Mange in pigs: A survey

Extract

Mange in pigs caused by Sarcoptes scabiei var. suis is reported to be common in New Zealand, but, to the writer's knowledge, no investigation has been made of the number of infested farms in any area.     

Clinical use of a ceramide-based moisturizer for treating dogs with atopic dermatitis

In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms.     

猪繁殖与呼吸综合征病毒垂直传播及其危害研究进展

猪繁殖与呼吸综合征病毒(PRRSV)感染引起的繁殖障碍在妊娠早期表现为母猪受胎率低、不规律返情及孕早期流产;怀孕后半期流产、早产,产死胎、木乃伊胎及弱仔等。先天感染的仔猪抵抗继发感染的能力低,可持续排毒并感染周围的阴性动物。PRRSV穿过胎盘屏障感染胎儿很可能是经巨噬细胞/单核细胞介导的,并在母胎界面造成病理损伤,病毒在胎儿着床点的复制可能是导致胎儿死亡和母猪流产的原因。预防PRRSV垂直传播必须控制母猪感染PRRSV,缩短已感染母猪的病毒血症持续时间,此外,通过生物安全、限制猪群流动和严格的消毒措施控制水平传播,通过疫苗免疫和药物保健消除易感动物。作者概述了妊娠各阶段母猪感染PRRSV发生垂直传播的情况及其后续的繁殖障碍。     

长期不同施肥处理对连作高粱生长规律及产量的影响研究

以甜高粱品种‘新高粱3号’为试验材料,采用长期定位施肥方式,研究CK、NK、NP、PK、NPK、M(有机肥)、NPKM、1.5NPKM 8个不同施肥处理对甜高粱生长规律、含糖锤度、叶绿素含量及产量的影响,筛选出适宜新疆干旱区连作甜高粱生长的最佳施肥方式。结果显示,不同施肥处理对连作甜高粱的生育期、农艺性状、叶绿素含量、秸秆含糖锤度及产量均有影响。在不同施肥处理下甜高粱的株高、茎粗、叶片数、秸秆含糖锤度和叶绿素含量在整个生育阶段的变化趋势基本一致,但不同施肥处理之间有差异。成熟期不同施肥处理之间的株高、茎粗和茎秆含糖锤度差异较大、叶片数差异不大,其中NPKM施肥处理的株高、茎粗和含糖锤度分别为224.33 cm、21.47 mm、18.41%,均高于其他施肥处理,并比CK极显著增高了13.86%、39.60%、23.47%。施肥有利于秸秆含糖锤度的积累,在抽穗后第28天时达到最高值,此时,NPKM处理达到18.57%,但抽穗期到成熟期不同茎节含糖锤度在不同施肥处理下的积累规律不一致。各处理的叶绿素含量在整个生育期的变化趋势基本一致,灌浆期时达到最大值,其中NPKM处理叶绿素达到44.62 SPAD。所有施肥处理的秸秆产量、籽粒产量和生物产量均比CK极显著地增加,其中NPKM处理秸秆产量、籽粒产量、生物产量分别达到90.80、4.01、94.81 t·hm^-2,均高于其他处理。施肥有利于增加甜高粱的产量、含糖锤度及经济效益,利用不同施肥方式来缓解高粱连作障碍的过程中应当注重采取不同的肥料配比。综合来看,有机肥、无机肥混合施用(NPKM)是促进干旱区连作高粱生长发育的最佳施肥模式。     

成年母鸡松果腺组织结构的研究

用透射与扫描电镜和荧光显微镜对25只成年母鸡的松果腺进行了系统观察。松果腺主要由松果体细胞组成,其间夹杂有少量胶质细胞。松果体细胞的核呈圆形或椭圆形,而胶质细胞的核多呈不规则形。松果体细胞具有突起,线粒体丰富,高尔基复合体发达,胞质中散布有核糖体,并见有粗面和滑面内质网、微管、溶酶体、脂滴以及少量致密核芯小体和板层小体。胶质细胞的结构特征为胞质中含有微丝。毛细血管内皮不含窗孔。本研究结果表明,鸡松果体细胞具有内分泌细胞的结构特征,因而认为鸡的松果腺是一个内分泌腺。     

西北灌区薯/豆连续套作对系统产量及土壤肥力的影响

探求马铃薯/大豆连续套作下复合群体产量优势,为实现持续高产的生产目标提供理论和技术依据。2011-2014年,在西北沿黄灌区会宁县郭城镇,选用马铃薯品种克新4号和大豆品种冀豆17作为试验材料,设置马铃薯连作(PM)、大豆连作(SM)、薯-豆轮作(P-S)、薯/豆套作连作(IC)和薯/豆套作轮作(IR)5种种植方式开展大田定位试验,研究不同种植模式连续种植4年对系统产量及产量构成的影响,分析系统生产力及土壤肥力的变化特点,进而揭示薯/豆套作系统的生产价值。结果表明, 1)薯/豆套作具有明显的产量优势,4年间,IC和IR系统产量与连作相比,分别提高了28.54%~254.07%和39.39%~283.98%,与轮作相比,分别提高了57.51%和70.81%。2011和2012年,IC与IR系统产量间差异不显著,但IC和IR与PM、SM、P-S处理间系统产量差异达到显著水平(P<0.05),2013和2014年IR系统产量均最高,分别达到9912.79和9589.90 kg/hm²,较IC处理分别提高了15.38%和8.45%,且与其他处理间均差异达到显著水平(P<0.05)。2)不同种植模式在年际间变化显著,对于PM,2012年(连作1年)与2011年(正茬)产量差异不显著,而2013年(连作2年)和2014年(连作3年)产量较2011年分别下降了22.07%和42.11%;SM和IC变化趋势与PM表现一致,连作2年后,降幅分别为31.15%~53.60%和13.91%~24.17%;对于P-S和IR而言,年际间系统产量无显著变化。3)不同种植模式对耕层土壤肥力性质指标的影响程度是:有效磷>碱解氮>全氮>全磷>速效钾>有机质>全钾>pH。较PM、SM和P-M,IC和IR连续套作4年,耕层土壤全氮、全磷、全钾、碱解氮、有效磷和速效钾呈下降趋势,尤其是有效磷和速效钾,下降幅度分别达到26.24%~42.87%和18.48%~30.22%。马铃薯和大豆连作2年后产量显著下降,薯/豆连续套作4年(IC或IR),相对于连作或轮作具有明显的生产力优势,尤其是薯/豆套作轮作模式,基于养分吸收量的增加和养分利用效率的提高,连续4年系统产量相对稳定。     

Genetic diversity,anti‐microbial resistance,plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.