛细血管明显扩张充血,周围肺泡腔呈代偿性肺气肿;小鼠肺脏、脾脏组织样本中IFN-α、IFN-β、IP-10、IL-1β、TNF-α、IRF-3和IL-10 mRNA含量在感染后第3天均显著升高(P<0.05),而脑组织样本中IL-1β和IL-10在小鼠攻毒后第3和7天均显著上调(P<0.05)。     

甘肃陇南地震扰动区植被群落特征

地震扰动对当地生态环境造成极大的破坏,引起植被群落种类组成、群落结构的变化,本研究采用样带结合海拔梯度的方法,于2013年8-9月,调查和研究了甘肃陇南武都区清水沟植被群落的种类组成、群落结构受地震扰动后的现状。结果表明,研究区内共发现34种植物,分属16科30属,主要以禾本科和菊科植物为主,群落垂直结构明显,大体分为3层;植物群落中多年生草本植物种类最多,是优势生活型,其次是灌木、藤本,无乔木分布;Shannon-Wiener多样性指数(H')和Pielou均匀度指数(E)表现为中坡位>下坡位>上坡位,Simpson优势度指数(D)表现为上坡位>下坡位>中坡位。     

草粮轮作与农田生态平衡——兼论 Ladino 白三叶的生态经济效益

利用无性繁殖法定植Ｌａｄｉｎｏ白三叶（Ｔｒｉｆｏｉｕｍｒｅｐｅｎｓ）和雅安逸生白三叶（Ｔ．ｒｅｐｅｎｓ），地上部生物量前者比后者表现出极显著差异；地下部生物量和贮氮量表现为显著差异。后作玉米产量，Ｌａｄｉｎｏ白三叶地为６．２９ｔ／ｈａ大于雅安逸生白三叶地（６．１５ｔ／ｈａ）；农田生态系统里前者表现为正氮平衡，后者表现为负氮平衡，前者土壤固相、液相和气相比为１∶０．５∶０．２５明显优于后者；前者Ｃ／Ｎ比适中，后者Ｃ／Ｎ过窄，其抗性雅安逸生白三叶低于Ｌａｄｉｎｏ白三叶。三种种子直播的豆科牧草的生态经济特性表现为南苜蓿（Ｍｅｄｉｃａｇｏｈｉｓｐｅｄａ）大于苕子（Ｖｉｃｉａｃｏｒａｃｃａ），紫云英（Ａｓｔｒａｇａｌｕｓｓｉｎｉｃｕｓ）则介于两者之间。草粮轮作周期证明，Ｌａｄｉｎｏ白三叶和南苜蓿以及苕子是无性繁殖和有性繁殖的最佳材料，值得广泛推广利用。     

Competing seed consumers drive the evolution of scatter-hoarding: Why rodents do not put all their seeds in one larder

Competition for food resources amongst animal seed dispersers and pilferers has driven dispersers to increasingly innovative seed-caching methods.We determined cache sizes in the field as well as seed cache recovery ability of a scatter-hoarding mouse, Acomys subspinosus, and compared these results to its seed competitor, the seed predator Rhabdomys pumilio.We found that up to 76% of A. subspinosus caches in the field contained one seed and that A. subspinosus was able to find caches of all sizes equally well under wet and dry soil conditions. In contrast, R. pumilio was able to find caches of all sizes in wet soil conditions but recovery success of small caches (single-seed) was poor in dry soil conditions. This suggests that scatter-hoarding may have evolved in A. subspinosus as an anti-pilfering strategy. This strategy would likely work best in dry conditions, where cache pilferers have difficulty locating small caches.     

内蒙古白绒山羊附睾精子冷冻效果的研究

本试验把不同温度下的样品分成3个处理组,通过检测精子与繁殖力有关的重要指标研究3个处理组的冷冻效果,结果显示, 在3个不同的环境下收集附睾,室温下(19 ℃)收集附睾精子(处理1组)的冷冻效果最好,解冻后活率为(55.0±3.4)%;4 ℃下收集的精子(处理2组)冷冻解冻后的活率为(35.0±2.5)%;37 ℃下收集的精子(处理3组)的冷冻效果较差,解冻后活率为(23.0±2.5)%。通过对处理组中冷冻和解冻后两个阶段的精子指标的测定,研究了精子活率与其他指标的关系,得出白绒山羊附睾精子能够成功的保存。     

氮磷钾配施对甘草育苗质量的影响

利用“3414”方案进行N、P、K营养液配方设计,在配方营养液浇灌条件下进行甘草育苗质量比较,旨在探寻适宜甘草育苗的施肥配方,为其测土配方施肥和无土栽培育苗提供依据。结果表明,以纯沙石作为育苗基质,在添加Hoagland营养液条件下,不同N、P、K配比营养液对经98%硫酸处理的甘草种子的出苗质量和幼苗生长发育均具有极显著影响。N₂K₂配比下出苗质量均优于空白对照,且随着施磷水平的提高出苗质量呈下降趋势,出苗质量依次为N₂P₀K₂＞N₂P₁K₂＞N₂P₂K₂＞N₂P₃K₂。而出苗活力依次为N₂P₁K₂＞N₂P₀K₂＞N₂P₂K₂＞N₂P₃K₂。N₂P₂K₂和N₂P₁K₂处理均可极显著提高甘草根系活力,为培育壮苗奠定良好基础。单纯缺N、缺K和过量N、P和K肥均不利于甘草出苗和幼苗的生长发育。以上说明在甘草出苗阶段需P量小,但出苗后开始显示其营养效应。从育苗效益和环境保护双重考虑,配方施肥宜采用N₂P₁K₂,即添加80 mg/L NH₄NO₃、89 mg/L KH₂PO₄和298 mg/L KNO₃作为N、P和K营养源,每隔20 d浇1次。需要注意的是浇灌后应及时喷灌适量水,使氨态氮下渗到底部基质,以避免氨的挥发而灼伤幼苗。     

桉树无性系的单板出材率与价值研究

为了系统深入地对单板出材率和价值的影响因素进行研究,以11个6年生桉树无性系为材料,使用无损检测仪器Pilodyn和Fakopp测定立木的外部密度和应力波传输速度,用轴向生长应变仪器CIRAD-ForestMethod测定立木生长应力,结合对原木外观形质的检测和单板质量等级的划分,运用差异性分析、相关分析及多元逐步回归分析。结果表明,无性系间立木的材性性状,原木形质中的小头最小直径、弯曲度和端裂指数存在显著差异。节疤,尤其死节(孔洞)、裂缝是降低单板等级的主要因素。无性系间单板出材率和价值存在显著差异,其中出材率(%)从大到小排序为:GL₉(48.27),EC₃₄(47.17),LH₁(44.00),DH_32-22(42.00),GL₄(37.56),SH₇(34.88),UC_184-1(34.38),LH₅(31.06),M₁(29.74),DH_201-2(25.41),SG₁(16.28),最大是最小的2.97倍;单段原木价值(RMB/log)从高到低排序为:EC₃₄(13.37),GL₉(13.12),GL₄(12.36),LH₁(12.02),DH_32-22(11.55),LH₅(10.72),SH₇(9.22),UC_184-1(7.95),M₁(7.55),DH_201-2(5.97),SG₁(4.88),最高是最低的2.74倍;单位材积价值(RMB/m³)从高到低排序为:EC₃₄(856.49),LH₁(794.55),GL₉(788.68),DH_32-22(763.02),GL₄(681.44),SH₇(629.35),UC_184-1(597.66),LH₅(559.08),M₁(538.39),DH_201-2(450.49),SG₁(294.53),最高是最低的2.91倍。5个品种的无性系作为胶合板用材,尾巨桉无性系价值最高。原木弯曲度是影响单板出材率和价值的主要因素,木材密度、小头直径、应力波传输速度及端裂指数等对其也有显著影响。无损检测仪器Pilodyn和Fakopp可对单板出材率和单位材积价值进行粗略预测。     

施氮对新灌区不同间套种植模式产量及茬口养分特性的影响

在甘肃秦王川新灌区的大田试验表明，春小麦//蚕豆、春小麦/油菜、春小麦/马铃薯及春小麦//草木樨等4种间套种植模式均能提高农田的生产力；豆料作物与牧草显著地改善耕层的茬口养分特性，草木樨茬口不但速效养分含量高于其他模式，对提高土壤有机质和降低土壤容重也有明显效果。施氮能显著提高各种植模式的综合经济产量，但过量施氮时增产效果又有所下降，且在各茬口的速效磷含量产生较弱的负效应。