试论热应激对犬的影响

犬的一生总是处在一定的环境之中,以各种方式与环境之间发生联系并互相影响,不适的环境就会刺激犬产生应激.应激是指犬对各种非常刺激所产生的全身非特异性应答反应的总和.在养犬过程中,引起犬应激的因素和环节很多,根据应激源不同可分为很多种,如热应激、冷应激、运输应激、断奶应激、转群应激等.犬的汗腺不发达,通过出汗的形式散热很微弱,皮下脂肪又较厚,不利于热量散发,所以犬对高温十分敏感,因高温引起的热应激对犬影响最大,也最常见.本文针对热应激对犬的影响以及预防措施作一论述.     

冷应激对海兰雏鸡某些血相变化的影响

冷应激（cold stress）给北方或寒冷地区的畜牧业带来了较大损失，特别是常引起畜禽幼仔免疫力下降、抗病能力低下、死亡率升高。寒冷属于应激源之一，有关冷应激对免疫的影响也有许多研究。由于研究者们所采用的动物不同，应激方式、强度、作用时间不同，所测指标不同，结果也不尽相同。一般来说，急性冷应激刺激常呈现免疫抑制，而慢性冷应激常引起免疫增强；应激强度不同引起的免疫反应也不同，     

冷应激对贵妃雏鸡外周血白细胞分类及T淋巴细胞变化的影响

寒冷属于应激源之一,有关冷应激（cold stress）对免疫的影响已有许多研究。由于研究者们所采用的动物不同,应激的方式、强度、作用时间不同,所测指标不同,结果也不尽相同。笔者以前曾探讨了不同冷应激强度和作用时间对家禽免疫力的影响,但是对珍禽还未见相关资料报道。试验以贵妃雏鸡为研究对象来研究冷应激对其血相变化的影响,为研究冷应激对珍禽免疫力变化的影响提供试验数据。     

畜禽运输应激的防范措施

随着畜牧养殖业的高度集约化发展,畜禽应激综合症发病率不断上升,畜禽应激的危害正日益突出并已成为阻碍畜牧业发展的最活跃的因素之一.同时,随着国内外畜禽贸易的繁荣,运输畜禽日益增多,由于晕车,高湿,高温,挤压,踩踏,饥饿,缺水等作用下应激引起畜禽发病、死亡或致残所造成的经济损失是巨大的.此外,运输应激还可使畜禽肉质下降,如呈现PSE猪肉(苍白、柔软、渗水的猪肉)、DFD猪肉(深色硬干肉);亦可使经由运输过的畜禽体重有不同程度的减轻.本文总结了防范畜禽运输性应激的几种措施.     

鸡的应激反应及防治措施

随着集约化规模化养禽业的发展,产生应激是不可避免的,消除应激是不可能的,但减轻应激,尽量降低应激所带来的损失却是高效生产所必需的.应激反应是机体在长期进化过程中形成的一种扩大适应范围的生理反应,是一种生物学特殊的生理状态.鸡群受应激影响,采食量下降,体重减轻,生长缓慢,给养鸡业带来一定经济损失.因此,解决这一影响畜牧业生产中的难题,目前已成为营养生理、家畜环境、营养学研究的前沿和热点.     

复合抗热应激添加剂对肉鸡的影响及其作用机理研究

随着畜牧养殖业的高度集约化发展，家禽面临越来越多的各种应激因素的挑战。其中环境高温所造成的应激给家禽生产带来巨大的经济损失。肉鸡、蛋鸡对高温非常敏感，其中肉鸡更为突出。在高温高湿条件下，肉鸡表现为生产性能显著下降、自身免疫机能低下、发病死亡率升高。为缓解或消除应激所带来的不利影响，国内外学者做了大量研究工作，但大多仅使用单一的抗应激剂，由于应激对肉鸡的影响是多方面的，不同的应激对肉鸡的影响是不同的，单一抗应激添加剂作用有限，不可能完全或最大程度地消除或缓解应激，因此研制和开发复合抗应激添加剂产品…     

肉类联合加工厂中猪应激综合征的研究

应激是机体应答外界环境的强烈刺激和各种伤害因素—应激原—的作用所产生的一种特殊状态。强度和作用时间相同的同一应激原,在不同动物引起不同的反应,因为垂体-肾上腺系统机能活动不同。以此为基础,将动物分为应激敏感的和有抵抗力的。农畜中猪最敏感(1976)。在猪,强烈的应激原能引起叫做应激综合征的综合病理症状(1982)。     

17.冷应激动物相关基因表达的研究进展与展望

应激是机体处于不利环境条件下所产生的一系列反应.能够引起应激反应的应激源很多,如冷、热、低血糖、电击等单一的应激源,也可以是水浸束缚、寒冷束缚等复合应激源[1].     

家禽应激综合征

随着烈性传染病得到控制,养殖业方面的经济损失常常是由应激反应所引起的.应激反应在不同品种、年龄、性别的家禽中存在着较大的差异.鸡、鸽比鹅、鸭反应强烈;年龄的应激反应率为幼龄＞大龄＞老龄;性别的应激反应率为:公鸡＞母鸡.据报道,由于温度和光线所致的应激发生率可高达40%～60%,死亡率分别为:鸡23%～31%,鸭14%～24%,鹅14%～21%.当前我国研究较多的是热应激和冷应激.     

鸭应激综合征的防治

应激综合征是指机体在应激源的刺激下,通过垂体-下丘脑系统引起的各种生理和病理演变过程的综合表现。生产实践中,往往容易忽视应激对鸭只的生长发育、生产性能、抗病力和免疫力的影响所造成的经济损失,因此,必须充分认识应激给养鸭业带来的危害性,加强有关预防和减少应激的观念。1临床症状应激源多种多样,由于这些应激源的强弱、持续时间、鸭的品种、年龄以及机体健康和营养状态的不同,     

Comparison of in vitro and in situ methods in evaluation of forage digestibility in ruminants

The objective of this study was to compare the application of different in vitro and in situ methods in empirical and mechanistic predictions of in vivo OM digestibility (OMD) and their associations to near-infrared reflectance spectroscopy spectra for a variety of forages. Apparent in vivo OMD of silages made from alfalfa (n = 2), corn (n = 9), corn stover (n = 2), grass (n = 11), whole crops of wheat and barley (n = 8) and red clover (n = 7), and fresh alfalfa (n = 1), grass hays (n = 5), and wheat straws (n = 5) had previously been determined in sheep. Concentrations of indigestible NDF (iNDF) in all forage samples were determined by a 288-h ruminal in situ incubation. Gas production of isolated forage NDF was measured by in vitro incubations for 72 h. In vitro pepsin-cellulase OM solubility (OMS) of the forages was determined by a 2-step gravimetric digestion method. Samples were also subjected to a 2-step determination of in vitro OMD based on buffered rumen fluid and pepsin. Further, rumen fluid digestible OM was determined from a single 96-h incubation at 38°C. Digestibility of OM from the in situ and the in vitro incubations was calculated according to published empirical equations, which were either forage specific or general (1 equation for all forages) within method. Indigestible NDF was also used in a mechanistic model to predict OMD. Predictions of OMD were evaluated by residual analysis using the GLM procedure in SAS. In vitro OMS in a general prediction equation of OMD did not display a significant forage-type effect on the residuals (observed - predicted OMD; P = 0.10). Predictions of OMD within forage types were consistent between iNDF and the 2-step in vitro method based on rumen fluid. Root mean square error of OMD was least (0.032) when the prediction was based on a general forage equation of OMS. However, regenerating a simple regression for iNDF by omitting alfalfa and wheat straw reduced the root mean square error of OMD to 0.025. Indigestible NDF in a general forage equation predicted OMD without any bias (P ≥ 0.16), and root mean square error of prediction was smallest among all methods when alfalfa and wheat straw samples were excluded. Our study suggests that compared with the in vitro laboratory methods, iNDF used in forage-specific equations will improve overall predictions of forage in vivo OMD. The in vitro and in situ methods performed equally well in calibrations of iNDF or OMD by near-infrared reflectance spectroscopy.     

大庆市羊东毕吸虫病流行病学调查

对大庆市羊东毕吸虫病的流行病学进行了调查研究。结果表明，大庆有3种东毕吸虫，即程氏东毕吸虫（O.cheni)、土耳其斯坦东毕吸虫（O.turkestanica)和土耳斯坦东毕吸虫结节变种（O.turkestanican var.thuberculata)；中间宿主螺类有1种，即卵萝卜螺；东毕吸虫病在大庆分布很广，所调查的4区2县均有发生，羊东毕吸虫平均感染率分别为50．33％，平均死亡率为21．12％，大庆羊急性病例发病时间为8月上旬至10月下旬，慢性病例为11月上旬至翌年2月中旬。     

中国圈养野生动物疫苗使用调查

2005年对中国动物园协会单位中的18家动物园饲养野生动物疫苗免疫情况进行调查。受调查动物园在野生动物疫苗使用和动物种类方面具有一定的代表性。调查结果显示动物园动物现共使用18类36种疫苗,预防31种疫病。其中哺乳动物使用14类24种疫苗,预防24种疫病;禽类使用4类12种疫苗,预防7种疫病。使用范围最广的有禽流感、犬瘟热疫苗等、新城疫疫苗、猫瘟热疫苗等。共有24目58科动物接种疫苗,其中食肉动物类1目8科,食草动物类3目9科,杂食动物类2目3科,禽类18目38科。研究结果提示应加强动物园之间疫病信息交流、防疫资源的利用、疫病监测和研究,加大对动物园动物疫病的研究投入,逐步建立动物园动物统一的防疫规程。     

Estimate of economic impact of fowl cholera in turkeys in Georgia in 1986

Information gathered from cases of fowl cholera (FC) in commercial turkey flocks through case records, flock records, and telephone and mail surveys was used to estimate disease costs. The cost to the Georgia commercial turkey industry in 1986 from preventive measures, treatment of outbreaks, and production losses from the disease was estimated at $634,545. The cost of FC per kg of live production was estimated to be $0.015.     

ELISA试验在防制猪伪狂犬病中的应用

猪伪狂犬病是由伪狂病病毒(Pseudorabies virus PRV)引起的急性传染病。其特征是成年猪常为隐性感染，可有流产、死胎、呼吸系统症状，新生仔猪除神经症状外还可侵害消化系统，并伴大批死亡。本病已经给全世界的养猪业造成严重的损失，我国许多地区已报道该病。为进一步探讨该病的控制、净化措施，我们对12个养猪场共856分血清采用美国嗍公司的ELISA试剂盒进行了抗体检测。     

Use of cyclocryotherapy in management of glaucoma in dogs

In 5 cases of glaucoma (2 from trauma, 2 from narrowed drainage angles, 1 secondary to lens extraction), cyclocryotherapy was used to control intraocular pressure. In all cases the intraocular pressure decreased, with the usual result being a cosmetic and painless but blind eye.     

Occurrence of MRSA in pigs and in humans involved in pig production--preliminary results of a study in the northwest of Germany

In 2007, 678 pigs of all age groups out of 347 different farms from Lower Saxony and Northrhine-Westphalia and 86 persons occupationally exposed to pigs were investigated for their nasal colonisation with methicillin-resistant Staphylococcus areus (MRSA) by the Field Station for Epidemiology of the University of Veterinary Medicine Hannover and the Robert Koch-Institute. At the individual animal level, a frequency of positive results of 13% (n = 85 positive animals) and at the herd level, a frequency of positive results of 18% (n = 62 positive herds) were found. All isolates were assigned to the Multilocus Sequence Typing Type ST398. Within MRSA-positive herds, there were more MRSA-negative than MRSA-positive animals. Among the occupationally exposed persons (veterinarians, laboratory personnel and meat inspection personnel), 20 persons (23%) showed a nasal colonisation with MRSA ST398. A quite strong association between the intensity of the contact to pigs with the frequency of nasal colonisation in the occupationally exposed persons was detected. None of the animals or the humans nasally colonised by MRSA ST398 showed any clinical symptoms of a staphylococcal infection. Conclusions are drawn on the herd and intra-herd prevalence of the nasal colonisation of pigs with MRSA ST398 in pigs, but especially on which questions need to be addressed by further research.     

2017年西藏拉萨市家禽禽流感抗体水平检测

为了解西藏拉萨市家禽禽流感抗体水平,2017年8月随机选择免疫过H5禽流感疫苗的8个规模养殖场、2个散养户、3个活禽交易市场,共13个群体,采集1 041份家禽血清样品进行H5、H7、H9亚型禽流感HI抗体检测。结果显示：H5亚型禽流感免疫抗体合格率为45.73%,H7、H9亚型抗体阳性率分别为21.13%、52.64%;养殖场、散养户和活禽交易市场的不同亚型抗体水平存在较大差异,规模化养殖场的H7亚型抗体阳性率最高（29.92%）,活禽市场的H5、H9亚型阳性率最高（78.16%、79.31%）,散养户的所有亚型抗体阳性率均最低。结果表明,拉萨市H5亚型禽流感疫苗免疫效果较差,特别是散养户,疫病发生风险较高,H7、H9亚型疑似自然感染率较高,应进一步查明原因,及时采取相应的措施,防止疫情发生。