放牧对青海湖北岸高寒草原植物群落特征的影响

基于青海湖北岸高寒草原连续3年放牧控制试验,研究了暖季和冷季放牧草地植物群落特征的变化。结果表明,暖季和冷季放牧草地群落地上生物量均随放牧强度的增加呈现下降趋势,禾本科地上生物量的变化趋势基本与群落地上生物量的一致;中度放牧对暖季放牧草地植被的影响程度高于冷季放牧草地;围栏封育区和冷季重度放牧草地的优势种均为紫花针茅(Stipapurpurea)和矮嵩草(Kobresia humilis),暖季放牧各放牧小区和冷季放牧草地轻度和中度放牧处理优势种均为紫花针茅和披针叶黄华(Thermopsis lanceolata);随放牧强度的增加,暖季放牧草地群落物种多样性指数和均匀度指数表现出先降低后增加的趋势,冷季放牧草地群落物种多样性指数和均匀度指数表现出增加的趋势,但是多样性指数在暖、冷季放牧草地均以重度放牧区最高。     

Detection of chromogranin A in the adrenal gland extracts of different animal species by an enzyme-linked immunosorbent assay using Thomsen-Friedenreich antigen-specific Amaranthus caudatus lectin

The reactivity of different lectins with crude chromogranin A (CgA) obtained from different animals, namely, cow, horse, dog, pig, and dolphin, was examined to identify lectin(s) that would be useful as coating reagent(s) in a sandwich enzyme-linked immunosorbent assay (ELISA). Of the different lectins studied, the Amaranthus caudatus lectin (ACA), which is specific for the Thomsen-Friedenreich (T)-antigen (Galβ1-3GalNAc), was found to react with the CgA from different animals by western blotting. Purified rabbit anti-bovine CgA antibody was also found to cross-react with the crude CgA preparations. On the basis of these findings, a sandwich ELISA was developed with ACA as the coating reagent and anti-bovine CgA antibody as the probing antibody. Using this method, concentration-dependent curves ranging from 0.003 μg/mL to 25 μg/mL and from 0.02 μg/mL to 25 μg/mL were obtained for bovine CgA and canine CgA, respectively. Similarly, concentration-dependent curves were obtained for the equine, swine, and dolphin crude CgA extracts. Thus, ACA is concluded to be a valuable reagent for CgA detection in crude extracts from different animal species, and for CgA isolation/purification.     

城区宠物防疫管理

合肥是安徽的省会城市,随着人民生活水平的提高,城区养犬数量急剧增加,现仅合肥二环以内就有犬5万只左右。部分市民不文明养犬,随意遗弃犬,使得流浪犬数量增加,造成犬病的传播。一些动物诊所和宠物     

Prevalence of feline calicivirus and the distribution of serum neutralizing antibody against isolate strains in cats of Hangzhou,China

BackgroundFeline calicivirus (FCV) is a common pathogen of felids, and FCV vaccination is regularly practiced. The genetic variability and antigenic diversity of FCV hinder the effective control and prevention of infection by vaccination. Improved knowledge of the epidemiological characteristics of FCV should assist in the development of more effective vaccines.ObjectivesThis study aims to determine the prevalence of FCV in a population of cats with FCV-suspected clinical signs in Hangzhou and to demonstrate the antigenic and genetic relationships between vaccine status and representative isolated FCV strains.MethodsCats (n = 516) from Hangzhou were investigated between 2018 and 2020. The association between risk factors and FCV infection was assessed. Phylogenetic analyses based on a capsid coding sequence were performed to identify the genetic relationships between strains. In vitro virus neutralization tests were used to assess antibody levels against isolated FCV strains in client-owned cats.ResultsThe FCV-positive rate of the examined cats was 43.0%. Risk factors significantly associated with FCV infection were vaccination status and oral symptoms. Phylogenetic analysis revealed a radial phylogeny with no evidence of temporal or countrywide clusters. There was a significant difference in the distribution of serum antibody titers between vaccinated and unvaccinated cats.ConclusionsThis study revealed a high prevalence and genetic diversity of FCV in Hangzhou. The results indicate that the efficacy of FCV vaccination is unsatisfactory. More comprehensive and refined vaccination protocols are an urgent and unmet need.     

自然灾害期间的动物疫病防控浅析

自然灾害对动物疫病有严重的影响,可使饲养环境、饮用水资源等遭到破坏,而且使疫病加速传播。本文对灾害对微生物群落的影响及如何开展灾后动物疫病的防控措施作以简要介绍,包括及时处理死亡畜禽、做好灾后消毒、开展免疫检疫、完善应急机制、加强畜禽饲养管理、重视人员安全防护等内容,以期为灾后动物疫病的防控提供指导。     

益生素在配合饲料中的应用技术研究

益生素可以活菌及其产物形式直接用于饲喂畜禽,其能够协调畜禽消化系统微生物平衡,补充畜禽体内的有益生理性菌群或正常菌群,从而提高畜禽免疫力、抗病力以及日粮消化率,进而达到防病治病和促生长的双重作用.就益生素在配合饲料中的应用研究与生产技术进行了综述.     

过表达桑树色氨酸脱羧酶基因(MnTDC)转基因烟草提高其耐盐性

褪黑素在植物生长、发育、生物与非生物胁迫中发挥重要作用。色氨酸脱羧酶(tryptophan decarboxylase, TDC)是褪黑素生物合成中第一个重要的酶。本研究克隆川桑TDC基因,并将其转入烟草中过表达,探讨MnTDC在盐胁迫下的作用机制。结果表明,成功构建过表达载体pLGNL-MnTDC,并经过农杆菌介导的愈伤组织转化获得3个独立转基因系。GUS染色、基因组PCR鉴定证明MnTDC成功转化到烟草株系中。qRT-PCR结果表明MnTDC在3个转基因烟草株系中的转录水平显著高于野生型(WT)。UPLC-MS/MS结果表明转基因株系显著提高了褪黑素的生物合成量。盐胁迫下,MnTDC过表达烟草与野生株系烟草相比,耐盐性显著增强。转基因烟草株系中的过氧化氢酶(CAT)、超氧化物歧化酶(SOD)及过氧化物酶(POD)活性均显著高于野生株系烟草,脯氨酸(Pro)等调节渗透压物质的含量和ERD10C等调节渗透压的基因表达量显著高于野生株系烟草,转基因株系中丙二醛(MDA)含量比野生株系烟草低。研究结果表明,MnTDC通过调节烟草细胞中褪黑素的含量进而影响了烟草植株整体的耐盐性。本研究初步揭...     

2018年安徽省部分地区A型禽流感流行率横断面研究

为了解安徽省A型禽流感病毒感染情况,2018年4—5月,在安徽省北部、中部和南部7个市,随机选取各类型场点173个,在每个场点内随机采集35份咽喉/泄殖腔和环境拭子样品,使用荧光RT-PCR进行A型、H5亚型、H7亚型流感病毒核酸检测。结果显示：在4个养殖场、3个活禽批发市场和17个农贸市场检出了A型禽流感病毒,场点阳性率分别为2.9%（4/140）、75.0%（3/4）、80.9%（17/21）,未检出H5和H7亚型流感病毒核酸;A型禽流感群体流行率为11.2%（95%CI：6.5%~15.8%）,个体流行率为1.2%（95%CI：0.9%~1.5%）;活禽交易市场内,禽群感染A型禽流感病毒的风险较高（OR=136,95%CI：32.7~549.4）。结果表明,A型禽流感病毒在养殖和交易环节存在一定的污染,而在活禽交易市场的污染更严重,是今后禽流感防控的重点,需继续加强活禽交易市场的管理和消毒灭源工作。     

基于案例的国内动物疫病风险评估技术发展现状研究

为了解我国动物疫病风险评估研究进展,本研究对我国2006—2016年间发表的动物疫病风险评估模型相关文献进行分析。采用文献回顾的方式,就动物疫病风险评估模型的构建目标、构建方法、评估对象、模型结构及实际应用进行研究。研究表明,我国动物疫病风险评估模型研究与国际基本同步,但也存在理论体系研究薄弱、理论联系实际不足等问题。同时,提出了完善理论体系建设、推广模型应用等建议。     

Effect of dietary supplemental nicotinic acid on growth performance,carcass characteristics and meat quality in three genotypes of chicken

The effects of dietary supplemental nicotinic acid (NA) on growth performance, carcass characteristics and meat quality were investigated in three genotypes of chicken. Fast‐growing AA (Arbor Acres) broilers were compared with two genotypes of a slow‐growing local breed, Beijing‐You, that had undergone selection for and against intramuscular fat content respectively (BJY+IMF and BJY?IMF). The treatments were arranged 3 × 4 factorial completely randomized design. Day‐old females (n = 624) were allocated to four treatments with six replicates per treatment and fed diets (basal contained ～25 mg NA/kg) supplemented with 0, 30, 60 and 120 mg NA/kg. A sample of 72 birds from each genotype was slaughtered at market time (8 weeks of age for AA and 16 weeks of age for BJY). The breast muscles of AA broilers were darker, had less redness and yellowness, lower drip loss and higher shear force as compared to the BJY genotypes (p < 0.01). The highest drip loss and the lowest shear force among the three genotypes were apparent in BJY+IMF (p < 0.01). Increasing supplementation from 0 to 60 mg NA/kg tended to increase average daily gain (ADG), average daily feed intake, width of intermuscular fat band, thickness of subcutaneous fat (including skin) and percentage of abdominal fat but, for most variables, values decreased slightly with 120 mg NA/kg. Increasing supplementation to 60 mg NA/kg decreased (quadratic, p < 0.001) drip loss, but it increased at 120 mg NA/kg. The present results indicate that (i) the AA broilers fed corn–soybean meal based‐diets require approximately 60 mg NA/kg to maximize ADG and meat product yield and decrease the drip loss of breast muscle; (ii) the addition of 30 mg NA/kg meets the requirement of BJY genotypes; and (iii) there seems to be no beneficial effect of NA supplementation on chicken meat quality except for limiting the drip loss.