一起野禽H5N8亚型禽流感疫情的处置与思考

2021年1月,江苏省连云港市云台山景区云台街道西隅水库发生一起疑似野禽H5N8亚型禽流感疫情,共17只鸳鸯、大雁感染死亡。江苏省动物疫病预防控制中心迅速组织相关人员,指导连云港市按照国家相关方案和规范要求,开展现场调查、实验室诊断和应急处置工作。经江苏省动物疫病预防控制中心初诊,国家禽流感参考实验室确诊,诊断为H5N8亚型高致病性禽流感疫情。同时,指导当地政府划定疫点、疫区和受威胁区,封锁相关区域,开展应急监测、紧急流行病学调查、全面消毒等应急处置工作。经果断处置,疫情得到了有效控制,未造成扩散和蔓延。本次疫情提示：野禽疫情的早期发现和及时控制对于降低疫情扩散风险至关重要;林业和农业农村部门的沟通协作要继续加强,日常的禽流感监测力度需要进一步加大,家禽的禽流感疫苗免疫要更加科学,群众的禽流感防控意识要持续提高。     

甘肃省天水市生猪屠宰企业非洲猪瘟检测能力提升措施

着力加强和提升生猪屠宰企业非洲猪瘟检测实验室建设是有效防范非洲猪瘟传播的重要手段。为进一步提升屠宰企业非洲猪瘟自检能力,对甘肃省天水市生猪屠宰企业非洲猪瘟自检体系建设和运行情况进行了实地调研,并针对不足之处提出系列提升指导措施。调研发现:2019年以来,通过优化实验室配置、增加检测人员数量、加强检测人员培训和强化生物安全防护措施等,天水市屠宰企业非洲猪瘟检测能力明显提升。本文为我国其他地区生猪屠宰企业提升非洲猪瘟自检能力提供了参考。     

琥珀酸黄杆菌促生机理及其对多年生黑麦草生长和抗逆性的生理调控作用

为探究琥珀酸黄杆菌（Flavobacterium succinicans）对非生物胁迫下多年生黑麦草（Lolium perenne）的缓解效应,本试验研究了菌株DSM4002的生物学特性,并在盆栽条件下,分析了干旱（维持相对含水量（30±5）%处理7 d和14 d）、低温（4℃处理3 d和7 d）和盐胁迫（150 mM NaCl处理5 d和10 d）下根际接种DSM4002对多年生黑麦草生长和生理特性的影响。结果表明,DSM4002具有分泌吲哚乙酸（Indole-3-acetic acid,IAA）、溶磷和产铁载体能力,对壮观霉素、卡那霉素等具有抗性,对氯霉素敏感。同时,接种DSM4002能够提高正常生长、干旱、低温和盐胁迫下多年生黑麦草的生物量、抗氧化酶活性、可溶性糖和脯氨酸含量,降低相对电导率和丙二醛（Malondialdehyde,MDA）含量。综上,琥珀酸黄杆菌促进多年生黑麦草的生长与其自身具有分泌IAA、溶磷和产铁载体能力有关,而且它能够调节植物体内氧化还原平衡,从而增强多年生黑麦草的抗旱、抗寒和抗盐能力。     

断奶仔猪日粮高剂量氧化锌的替代技术研究进展

氧化锌是断奶仔猪阶段饲料中防止腹泻的常用饲料添加剂,但是它的使用会造成环境污染。农业农村部也逐渐开始对氧化锌在养猪生产中的使用加以限制。此次研究从氧化锌的抗腹泻机理、不同的锌源和改变氧化锌的生物活性、氧化锌来源、植物乳杆菌、植物精油、水解单宁(HT)和氧化锌联合使用、猪免疫球蛋白G(pplgG)等方面进行综述,探讨其替代思路,以期为断奶仔猪高剂量氧化锌替代提供参考。     

副猪嗜血杆菌病的临床症状与防治

副猪嗜血杆菌病是一种急性、典型猪传染病,对生猪生长发育的各个阶段都会产生不良影响,对膘情较好的保育阶段仔猪影响最为严重。由于副猪嗜血杆菌血清型多且细菌易产生耐药性,导致诊治困难。目前该病发病率日渐上升,为避免养猪生产因此造成巨大经济损失,需要结合日常预防和治疗,避免此病出现并进一步发展。文章综合叙述了副猪嗜血杆菌病原学、流行病学、临床病变及综合防治,以期为该病的防控与治疗提供参考。     

Green tea polyphenols supplementation alters immunometabolism and oxidative stress in dairy cows with hyperketonemia

Peripartal cows often experience negative energy balance, and are therefore prone to suffering from metabolic diseases such as hyperketonemia, which causes financial losses in dairy farms. This study aimed to investigate the effect of green tea polyphenol (GTP) supplementation during the periparturient period on production performance, oxidative stress and immunometabolism in dairy cows with hyperketonemia. One hundred Holstein cows were assigned to GTP (0.2 g/kg DM; n = 50) or control (without GTP; n = 50) group based on body weight, previous milk yield, and parity on d 15 before expected parturition. Subsequently, 10 cows with hyperketonemia were selected from each group, according to blood β-hydroxybutyric acid (BHBA) concentration between 1.2 and 2.9 mmol/L from 2 to 3 d postpartum. All cows were fed a close-up diet and a lactation diet with or without GTP supply from 15 d prepartum until 30 d postpartum. Milk and blood samples were obtained from 20 cows selected with hyperketonemia on 10, 20, and 30 d postpartum. Compared with control cows, greater milk yield and lower somatic cell count were observed in GTP cows. The GTP group had lower concentrations of BHBA, free fatty acids, cholesterol, triglyceride, reactive oxygen species, malondialdehyde, and hydrogen peroxide, greater concentrations of glucose, lower activities of aspartate aminotransferase, alanine aminotransferase, and glutamyl transpeptidase, alongside greater activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. Additionally, GTP supplementation up-regulated concentrations of interleukin-6 and interleukin-10, but down-regulated concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-2, interleukin-8, and interferon-γ in plasma. Greater concentrations of plasma immunoglobulin G were also detected in the GTP group. Overall, the data suggested that GTP supplementation from 15 d prepartum to 30 d postpartum improved the milk yield and health status in cows with hyperketonemia during early lactation.     

木耳菌棒力学性能试验

以经过栽培的木耳菌棒为试验材料,在万能试验机上对不同含水率的菌棒试样进行剪切、压缩的力学性能试验。试验结果表明:含水率是影响菌棒剪切强度、抗压强度的重要自然因素。平均含水率分别为11.75%,21.16%,27.68%的菌棒其平均剪切强度分别为29.4k Pa、20k Pa、14.5k Pa。平均含水率分别为14.3%,24%的菌棒,其平均抗压强度分别为144.7k Pa、77.7k Pa。菌棒的含水率与剪切强度,抗压强度均呈幂指数关系。这些都为研制菌棒粉碎机械、选择粉碎参数提供了设计依据。     

基于高斯自适应拟合的苹果目标分割方法研究

苹果目标的准确识别是苹果机械化采摘需要解决的关键问题之一。为此,基于YUV颜色空间模型,提出了一种结合色差分量与高斯自适应拟合算法的苹果目标分割方法。该方法采用首先将苹果目标由RGB颜色空间转换至YUV颜色空间,并利用色差分量V建立果实与背景分割的高斯分布拟合模型,根据拟合结果自动获取分割阈值,以实现自然场景下苹果目标的准确分割。为了验证文中算法的有效性,利用多幅图像进行了试验并与Otsu自适应阈值分割算法进行了比较。试验结果表明,采用文中算法得到的苹果果实的平均检出率达87.08%,识别率领先Otsu算法9.91%。因此,对于着色度较为均匀的苹果目标,采用高斯自适应拟合方法可以有效提高其识别率。     

枸杞的微波干燥特性及其对品质的影响

为了缩短枸杞的干燥时间、节约干燥成本,运用微波试验装置,通过选择不用的干燥功率和物料铺放厚度,研究了枸杞微波干燥特性及其对干燥后产品品质的影响。研究结果表明:微波干燥作用于枸杞干燥降速干燥阶段可以大幅缩短枸杞干燥周期,微波组合干燥较自然晾晒缩短时间约65h,约占自然晾晒干燥周期的72%;干燥功率和物料层厚度是影响微波干燥时间的重要因素,微波功率越大,物料层厚度越小,则物料干燥时间越短;不同的微波干燥参数对干后产品品质有不同影响,微波功率为1k W,当物料层厚度平铺为2cm时,干燥后产品多糖保存率和感官品质最好。     

Isolation and characterization of antimicrobial-resistant Escherichia coli from national horse racetracks and private horse-riding courses in Korea

Limited information is available regarding horse-associated antimicrobial resistant (AR) Escherichia (E.) coli. This study was designed to evaluate the frequency and characterize the pattern of AR E. coli from healthy horse-associated samples. A total of 143 E. coli (4.6%) were isolated from 3,078 samples collected from three national racetracks and 14 private horse-riding courses in Korea. Thirty of the E. coli isolates (21%) showed antimicrobial resistance to at least one antimicrobial agent, and four of the AR E. coli (13.3%) were defined as multi-drug resistance. Most of the AR E. coli harbored AR genes corresponding to their antimicrobial resistance phenotypes. Four of the AR E. coli carried class 1 integrase gene (intI1), a gene associated with multi-drug resistance. Pulsed-field gel electrophoretic analysis showed no genetic relatedness among AR E. coli isolated from different facilities; however, cross-transmissions between horses or horses and environments were detected in two facilities. Although cross-transmission of AR E. coli in horses and their environments was generally low, our study suggests a risk of transmission of AR bacteria between horses and humans. Further studies are needed to evaluate the risk of possible transmission of horse-associated AR bacteria to human communities through horse riders and horse-care workers.