个人养犬应注意什么

当今社会经济高速发展,人民生活水平不断提高,业余生活也日益丰富多彩,作为六畜之一的犬,自古以来就被广大城乡群众接受并喜爱,在国外甚至有巨额财产馈赠爱犬的也不乏其人。作为一名业余爱犬人士,我想谈谈自己的爱犬心得,主要从以下六个方面来论述并与大家交流：     

肉兔不同杂交组合的生产性能测定

养兔具有投资少、见效快、效益高的特点，饲养规模可大可小，饲养方式多种多样，是当前广大农村实现农业增效、农民增收的好项目。但是，养兔效益可受品种、繁育方式、饲料营养、饲养管理等多种因素的影响。据生产实践，作为商品兔，一般杂种兔的经济效益高于纯种兔，杂种后代的增重速度可比纯种兔提高10％以上。但不同品种间杂交，其杂交效果各不一样。     

Bayesian structural equation models for inferring relationships between phenotypes: a review of methodology, identifiability, and applications

Structural equation models provide a general statistical modelling technique for estimating and testing relationships among variables. Such relationships are often not revealed by standard linear models, but are of importance for understanding mechanisms underlying e.g., production-related diseases, such as mastitis. This paper gives a review of Bayesian structural equation models concerning methodology and identifiability, focused on animal breeding and genetics modelling. Applications of this type of methods in animal breeding are also reviewed critically, with discussion on advantages and disadvantages of these approaches.     

重新认识农区山羊放牧饲养

文章从山羊养殖历史、生物学特性、自然社会、经济效益、生态环保、市场消费及国外养殖进展等方面进行研究,认为我国南方农区山羊饲养应回归放牧养羊,可以实现社会生态经济的可持续发展。同时提出放牧养殖的标准化建设思路。     

猪圆环病毒2型和猪瘟病毒抗体检测与分析

目的检测临汾市某县猪圆环病毒2型(PCV2)和猪瘟病毒(CSFV)的抗体水平.方法分别从该县的企业、散户、大户的猪只中采集血清186份,应用ELISA方法检测抗体水平.结果 PCV2抗体阳性率平均为83.33%,CSFV抗体阳性率平均为54.83%.结论该县猪圆环病毒2型感染严重,猪瘟疫苗免疫抗体水平偏低,与猪瘟疫苗使用不当、猪圆环病毒2型感染存在一定关系.     

A dominant antigenic epitope on SARS-CoV spike protein identified by an avian single-chain variable fragment (scFv)-expressing phage

Severe acute respiratory syndrome (SARS) is a newly emergent human disease, which requires rapid diagnosis and effective therapy. Among antibody sources, immunoglobulin Y (IgY) is the major antibody found in chicken eggs and can be used as an alternative to mammalian antibodies normally used in research and immunotherapy. In this study, phage-expressing chicken monoclonal scFv antibody was chosen and characterized with phage display antibody technology. Truncated fragments of SARS-CoV spike protein were cloned in pET-21 vector and expressed in BL-21 Escherichia coli (E. coli) cells. After purification, the purity of these recombinant spike proteins was examined on SDS-PAGE and their identity verified with Western blot analysis using anti-his antibodies and sera from convalescent stage SARS-CoV-infected patients. Using these bacteria-derived proteins to immunize chickens, it was found that polyclonal IgY antibodies in the egg yolk and sera were highly reactive to the immunogens, as shown by Western blot and immunocytochemical staining analysis. A phage displaying scFv library was also established from spleen B cells of immunized chicken with 5 x 10(7) clones. After four panning cycles, the eluted phage titer showed a 10-fold increase. In sequence analysis with chicken germline gene, five phage clones reacted, with large dissimilarities of between 31 and 62%, in the complementarity-determining regions, one dominant phage 4S1 had strong binding to fragment Se-e, located between amino acid residues 456-650 of the spike protein and this particular phage had significantly strong binding to SARS-CoV-infected Vero E6 cells. Based on the results, we conclude that generating specific scFv-expressing phage binders with the phage display system can be successfully achieved and that this knowledge can be applied in clinical or academic research.     

Yeast-derived sigma C protein-induced immunity against avian reovirus

Avian reoviruses (ARVs) can result in disease and economic losses in the poultry industry. Vaccines against ARV may not provide full protection and can cause adverse reactions. The coding sequence of the sigma C protein from strain S1133 of avian reovirus was expressed in Schizasaccharomyces pombe. Sigma C protein expression was demonstrated by Western blotting, and the protein was evaluated for its ability to protect specific-pathogen-free (SPF) chickens against challenge with the virulent S1133 strain. Serologic and challenge-infection data showed the efficacy of the recombinant vaccine administered orally each week for 3 consecutive wk. Sigma C protein induced antibody, as determined by enzyme-linked immunosorbent assay. Percentage (%) protection induced by the low dose (125 microg purified yeast-expressed sigma C protein/chicken) or the high dose (250 microg purified yeast-expressed sigma C protein/chicken) was 64 and 91, respectively. The commercial vaccine administered once or twice provided 82% protection. Results supported the feasibility of a plant-derived vaccine for use in poultry immunization schemes.     

不同的干燥工艺对荷花蜂花粉功能成分的影响

探讨了5种干燥工艺对荷花蜂花粉功能成分的影响。微波干燥的干燥效率最高,60%火力处理540s可使水分从31.41%降到6.42%;干燥方式对荷花蜂花粉蛋白质影响较小;微波干燥后总黄酮提取率最高,为13.20mg/g;真空冷冻干燥后维生素C和过氧化氢酶含量最高,分别为48.89mg/100g和29.86mg/g·min。总的来说,真空冷冻干燥对荷花蜂花粉的功能成分影响最小;常压恒温干燥对功能成分影响较小、工艺简单、对设备要求低,宜于大规模应用于实际生产中。     

Development and characterization of monoclonal antibodies to subgroup A avian leukosis virus

Avian leukosis virus subgroup A (ALV‐A) is a retrovirus which infects egg‐type chickens and is the main pathogen of lymphoid leukosis (LL) and myeloid leukosis (ML). In order to greatly enhance the diagnosis and treatment of clinical avian leukemia, two monoclonal antibodies (MAbs) to ALV‐A were developed by fusion between SP2/0 and spleen cells from mice immunized with expressed ALV‐A env‐gp85 protein. Using immunofluorescence assay (IFA), two MAbs reacted with ALV‐A, but not with subgroups B and J of ALV. Western blot tests showed that molecular weight of ALV‐A envelope glycoprotein recognized by MAbs was about 53 kD. Isotyping test revealed that two MAbs (A5C1 and A4C8) were IgG1 isotypes. These MAbs can be used for diagnosis and epidemiology of ALV‐A.     

重要营养素--血红素铁

血红素铁是卟啉类化合物,是哺乳动物血液中的天然色素和生物铁,广泛应用于医药、食品和化工业。文章就血红素铁的理化特性、生理功能及应用进行了简述,并对其常用提取方法进行了比较概述。