Efficacy of chlorine dioxide gas in reducing Escherichia coli and Salmonella from broiler house environments

Escherichia coli and Salmonella spp. are considered to be the major pathogens associated with human transmissible infectious diseases in the air of poultry houses. Chlorine dioxide (ClO₂) is an effective biocide against a wide range of microorganisms. Accordingly, this study investigated the efficiency of gaseous ClO₂ application for disinfecting broiler houses by collecting air samples before and after fumigation using a passive method. Fumigation was performed with 125 mL or 250 mL of ClO₂ liquid (containing 2,000 ppm of ClO₂) and 3 trials were conducted for each dose. A total of 27 petri dishes were used for each trial (for each type of bacteria: E. coli or Salmonella) and placed in 3 different locations (front, middle and back) and 3 different positions (top, middle and floor) of the broiler shed. Air samples were collected at 10 min, 1 h, 3 h, 6 h, and 12 h before and after fumigation to evaluate the air quality in terms of the concentration of E. coli and Salmonella. Both levels of ClO₂ were capable of reducing the concentration of E. coli from broiler house air during all measuring periods except 10 min, with highest disinfection rate being observed at 6 h. With the exception of 1 h, the concentration of Salmonella was also reduced after fumigation with ClO₂ in all measuring period; with the highest disinfection rate occurring at 6 h. Fumigation with ClO₂ had no negative effect on birds’ health condition. Taken together, these results suggest that the application of gaseous ClO₂ at the investigated levels can be an effective option for reducing bacterial load from broiler house environments.     

二氧化氯在猪场的应用及前景

非洲猪瘟疫情暴发之后,猪场很重视消毒工作。但是如何正确选择和使用消毒药,还存在一些误区。二氧化氯作为第四代杀菌消毒剂,目前在猪场还没有得到广泛的使用,文旨在介绍二氧化氯的特性,杀菌机理,以及在猪场如何正确的使用二氧化氯,从而达到高效,安全,有效消毒的目的,简述二氧化氯在猪场的应用前景。     

Influence of chlorine,iodine, and citrate-based water sanitizers on the oral bioavailability of enrofloxacin in broiler chickens

This experiment was conducted to determine if the 3 most commonly used water sanitizers in commercial broiler chicken production affected the stability of enrofloxacin (ENR), when each was administered concurrently with ENR to broiler chickens via the drinking water. To that effect, the in vitro antibacterial activity of the solution of each ENR-sanitizer product (ESP) was compared to that of ENR alone. Also, bioavailability (F) studies of ESP were carried out in chickens and compared to the corresponding values of ENR in drinking water without sanitizer. Water sanitizers tested were iodine (as iodine-polyvinylpyrrolidone), chlorine (as sodium hypochlorite), and a citrate-based sanitizer from grapefruit extract. They were mixed with ENR in sterile de-ionized water, and the resulting substances were regarded as ESP. Then, the referred studies of ESP were carried out. Results showed that ESP of ENR/sodium hypochlorite decreased both the antimicrobial activity, as well as maximum serum concentration (C_max) and F of ENR in chickens. ESP of ENR/citrate-based sanitizer increased both the in vitro antimicrobial activity and C_max and F values of ENR at the 2 highest concentrations tested. ESP of ENR/iodine reduced both in vitro antimicrobial activity and C_max values of ENR at the highest concentrations tested. This study demonstrated that interactions between water sanitizers and ENR must be considered when medicating chickens via the drinking water to meet pharmacokinetics/pharmacodynamics ratios. The use of a citrate-based sanitizer is recommended, as relative F was increased.     

On-line brush and spray washers to lower numbers of Campylobacter and Escherichia coli and presence of Salmonella on broiler carcasses during processing

It is unclear how effective different types of broiler carcass wash steps are in lowering the presence or numbers of pathogenic bacteria. We tested for individual and combined effectiveness of 5 separate on-line wash steps applied between bleed-out and chilling in a commercial broiler processing plant. Carcasses were sampled directly before and after each wash step: pre-scald brush washer, post-feather pick (New York dressed) spray washer, inside/outside spray washer, postevisceration brush washer, and final prechill spray washer. Carcasses were examined for numbers of Campylobacter and Escherichia coli and presence of Salmonella using standard cultural methods. Overall, numbers of Campylobacter were lowered from log 2.58 to 1.15 cfu/mL of carcass rinse, but no single wash step caused a significant decrease. Overall, Salmonella prevalence was decreased from 80 to 24%; however, no wash step caused a significant decrease by itself. The 5 wash steps in series lowered E. coli numbers from log 4.60 to 2.69 cfu/mL; the New York-dressed spray wash and the postevisceration brush washer each had a significant effect on E. coli. When examined separately, the benefit of broiler carcass wash steps may not be evident. However, when combined with overall processing, wash steps can be effective to lessen bacterial contamination on carcasses and be useful for pathogen control. Additional studies are necessary to maximize the effectiveness of carcass washers.     

木聚糖酶在肉仔鸡日粮中的应用

本文就木聚糖酶的来源、理化性质及其在肉仔鸡生产中的应用作一综述。     

酵素在肉鸡养殖中的应用研究

酵素又称农用酶,是酵素菌在维持生命活动过程中分泌的一些酶和活性物质。近年来,兴起了大量关于酵素的研究,在畜禽生产中,饲喂酵素可提高饲料的消化率,降低畜禽消化系统疾病发病率,增强畜禽免疫力,催化分解饲料,提高饲料转化率和利用率,改善肉质,提高产量等,同时,饲喂酵素还可减少畜禽体内兽药残留量,减轻畜禽粪便臭味等。研究将贵州山区常见药用植物:艾叶、鱼腥草、千里光、青蒿,分别制作单品酵素及复合酵素,按照5%的比例与水混匀后给肉鸡直接饮用103天,肉鸡重量和成活率明显提高,肉质更优。同时,由于鸡舍内刺鼻气体明显减少,呼吸道疾病发病率随之降低,有效提高了肉鸡生产性能,为早期肉鸡养殖中减少或不使用抗生素,减少兽药残留提供了参考。     

金银花在肉鸡饲料中的应用效果研究

采用对比试验,将60只7日龄哈巴特肉鸡随机分为2组（对照组和试验组）,每组10个重复,每个重复3只,饲养在不锈铜笼中。对照组和试验组分别饲基础喂日粮、添加0．3％金银花基础日粮,结果表明,试验期间试验组与对照组鸡的日采食量、日增重、饲料转化率、周末体重差异不显著（P〉0．05）。添加0．3％金银花在7—21日龄与21-42日龄时,肉鸡的日增重分别比对照组提高3．98％和1．33％;胸腺、法氏囊、脾脏脏器指数分别比对照组提高6．94％、4．93％、2．86％,差异不显著（P〉0．05）.     

几种绿色饲料添加剂在肉鸡生产上的应用效果

选1日龄AA肉鸡390只,分成13组,分别添加不同种类和不同种类组合的绿色饲料添加剂。试验结果表明,益生素能显著(p<0.05)提高肉鸡的生产性能,改善肉品质。     

蛋鸡在快速黄鸡配套中的应用研究（续）

2 商品肉鸡观察试验 2.1 试验材料与方法 2.1.1 素材来源 TR—83商品代种蛋为我所一室提供,红宝商品代及红宝AB种蛋引自江苏农垦第一种鸡场,B系为我所利用TR—83祖代B系漏检公鸡扩繁育成,HD、YD是本研究的父母代母本组合。     

中草药添加剂在肉仔鸡生产中的应用

中草药添加剂是以传统中兽医“医食同源”理论和动物生理需要为主导,借助现代化饲料生产加工理论技术制成的绿色环保型添加剂。合理使用中草药添加剂能够促进动物生长发育﹑调节免疫系统和新陈代谢﹑保障动物健康。本文拟在综述中草药添加剂的生理功能及在肉仔鸡生产中的作用,分析其在生产应用中的缺陷,为其在肉仔鸡生产中的应用提供参考。