直接式杀菌在降膜式蒸发器中的设计及应用

在奶粉生产中,直接式杀菌与间接式杀菌相比具有杀菌温度稳定且比较均匀、灭菌效果佳、不易产生结垢或结焦、清洗间隔时间较长的优点,不足之处为在杀菌过程中蒸汽直接混入料液中会使料液增湿、杀菌完毕需要将增加部分水分经过闪蒸去除从而对蒸汽质量要求较高。因此,蒸汽必须经过严格过滤或采用单独的蒸汽发生装置方可进入料液中。本文仅以华禹乳品机械制造有限公司生产的RNJM03-8000型三效降膜式蒸发器在奶粉生产中的应用为例,对该设备在奶粉生产中的直接式杀菌设计过程及注意事项进行阐述。     

PLC系统在轧钢生产线自动控制中的应用

在钢铁行业中,不论是冷轧生产线,还是整卷钢板的开卷、剪裁、再卷,这些生产过程都会对操作人员造成伤害。本文将主要探讨如何在轧钢生产线自动控制中采用PLC系统来保证生产的效率和工作人员的安全性。     

磁珠法和柱式法提取核酸在新城疫荧光定量检测中的比较

本试验旨在分析比较磁珠法和柱式法提取病毒核酸的灵敏度及重复性.试验选用实验室常用的磁珠法和柱式法试剂同时提取核酸检测新城疫阳性样品,荧光相对定量比较两种方法的灵敏度及重复性.结果表明,磁珠法提取核酸的检测灵敏度较高,重复性较好,检测成功率较高.表明磁珠法提取核酸在新城疫的荧光定量检测中优于柱式法.     

百净保在种鸡生产中的应用

长期以来,种鸡场的生产过程中大量使用福尔马林(主要成分是甲醛)对种蛋、孵化器以及鸡舍进行熏蒸消毒,虽然能起到好的消毒效果,但是由于甲醛的高危害性,对人员和环境有很大的损害,甚至危害大气中的臭氧层.     

传送带式自动饲喂系统在规模化奶牛场中的应用

降低奶牛养殖投资成本和运营成本对牧场可持续发展具有重要意义,选择适宜的饲喂模式能够提高奶牛养殖效益。本文介绍了3 000头奶牛场传送带式自动饲喂系统的设计,并对该系统和传统TMR饲喂设备在实际应用中降低投资成本和运营成本进行对比和分析。结果显示,传送带式自动饲喂系统可显著降低人工成本、能耗成本和建筑成本,对牧场的智能化发展具有重要意义。     

传染性法氏囊病病毒在不同宿主系统中增殖的比较

传染性法氏囊病(Infectious Bursal Disease,IBD)的病原为传染性法氏囊病病毒(IBDV)，IBDV可在不同宿主系统中增殖。本试验建立了简便、快速的多克隆AC—ELISA方法用于滴定不同宿主系统增殖的IBDV，并与滴定抗原的常规方法作了比较。     

Comparison of different methods used for oestrus examination in the bitch

The aim of this study was to determine the reliability of oestrus symptoms of the bitch (vulvar swelling, vaginal fluid, attraction of the male, teasing) and that of the most frequently used examination methods (vaginal smear, vaginoscopy, serum progesterone determination) which indicate the stage of the cycle and allow to predict the optimal day of mating (ODM). The determination of the cycle stage was based upon the number of days left from the day of examination to the day of parturition (DTP). Our results indicate that none of the above-mentioned symptoms and examination methods is reliable alone for the determination of DTP, and even the complex picture obtained from the integrated results of different methods will not enable an exact estimation. ODM can be predicted with a higher reliability, and 1-2 days before it, it can be detected very safely. Since most bitches are presented for timing to practitioners, a scheme was created based upon a scoring system, which gives a point value to each individual symptom and examination result, and judges the bitch according to the total amount of points.     

用环六亚甲基四胺替代甲醛保存标本

家畜解剖学是动物医学教学、科研的一门主干课程,用甲醛保存标本是目前医学、生物学、兽医学保存标本的基本方法.目前所用的动物标本经固定处理后,为避免水分蒸发、霉烂等变化,常浸泡于甲醛中进行湿保存.甲醛作为一种固定液,具有渗透速度快、固定效果好、作用时间持久等特点,故长期以来一直被人们广泛应用在医学教学和科研工作中.     

不同免疫方法制备IBD卵黄抗体的效果比较

用6种不同的免疫方法接种健康产蛋母鸡所制备的卵黄抗体,用琼扩法测定免疫后不同时期的卵黄抗体效价,并将其作1:4稀释后用于临床治疗试验。结果表明,以第5组(首免肌注自制油乳剂灭活苗2 ml/只,1周后同上法二免)效价最高,总有效率达98％以上,12h后症状即见明显好转。     

几种常见鸽病的防治

经过十几年的发展，肉鸽养殖正逐步从小型分散的饲养方式向集约化、规模化的饲养方式转变。目前，小则三、五千对，多则几万、十几万对的养鸽场正不断出现，养鸽业正向集约化生产规模发展，从而取代分散的、家庭副业式的小规模生产模式，这是养鸽发展的必然趋势，也是养殖业进步的表现，这种集约化的生产模式克     

第十章不同方法控制PRRS病毒的实践经验一大规模养殖系统肉的控制

1引言 PRRS对养猪生产的破坏已超过十年,但养猪生产者和兽医工作人员仍没有就生产系统中的控制方案达成共识.迷惑源于缺乏这两方面的具体信息:PRRS病毒的传播途径和保护免疫力. 尽管在撰写本文时,美国养猪业已经有了三种商用疫苗,但尚无人了解PRRS病毒,野毒株或疫苗株是如何诱导机体产生保护性免疫力的.此外,也没有切实可行的办法可评估弱毒疫苗和异源性PRRS田间毒株间的交叉保护作用.疫苗已在某些生产系统中得到了广泛的应用,但效果不一.某些生产系统报告效果很好,而另一些系统却抱怨疫苗导致了更为严重的疾病.     

常见的几种仔猪腹泻病的防治

夏季天气炎热，是仔猪腹泻病多发的季节，养殖户应注意防治。本文着重介绍几种常见的仔猪腹泻病的病源、症状、病变及综合防治措施，值得借鉴。     

Comparison of several combinations for anesthesia in rabbits.

Few safe and effective anesthesia regimens have been described for use in rabbits, partially because of the susceptibility of this species to sometimes fatal respiratory depression. Although inhalant anesthetics are generally safer than injectable anesthetics, their use may be limited by lack of equipment or facilities. This study was conducted to compare effects of several injectable anesthetics in rabbits on response to noxious stimuli, heart rate, respiratory rate, and rectal temperature. Six injectable anesthetic combinations were administered to rabbits: xylazine-ethyl-(1-methyl-propyl) malonyl-thio-urea salt (EMTU), ketamine-EMTU, xylazine-pentobarbital, xylazine-acepromazine-ketamine (XAK), ketamine-chloral hydrate, and ketamine-xylazine. All combinations induced a depression of respiratory rate. Although rectal temperature values were reduced to some degree in each group, the most profound hypothermia was induced by XAK. The combination that induced the longest duration of anesthesia was XAK. It was concluded that XAK was preferable for longer periods of anesthesia (60 to 120 minutes), although it induces severe hypothermia. For short periods of anesthesia, xylazine-pentobarbital, xylazine-EMTU, or ketamine-xylazine were deemed adequate; however, xylazine-EMTU induced the best survivability and consistency.     

Comparison of several challenge models for studies in avian colibacillosis

In previous studies, the embryo lethality assay (ELA) discriminated between virulent and avirulent avian Escherichia coli isolates, and also proved to be highly correlated with mortality and morbidity results of the intravenous (IV) challenge model. In the current study, the same 20 avian E. coli isolates were used in subcutaneous (subQ) and intratracheal (IT) chicken challenge models in order to determine whether the results from the prior ELA challenges and/or the IV challenge model correlate with these models. The correlation observed between the two previous ELA trials and the combined mortality/morbidity percentages of the subQ challenge model were r = 0.792, P > 0.0001 for the first ELA trial and r = 0.738, P = 0.0002 for the second ELA trial. The IV challenge results were more highly correlated with the subQ challenge results (mortality/morbidity comparison, r = 0.894, P < 0.0001). The IV challenge mortality results were slightly correlated (r = 0.4810, P=0.0319) with the IT challenge results. Several of the isolates differed in their ability to produce mortality and/or morbidity with the different challenge models. The mortality/morbidity results of the IV and subQ challenges and the mortality results of the ELA were all positively correlated with the ability of an E. coli isolate to produce Colicin V (ColV) (r = 0.7131, P = 0.0004). The IT mortality results were slightly correlated with the production of ColV (r = 0.455, P = 0.049). The IT challenge results were only slightly correlated with resulting IV mortality and ColV production. Previous results indicate that the ELA correlates extremely well with the IV challenge model. The current study demonstrates that ELA also correlates well with the subQ challenge model. Overall, the conclusion of this study is that the ELA, IV, and subQ challenge models similarly demonstrate the ability to discriminate between virulent and avirulent avian E. coli isolates.