抗菌肽在动物生产上的应用

抗菌肽是一类对微生物有抑制作用的多肽,广泛存在于自然界中.抗菌肽具有抗细菌、真菌、病毒、原虫等多种功效,且无残留、无致微生物耐药性.抗菌肽在动物生产上已广泛使用,其优良特性有望取代抗生素.本文总结了抗菌肽的来源、功效及在动物生产上的应用,阐述了抗菌肽在生产和应用存在的主要问题.     

Complex bacterial flora of imported pet tortoises deceased during quarantine: Another zoonotic threat?

Turtoises are a great puzzle when it comes to their bacterial flora, the composition and structure of which are still unknown in details. Its component which has been best described so far is Salmonella spp., presumably due to the threat of reptile-associated salmonellosis in humans. This investigation tried to assess and characterize intestinal bacterial flora of imported tortoises found dead during quarantine. Most of the animals carried various serovars of Salmonella showing no antimicrobial resistance. Presence of multiresistant Escherichia coli was possibly a result of industrial breeding and high usage of antimicrobials. Thirteen bacterial species or genera like Citrobacter spp., Morganella spp., Pseudomonas spp. were identified. Their commensal character is assumed, although pathogenic potential might be verified. The results indicate global tortoise trade as a source of common and exotic bacteria or antimicrobial resistance mechanisms in new geographical areas. These dangers indicate the need for a systematic survey of exotic pets and establishment of legal requirements for reptile health conditions on breeding, trade premises and in households with such pets.     

Biofilms: A role in recurrent mastitis infections?

Mastitis remains one the most important diseases in dairy cattle despite the progress made in improving general udder health in recent years. Epidemiological studies have revealed that following treatment with antimicrobials, bacteriological cure rates vary between 0% and 80% but with no evidence of a significant loss of activity of the major classes of antibiotics licensed for the treatment of bovine mastitis. Recurrent infections are often attributable to biofilm growth of bacteria and this review provides an overview of those mechanisms related to bacterial biofilm growth in mastitis. Biofilm formation is accompanied by significant genetic and subsequent physiological changes in the microorganisms resulting, inter alia, in a loss of sensitivity to virtually all classes of antibiotics.     

规模猪场种猪布鲁氏菌病血清学调查

猪布鲁氏菌病是由猪布鲁氏杆菌（B.suis）引起的流产、睾丸炎等为特征的人畜共患病,危害畜牧业健康与公共卫生安全。为了了解延平区规模猪场种猪布鲁氏菌病感染情况,2013年对23个规模猪场901份血清样品采用琥红平板疑集试验和试管疑集试验进行初检和确诊。结果表明：被检的23个规模猪场有1个猪场检出阳性,被检血清中1份样品阳性,猪场阳性率为4.3%,样品阳性率为0.1%。     

用生物经济模型对我国不同类型猪场的模拟研究——模型的构建和初步结果

根据我国当前养猪生产繁育体系,将我国集约化养猪生产概括为5类典型猪场,并利用农场模型的方法,构建了不同类型猪场的生物经济模型,并考虑了模型的生物学效率。模拟的600头母猪的商品猪场、猪苗场、杂种扩繁场、杜洛克育种场和长白（或大约克）育种场每年总利润分别为56.01、12.99、100.53、134.09和164.10万元,净能利用效率分别为27.69、32.98、28.25、28.32和28.48 MJ/kg。模型还输出了不同类型猪场的成本结构、收入组成和生产综合指标。对模型的敏感度分析表明,模型对不同市场形势、生产水平和管理措施变化的反应是灵敏的。     

疑似高致病性蓝耳病流行病学调查

为了解蓝田县汤峪镇猪疑似高致病性蓝耳病的流行特点、传播途径及发病特点,选取某镇十个村庄的养猪户（场）调查发现,该镇猪疑似高致病性蓝耳病的传播流行以每年高温、高湿时期多发;以直接或者间接接触为主要传播途径,并且以散养、中小规模饲养户、饲养管理粗放的户（场）发病为主;该病可发生于不同年龄、品种、性别的生猪,但以仔猪的发病率、死亡率最高;发病后以抗生素和中成药治疗为主,但其效果欠佳.防制应以紧急免疫、隔离和无害化处理病死猪为主要措施.     

安徽省六安市猪预混料市场营销现状调查和分析

为了解安徽省六安市猪预混料市场营销现状,并为生猪养殖户科学选择预混料以及预混料生产企业制定销售策略提供参考,通过电话调查和走访的方式,对该市生猪养殖场的猪预混料使用情况进行了调查。结果表明：随着猪场养殖年限的增加会提高预混料的使用率;对于不同养殖模式的生猪养殖场,以养殖育肥猪为主的猪场更愿意使用预混料;年出栏育肥猪数量的增加会提高预混料的使用率;合理的价格、稳定的质量、及时的供货以及优惠政策的制订,均有利于维持养殖户对预混料产品的忠诚度。根据调查结果,提出以下建议：预混料厂家应以兽药饲料经销商作为主要分销渠道,将以出售育肥猪为主业且规模较大、养殖时间较长的猪场列为重点目标客户,加强售后服务,同时配合灵活的销售政策,培育忠诚的客户群,不断提高产品的市场竞争力;猪场采购预混料时要选择品牌形象好、价格合理、质量稳定、服务良好的产品。     

Transduction of bla(CMY-2), tet(A), and tet(B) from Salmonella enterica subspecies enterica serovar Heidelberg to S. Typhimurium

Antimicrobial resistance of Salmonella spp., especially resistance mediated by extended spectrum β-lactamases (ESBL), is a growing public health concern. Understanding the mechanisms through which Salmomella spp. acquire the resistance genes can lead to the development of intervention and mitigation strategies. Thirty-one Salmonella isolates of bovine origin were analyzed by serotyping, antimicrobial susceptibility testing, phage induction and bacterial host range determination, and phage transduction of antimicrobial resistance. The Salmonella isolates consisted of 12 serovars. Resistance to 1 or more antibiotics was detected in 12 isolates. Inducible phages were recovered from 19 Salmonella (61%) by spot lysis assay. Of the 19 phage samples, 13 were able to multiply in 2 or more Salmonella of various serovars. A cross-serovar transduction of antimicrobial resistance was observed from S. Heidelberg to S. Typhimurium. Transfection of an antimicrobial-susceptible strain of S. Typhimurium with a phage propagated in a S. Heidelberg resistant to multiple β-lactam antibiotics and tetracycline resulted in independent acquisition of bla_CMY-2, tet(A), and tet(B). These data indicate that inducible phages are common in Salmonella of bovine origin, many of them demonstrate a broad host range, and wild-type phage mediated transduction may contribute to the dissemination of antimicrobial resistance, including the resistance mediated by ESBL.     

Candidate gene expression and intramuscular fat content in pigs

Seventy-two pigs of three genetic groups (Brazilian indigenous breed Piau, Commercial line and Crossbred) of both sexes were slaughtered at four live weights (30, 60, 90 and 120 kg). Intramuscular fat (IMF) content in Longissimus dorsi muscle of each animal was extracted and correlated with candidate gene mRNA expression (ATN1, EEF1A2, FABP3, LDLR, MGP, OBSCN, PDHB, TRDN and RYR1). Within slaughter weight of 120 kg, Piau and Crossbred pigs showed higher IMF content (p < 0.05) than commercial animals, with 2.48, 2.08 and 1.00% respectively. Barrows presented higher values of IMF (p < 0.05) than gilts (1.54 and 1.30% respectively). Gene expression of EEF1A2, FABP3, LDLR, OBSCN, PDHB, TRDN and RYR1 were correlated with IMF (p < 0.05) using the whole dataset. For Piau data only, expression of FABP3, LDLR, MGP, OBSCN, PDHB, TRDN and RYR1 showed correlation with IMF (p < 0.05). Genes that have important roles in lipid transportation inside the cell (FABP3) and tissues (LDLR) showed correlation with IMF of, respectively, 0.68 and 0.63 using the whole data set, and 0.90 and 0.91 using data from Piau animals. The highly positive correlation of the LDLR and FAPB3 expression with IMF content may confirm that these genes are important for fat deposition in the porcine L. dorsi muscle.     

非洲猪瘟对我国生猪养殖的影响

在当前非洲猪瘟疫情形势趋缓和大力恢复生猪产业背景下,为了解我国生猪养殖现状及遇到的问题,以便更好地防控非洲猪瘟,加快恢复生产,2019年8-9月,自行设计调查问卷,结合现场座谈交流,对湖南、河南、重庆、辽宁、安徽等5个省(直辖市)的15个县市196个生猪养殖场(户)开展了调查。结果显示:至2019年9月,调查县市生猪养猪场(户)数较疫情发生前年份减少了50%~80%,生猪饲养模式转变为以自繁自养为主;整体生物安全措施实施率为83.2%,但年出栏500头以下中小规模养殖场(户)的实施率不足70%;被调查生猪养猪场(户)对非洲猪瘟主要传播途径和主要临床症状全部知晓的比例分别为75.0%和73.3%;非洲猪瘟疫情发生以来,88.5%的被调查养猪场(户)防治投入增加,平均每头增加约40元(20~100元);育肥猪、母猪死亡率中值分别为3.0%、5.9%。结果表明:非洲猪瘟疫情对我国各地养殖场(户)的生猪饲养模式产生了较大影响,单纯育肥模式相对减少;养殖场(户)生物安全防护意识、防控知识知晓率明显提高,但小规模养殖场(户)仍存在不足。调查提示,应强化推进规范化养殖场建设,进一步加强对非洲猪瘟防控的宣传与培训。     

蜂胶的作用及其在猪生产中的应用

本文主要介绍了蜂胶的作用及其在猪生产中的应用。     

养殖企业从业人员“动物福利”社会态度研究

1 525份有效问卷的调查表明,中国畜牧行业大多数从业人员对动物福利有基本的认知。如75.4%的从业人员听说过动物福利,76.5%的从业人员赞成就动物福利立法,强迫生产者为猪鸡提供良好的生长和生存条件等。从业人员普遍认同动物的生理福利和环境福利,但对行为福利等却认知不足。从业人员在赞同动物福利的同时,又不太愿意因推行动物福利而承担过大的成本,如59.8%的从业者只愿意承担因遵守动物福利而导致5%及以下的成本增加。     

非洲猪瘟影响下我国生猪产品贸易现状

我国是全球最大的猪肉生产贸易国,猪肉进口量约占全球总量的三分之一.受非洲猪瘟疫情影响,我国猪肉产量大幅下降,猪肉进口量进一步增加,猪肉进口额由2017年的22.2亿美元涨至2019年的46.6亿美元;大豆、玉米等主要饲料进口额近三年增长了4～14亿美元.本文分析了国内需求、国际畜产品价格、进口关税、其他贸易国生产消费等...