养猪场消毒要领

一、消毒药品的选购原则1．消毒药品要具有杀灭病原体能力强、广谱高效、作用迅速；对人和动物无毒害作用；对金属制品、木制品、塑料制品、用具及衣物等无腐蚀作用；对环境及供水无污染作用等。     

植物化感作用的生态学意义及在草地生态系统中的研究进展

植物化感作用会在不同的研究尺度影响生态学过程,也被认为是生物入侵的重要作用机制,近年来成为生态学领域的研究热点。目前针对化感物质的分离、鉴定、释放途径及作用机理和化感作用的应用潜力等方面已开展了大量的研究工作,但对化感作用在不同时空尺度生态学过程中的具体作用和贡献及在草地生态系统中的研究进展还缺乏深入系统地概述,限制了对化感作用生态学意义的准确理解。笔者综述了近年来化感作用在不同尺度生态学过程特别是草地生态系统中的研究进展,从化感作用与种间竞争的区分与联系、化感作用对群落物种组成、群落演替及生物入侵等生态学过程的影响入手阐述了植物化感作用的生态学意义,总结了草地生态系统中化感作用的研究现状。基于当前植物化感作用研究存在的问题和争议,提出未来的研究应重点关注化感作用的室内观测结果与野外群落或生态系统水平观测结果的对比分析、区域乃至全球尺度的化感作用研究及化感作用在草本植物防御过程中的作用机制等方面。     

抗菌肽的研究与应用

抗菌肽是生物体先天性免疫系统的重要组成部分,是一类具有光谱抗菌活性的小肽类物质。大量研究表明,除了抗菌作用外,抗菌肽还有抗真菌、病毒及癌细胞的作用。本文对抗菌肽的来源、分类、结构、特点及作用机理等方面进行了总结,并阐述了目前抗菌肽的研究及应用。     

烟酸对奶牛代谢和生产性能的影响

本文综述了烟酸的特点、营养作用机理;烟酸在奶牛体内代谢作用及对瘤胃微生物和瘤胃发酵的影响;烟酸对奶牛产奶性能、预防酮病的作用及奶牛生产中烟酸的需要量等多方面的研究。     

蛋氨酸锌对奶牛营养作用效果与机理的研究进展

本文就有机锌对奶牛的营养作用效果、影响有机锌作用效果的因素及有机锌作用机理研究进展进行综述。     

列当多糖对鸡新城疫病毒在鸡成纤维细胞中增殖的抑制作用

为研究列当多糖抗新城疫病毒(NDV)活性,用水提醇沉法提取列当总多糖及4种分级多糖,并通过苯酚硫酸法及红外光谱对列当多糖进行检测。通过MTT法测定各级多糖对鸡胚成纤维细胞(CEF)的安全浓度。以3种加药方式(先加多糖后接种病毒、先接种病毒后加多糖、多糖和病毒感作后加)加药,检测列当多糖对新城疫病毒的阻断作用、抑制作用及直接杀灭作用。结果表明,列当总多糖及4种分级多糖均具有抗NDV活性,其中对NDV的抑制作用及阻断作用强于对NDV的直接杀灭作用。50%、80%梯度醇沉的列当多糖(OSP50、OSP80)及总多糖(OSPt),阻断作用下的病毒抑制率分别为19.50%、33.10%和22.30%,抑制作用下的病毒抑制率分别为19.00%、21.90%和22.60%,杀灭作用下对NDV的抑制率分别为,14.70%、17.50%和13.30%,其余各组多糖阻断作用、抑制作用及杀灭作用下的病毒抑制率均低于上述3组多糖。说明OSP50、OSP80及OSPt的抗NDV活性较好,可以作为进一步研究的材料。     

电压互感器结构原理及常见故障介绍

电压互感器在电力系统运行中起着重要作用,无论是互感器本身还是二次回路出现问题,都将给整个二次系统带来严重影响。所以,本文对电压互感器的原理及作用、型号、接线方式、变比选择及常见故障及现场处置方案做了简单的阐述及总结。     

硒对重金属毒性的颉颃作用

硒是动物机体必需的微量元素,是谷胱甘肽过氧化物酶的组成成分,这种酶的作用是抑制过氧化反应、清除自由基、分解过氧化物及修复分子的损伤,从而保护细胞膜的结构及功能不受过氧化物的干扰及损害。它还具有颉颃多种重金属元素毒性的作用。对目前产生污染较严重的几种重金属的危害及硒对重金属毒性的颉颃作用进行了论述。     

共轭亚油酸(CLA)对动物营养效应研究进展

本文对共轭亚油酸对动物的免疫作用、抗癌及防止动脉粥样硬化作用、抗氧化作用等进行了综述 ,重点论述了共轭亚油酸的营养再分配作用 ,并对有待继续研究的问题进行了探讨。     

营养对基因表达的影响

营养是基因表达的重要调节物。营养对基因表达的调控作用及其机制已成为分子生物学的重要研究内容及营养学的新兴研究领域。本文在介绍基因表达过程及营养调控途径的基础上 ,综述了能量与蛋白质、氨基酸、碳水化合物、脂肪与脂肪酸、矿物元素及维生素对相关基因表达的调控作用及主要机制     

茶多酚和有效微生物对育成期水貂粪便污染物排放量的影响

为研究饲粮中添加茶多酚(TP)和有效微生物(EM)对育成期水貂粪便污染物排放量的影响,试验选取400只育成前期水貂共160笼,随机分成8组,每组20个重复。采用两因素试验设计,共8个处理组,基础饲粮中分别添加0 EM+0 TP、0 EM+0.05%TP、0 EM+0.1%TP、0 EM+0.2%TP、200 mg/kg EM+0 TP、200 mg/kg EM+0.05%TP、200 mg/kg EM+0.1%TP、200 mg/kg EM+0.2%TP。预试期1周,正试期8周(前4周为试验I期,后4周为试验Ⅱ期)。结果表明:饲粮添加TP不能减少水貂粪便NH3、H2S和CO2生成量;饲粮添加200 mg/kg EM对水貂粪便NH3(48 h)、H2S(72 h和96 h)生成量有显著影响(P0.05);饲粮添加0.1%及0.2%TP可显著降低试验Ⅱ期粪便中氨氮含量(P0.05),饲粮添加200 mg/kg EM可降低粪便中总氮(试验I期)、总磷(试验I和Ⅱ期)、氨氮和亚硝酸盐氮(试验Ⅱ期)含量(P0.05)。由此可见,饲粮添加EM可以减少水貂粪便恶臭气体生成以及粪便污染物的含量,建议水貂饲粮中添加200 mg/kg EM。     

EM在肉牛养殖上的研究应用进展

EM(有效微生物)是含有多种有益微生物的复合制荆,在促进畜禽生长、提高畜禽抗病力、减轻粪尿恶臭以及改善生态环境方面均具有重要作用.作者对EM制剂的组成研制、使用方式、作用机理、在肉牛养殖上的应用及影响EM作用效果的因素等进行了综合阐述.认为应积极推广应用EM制剂,以促进养牛业健康持续发展.     

EM在长毛对虾养殖中的应用研究

ＥＭ有明显的促生长和改善水质的作用，在对是养殖的早期以２ｐｐｍ为佳，后期以４－６ｐｐｍ为宜。各种的综合分析表明：ＥＭ加充氧和ＥＭ混合在饵料中联合使用，可显著地提高对虾的生长和成活率。     

Comparison of a commercial enzyme-linked immunosorbent assay with electron microscopy, fluorescent antibody, and virus isolation for the detection of bovine and porcine rotavirus

The purpose in this study was to compare the sensitivity of a commercial enzyme-linked immunosorbent assay (ELISA) with electron microscopy (EM), fluorescent antibody (FA), and virus isolation (VI) for the detection of bovine and porcine rotavirus (RV). Seventy-three bovine and 116 porcine accessions were evaluated by 1 or all 4 diagnostic tests, where suitable specimens were available. For the bovine samples, agreement was 33% between FA and EM, 33% between FA and ELISA, and 92% between EM and ELISA. For the porcine samples, agreement was 79% between EM and FA, 72% between EM and ELISA, and 82% between ELISA and FA. Virus was isolated from 68% and 41% of the bovine and porcine fecal samples, respectively. Commercial ELISA was as sensitive as EM, but was more sensitive than FA or VI for the detection of RV in bovine feces. Electron microscopy was more sensitive than FA, ELISA, or VI for detection of RV in porcine feces. The ELISA was an advantageous alternative to the conventional methods of EM, FA, and VI for the diagnosis of RV in calf feces, but not for porcine feces.     

有效微生物群对仔猪生产性能的影响初探

对产后母猪和断奶仔猪饲喂有效微生物菌群(EM),研究其对仔猪生产性能的影响。从产前7d开始给母猪基础饲料中添加5mL/kg的EM菌液,选产仔数不少于8头的3头母猪及其仔猪连续饲喂EM菌28d,仔猪进行断奶,统计母猪的增重、仔猪初生重、断奶重,仔猪成活率等,分析添加EM菌后对母猪生产性能的影响。在这24头断奶仔猪饲料中添加EM菌的饲料,饲喂至60日龄,统计仔猪的增重、采食量、料重比、发病数等,分析EM菌断奶仔猪生产性能的影响。另外选取3头同品种、同批次生产、产仔数相同的母猪及其仔猪饲料中不添加EM菌作为对照。结果表明,母猪产后日均采食量较对照组提高12.07%,仔猪的初生重较对照组提高15.90%,产活仔数提高了12.09%,断奶重增加9.09%,断奶头数增多20.99%,断奶成活率提高8.81%。断奶后仔猪试验组的平均采食量较对照组提高10.26%,料重比降低了7.14%,发病率下降了50.03%。说明EM菌对母猪和仔猪的生产性能均有提高作用,研究结果为EM菌在生猪养殖中的应用提供了基础资料。     

EM微生态制剂对仔猪的保健效果观察

试验开展EM微生态制剂对仔猪增重效果、仔猪腹泻的控制效果、环境除臭及蚊蝇孽生繁殖的消除效果等研究,结果表明:(1)EM制剂对仔猪具有良好的育肥增重效果。试验组平均增重比对照组多1.981 kg,差异显著(P<0.05);(2)EM的添加对仔猪腹泻具有良好的控制效果。试验组死亡率为5%,治愈率为75%;对照组死亡率为40%,自愈率为30%;(3)EM微生态制剂能抑制腐败菌的生长繁殖,有明显消除粪便臭味,减少蚊蝇孽生繁殖,从而净化环境,减少污染,改善仔猪生长环境。结论:EM微生态制剂对仔猪具有保健效果。     

EM制剂对牛粪中氨气释放及微生物含量的影响

试验旨在探讨微生态制剂EM对牛粪中氨气释放及微生物含量的影响。试验设0（对照组）、0．5％、1％和2％四个EM添加水平,将200g牛粪与不同比例EM制剂混匀后置于盖有胶塞的三角瓶中恒温培养5d,测定培养过程牛粪中氨气产生量及培养结束后培养体系中氨氮、全氮和常见微生物含量。结果表明,各处理组均未检测到氨气的产生;EM处理组氨氮含量明显降低,且全氮含量明显升高,其中2％EM处理组与对照组及0．5％EM处理组差异显著（P〈0．05）;此外,2％EM处理组大肠杆菌含量显著低于对照组（P〈0．05）,乳酸茵含量则显著高于对照组和0．5％EM处理组（P〈0．05）。试验显示,EM制剂能降低牛粪中氨氮浓度及氮损失,调节微生态环境,从而减少氨的释放,改善畜舍空气质量。     

Repeatability and Heritability of Ovulation Number and Embryos in Dam-daughters Pairs in Superovulated Holstein–Friesian Cows

Holstein-Friesian dams (n = 28) and daughters (n = 28) were superovulated (total number of observations was 235) to determine the repeatability and heritability of ovulation number and embryo collection result for FSH treatment. The donor cows were superovulated with FSHp, artificial insemination was performed and embryo collection was carried out 7 days later. For the analysis, the raw corpdata of the number of corpora lutea (CL), the number of collected embryos (EM) and their log-transformed values were used (log CL, log EM). The genetic parameters were calculated by using the VCE4 software. For calculating heritability, the number of embryo collection was used as a random effect; for calculating repeatability, the permanent environment was fitted. The additive genetic variance of CL was 8.91 and that of the EM was 9.23. The additive genetic variance for the log CL and log EM were 0.457 and 0.340, respectively. The estimated heritability for CL and EM were 0.234 and 0.159, and repeatability were 0.386 and 0.301, respectively. Higher heritabilities but lower as the previous repeatabilities were observed for the log-transformed data, 0.266, 0.194 and 0.294, 0.208 for log CL and for log EM, respectively.     

Latex test for rapid rotavirus diagnosis in calves

A latex agglutination test (LA) was compared with direct electron microscopy (EM) for detection of rotavirus infection in calves. A total of 375 samples from 62 calves were collected. Samples were taken when the calves were 1, 3, 5, 7, 10 and 20 days old and some scours samples were collected as well. Altogether 45/375 (12%) specimens were positive in LA and 10/375 (2.7%) were positive in EM. Samples positive in EM were also positive in LA. Out of the 62 calves studied 26/62 (42%) were positive in LA and 8/62 (13%) in EM. We found the LA very easy to perform, to be more sensitive than the EM method and probably a rather specific method for detection of rotavirus infection.     

Employing a Monte Carlo algorithm in expectation maximization restricted maximum likelihood estimation of the linear mixed model

Multiple‐trait and random regression models have multiplied the number of equations needed for the estimation of variance components. To avoid inversion or decomposition of a large coefficient matrix, we propose estimation of variance components by Monte Carlo expectation maximization restricted maximum likelihood (MC EM REML) for multiple‐trait linear mixed models. Implementation is based on full‐model sampling for calculating the prediction error variances required for EM REML. Performance of the analytical and the MC EM REML algorithm was compared using a simulated and a field data set. For field data, results from both algorithms corresponded well even with one MC sample within an MC EM REML round. The magnitude of the standard errors of estimated prediction error variances depended on the formula used to calculate them and on the MC sample size within an MC EM REML round. Sampling variation in MC EM REML did not impair the convergence behaviour of the solutions compared with analytical EM REML analysis. A convergence criterion that takes into account the sampling variation was developed to monitor convergence for the MC EM REML algorithm. For the field data set, MC EM REML proved far superior to analytical EM REML both in computing time and in memory need.