鸭传染性浆膜炎疾病模型方法的建立

鸭传染性浆膜炎是鸭最常见的急性、败血性传染病之一,死亡率高,严重影响到养鸭业的发展。本试验通过对鸭传染性浆膜炎疾病模型的建立进行条件筛选,确立对6周龄雏鸭采用腹腔注射0.5 mL 4.5×10⁹ CFU/mL细菌浓度的鸭疫里默氏杆菌,5 h后鸭开始发病,3~5 d死亡率达80%,临床症状、病理学检查及病原学鉴定均符合该疾病模型复制的要求。本试验结果可以为该病的病理学研究及新药筛选提供理论依据。     

菊苣种子产量构成因子与产量的关联性分析

采用正交施肥试验设计与大样本取样,于2007年对菊苣(Cichorium intybus L.)种子产量及其构成因子进行研究,并通过相关分析、通径分析及回归分析,明确影响种子产量的主要因子和提高种子产量的主要因子,以期了解并掌握相应的关键技术。结果表明:菊苣的花序数、生殖枝数和种子产量主要受水肥条件控制;每株生殖枝数、每株花序数和千粒重是影响菊苣种子产量的主要因素,其回归模型为Y=-13.8887+1.73862X_{2+0.00241X3+21.7579X6;提高每株生殖枝数和每株花序数是菊苣种子高产的关键技术措施。}     

生长猪大米蛋白消化能、代谢能的评定及预测模型研究

本试验通过采集我国多个地区大米蛋白样品,分析大米蛋白常规成分,测定生长猪消化能(DE)、代谢能(ME),建立大米蛋白常规成分与生长猪DE、ME之间的关系。试验选用体重(33.0±1.3)kg的"杜×长×大"三元杂交健康去势公猪12头,采用2个6×6拉丁方试验设计,包括1种基础饲粮和11种大米蛋白替代15%基础饲粮的试验饲粮。采用全收粪法和套算法结合测定大米蛋白猪DE、ME,并将大米蛋白的常规成分与猪DE、ME进行相关和回归分析,建立大米蛋白猪DE、ME预测模型。结果表明,11种大米蛋白风干基础下猪DE为(18.13±1.12)M J/kg,M E为(16.44±1.59)M J/kg。由此得出,大米蛋白猪DE最佳预测模型(绝干基础)为DE=22.17-0.51NDF(R2=0.50,RSD=0.93),DE=18.58-0.49 CF+0.31 EE(R2=0.70,RSD=0.77);M E最佳预测模型(绝干基础)为ME=21.42-0.74 NDF(R2=0.52,RSD=1.30)。NDF为大米蛋白猪DE、M E最佳预测因子。     

A practitioner's guide to understanding equine infectious disease diagnostics in the United Kingdom. Part 1: How to optimise sampling approaches and a guide to agent detection testing methods

Diagnostic testing is routinely performed by the equine clinician when dealing with suspected infectious disease cases and outbreaks. Optimal sample timing, choice and handling are fundamental to attain an accurate diagnosis, and a good understanding of laboratory-based sample analysis techniques, and their validation is necessary for effective diagnostic test result interpretation. This two-part series highlights the importance of interpreting results bearing testing limitations and specific clinical findings in mind, and on these foundations, the treating clinician should always be well placed to deal with equine infectious diseases. Part 1 in this series will provide a treating clinician with an overview of the importance of testing horses in infectious disease outbreaks and how this is achieved. The different laboratory testing options available for agent detection and their methods will also be discussed. Part 2 will summarise serological (antibody) testing techniques, sample processing (including how tests are performed and validated) and result interpretation.     

基于NRC模型下不同玉米副产品代谢蛋白预测产量与分子功能团特征参数相关性分析

试验基于NRC-2001模型预测不同玉米副产品代谢蛋白产量,利用光谱技术分析不同玉米副产品的分子功能团特征及二者之间的相关性并建立回归方程。采用NRC-2001模型对奶牛饲料蛋白营养价值进行评价,利用傅立叶变换红外光谱（Fourier transform infrared,FTIR）技术收集光谱数据并分析。结果显示,利用NRC-2001模型预测不同玉米副产品代谢蛋白特征参数具有显著差异（P<0.05）。其中,小肠中真可吸收代谢蛋白总量在玉米蛋白粉中有最高值,其次是玉米胚芽饼、玉米胚芽、玉米皮及玉米籽粒。饲料产奶价值（FMV）存在相同趋势。在光谱结构分析中,饲料的分子功能团特征参数存在显著差异（P<0.05）,蛋白代谢预测产量与分子功能团特征参数之间存在相关性,建立的回归模型拟合度较好。其中,玉米籽粒中酰胺Ⅰ带与纤维性碳水化合物的面积比值（Amide Ⅰ_CELC）显著高于其他饲料原料（P<0.05）,玉米胚芽的酰胺Ⅰ带与结构性碳水化合物的面积比值（Amide Ⅰ_SCHO）和Amide Ⅰ_CELC比值均较低（P<0.05）,而玉米皮的蛋白质酰胺Ⅱ带与结构性碳水化合物（SCHO）和纤维性碳水化合物（CELC）之间的光谱面积比值均显著低于其他饲料比值（P<0.05）,玉米胚芽饼的蛋白质酰胺Ⅱ带与总碳水化合物之间峰面积比值（Amide Ⅱ_TNSCHO）显著高于其他饲料原料（P<0.05）。在不同玉米副产品饲料中,瘤胃合成微生物蛋白（MCP）和小肠真可吸收微生物蛋白（AMCP）含量与蛋白质酰胺Ⅰ带与非结构性碳水化合物之间的峰面积比值（Amide Ⅰ_TNSCHO）无显著相关性（P>0.05）,但与其他各光谱分子功能团特征参数存在显著负相关（P<0.05）。Amide Ⅰ_TCHO和Amide Ⅱ_SCHO可共同作为预测因子估测小肠真可吸收瘤胃非降解蛋白（ARUP）、代谢蛋白（MP）和FMV,其决定系数均为0.997。本试验结果表明,不同玉米副产品基于NRC-2001模型下代谢蛋白预测产量与分子功能团特征参数之间存在相关关系,可利用傅立叶变换红外光谱分析技术对饲料营养价值进行快速分析和估测。     

The Application and Research Progress of Chicken Embryo and Avian Cell Lines in Biomedicine

Chicken embryo has long been an important experimental model in basic and applied science because of its clear development process,especially in the early development of chicken embryo chorioallantoic membrane stage,due to its abundant blood vessels,it is a natural immunodeficiency host and can be used as an ideal experimental model for pathology,pharmacology and oncology research.The authors briefly described the tissue structure of early stage of chicken embryo,the application of chick embryo chorioallantoic membrane model in tumor,angiogenesis,organ transplantation,burn and other diseases,and the application of anti-cancer drug screening based on the pathological model of chicken embryo.The advances in the application of chicken embryo and avian cell lines in virus reproduction,vaccine production,therapeutic protein production and monoclonal antibody production were reviewed.A variety of human viruses,avian viruses and mycoplasma can proliferate in chicken embryos and avian cell lines and be used in vaccine production.In this paper,the development and characteristics of commonly used avian fibroblasts and pluripotent stem cells were described,and the source of commercial avian cell lines and some susceptible viruses were summarized.Chicken embryo expression system can produce human glycosylates at specific sites of target proteins,reduce the allergic reaction of the target protein to human,and poultry eggs are cheap and easily available,so it can be used as a suitable donor for the production of human monoclonal antibodies and therapeutic proteins.In this paper,the recent progress in the application of chicken embryos and avian cell lines in the field of biomedicine was introduced,and the future application of chicken embryos as animal models was forecasted.     

Genetic trends for fertility,udder health and protein yield in Swedish red cattle estimated with different models

The aim of this study was to estimate and compare genetic trends in Swedish Red cattle using a full multiple-trait (MT) model and trait-group-wise models for female fertility, udder health and protein yield. Field data for maiden heifers from 1989 and cows with a first and second lactation between 1990 and 2007 were included. (Co)variance components were estimated prior to prediction of breeding values. The estimated genetic trends were clearly favourable for protein yield and udder conformation, and in most cases neutral to favourable for clinical mastitis and calving to first insemination. In maiden heifers, the trends were neutral for number of inseminations per service period. Unfavourable genetic trends were estimated for number of inseminations in the first two lactations, but the trends seemed less unfavourable from evaluations within trait groups compared with when using the full MT model. Excluding maiden heifer data affected genetic trends less than using trait-group-wise analyses instead of a full MT model. Unfavourable genetic trends in functional traits may be missed unless the traits are evaluated in a MT model including traits under strong selection.     

奶牛场荧光定量PCR检测实验室建设实践与思考——以原生态牧业奶牛场实验室建设为例

荧光定量PCR技术用于病原微生物基因表达、基因组变异和多态性检测等,具有灵敏度高、特异性高、快捷、对样品要求低等优点,已广泛用于临床诊断和畜禽疫病诊断。本文以黑龙江原生态牧业奶牛场荧光定量PCR检测实验室建设为例,从设计规划、配套设备、人员配备、环境控制及存在问题解决五大方面进行论述,提出PCR实验室建设要根据奶牛场场地实际情况,规划适合PCR实验检测区域;根据PCR检测需求及奶牛场费用预算配置实验设备;根据奶牛场预计检测样品量配备检测人员及培养储备人员;在建立严格的操作规范基础上,严格执行实验分区管理及检测过程中消毒流程,避免实验过程中产生气溶胶污染环境。     

Assessment of stiffness and strength of 4 different implants available for equine fracture treatment: a study on a 20 degrees oblique long-bone fracture model using a bone substitute

OBJECTIVE: To compare the mechanical properties of 4 stabilization methods for equine long-bone fractures: dynamic compression plate (DCP), limited contact-DCPlate (LC-DCP), locking compression plate (LCP), and the clamp-rod internal fixator (CRIF--formerly VetFix). STUDY DESIGN: In vitro mechanical study. SAMPLE POPULATION: Bone substitute material (24 tubes) was cut at 20 degrees to the long axis of the tube to simulate an oblique mid-shaft fracture. METHODS: Tubes were divided into 4 groups (n=6) and double plated in an orthogonal configuration, with 1 screw of 1 implant being inserted in lag fashion through the "fracture". Thus, the groups were: (1) 2 DCP implants (4.5, broad, 10 holes); (2) 2 LC-DCP implants (5.5, broad, 10 holes); (3) 2 LCP implants (4.5/5.0, broad, 10 holes) and 4 head locking screws/plate; and (4) 2 CRIF (4.5/5.0) and 10 clamps in alternating position left and right of the rod. All constructs were tested in 4-point bending with a quasi-static load until failure. The implant with the interfragmentary screw was always positioned on the tension side of the construct. Force, displacement, and angular displacement at the "fracture" line were determined. Construct stiffness under low and high loads, yield strength, ultimate strength, and maximum angular displacement were determined. RESULTS: None of the implants failed; the strength of the bone substitute was the limiting factor. At low loads, no differences in stiffness were found among groups, but LCP constructs were stiffer than other constructs under high loads (P=.004). Ultimate strength was lowest in the LCP group (P=.01), whereas yield strength was highest for LCP constructs (409 N m, P=.004). CRIF had the lowest yield strength (117 N m, P=.004); no differences in yield strength (250 N m) were found between DCP and LC-DCP constructs. Differences were found for maximum angular displacement at the "fracture" line, between groups: LPC相似文献   

Bright artificial light at night is associated with increased body mass,poor reproductive success and compromised disease tolerance in Australian budgerigars (Melopsittacus undulatus)

Artificial light at night (ALAN) can cause circadian disruption and result in adverse behavioral and ecological effects in free‐living birds, but studies on captive pet birds as companion animals have been infrequent. We studied the effects of exposure to bright ALAN on body mass, melatonin sulfate levels, reproduction and disease severity in Australian budgerigars (Melopsittacus undulatus) kept in captivity. During the experiment, birds were kept under outdoor temperature, humidity and natural photoperiod from September to December. A total of 48 birds were equally split into 4 groups (6 mating pairs each) and concurrently exposed to ALAN of 200 lux with different duration (0, 30, 60 and 90 min). Monthly observations were recorded for all dependent parameters. ALAN exposure increased mass gain and suppressed melatonin levels in a dose‐dependent manner, especially during December. In addition, ALAN exposure in all duration groups decreased egg production and reduced hatchability from 61% ± 14% in the ALAN‐unexposed control group to 0% in the ALAN‐exposed birds. Disease severity was also found to increase in line with the duration of ALAN exposure. In captive M. undulatus, ALAN exposure was demonstrated to affect photoperiodic regulation with subsequent excess mass gain and reproduction impairment, and increased susceptibility to infections plausibly through duration dose‐dependent suppression of melatonin. To the best of our knowledge, this is the first study to demonstrate a possible association between acute bright ALAN of increasing duration and both natural development of infections as well as reproductive cessation in captive birds. Our findings could be used to improve breeding conditions of captive birds.