Biological properties of essential oil emphasized on the feasibility as antibiotic substitute in feedstuff

The discovery and application of antibiotics in animal feeds have boomed the development of intensive animal husbandry in the last century,until the emergence of antibiotics-resistant bacteria.To alleviate the risks aroused by antibiotics-resistant bacteria,effective antibiotic substitutes are urgently needed to replace antibiotics.Essential oils(EOs)derived from plants are illustrated as the promising antibiotic substitutes used in animal feeds,as same as their current views for poultry and livestock industries in the future.It has been widely demonstrated that the phytochemicals in EOs show multiple biofunctionability and are less likely to induce resistance in bacteria.The beneficial effects of EOs feed supplementation on the intestinal inflammation,intestinal flora,immunity,digestion,and growth performances have been already extensively examined.However,the cost-effectiveness,odor,volatility,instability and bioavailability are the challenges in effectively utilizing EOs in animal intestines.Based on previous researches,and these challenges can partially be resolved by microencapsulation and nanotechnology are promising techniques to deal with these challenges.This article presents the feasibility and foundation of EOs application as antibiotic substitutes in animal feeds,and illustrates the mechanisms,functional performances and superiority of EOs compared with antibiotics.

The Mechanism of Resistance of Pseudomonas Aeruginosa toβ-lactam Antibiotics and Clinical Significance

To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ- lactam antibiotics,the outer mem brane permeability rate of30 P.aeruginosa strains to5 β- lactam antibiotics was m easured and their production ofβ- lactamase and theβ- lactam ase genes they carried detected. Furthermore,the relationship between the perm eability,β- lactam ase and the clinical effects ofβ- lactam antibiotics was observed. By using 1 4C- penicillin and liquid- scintillant isotope assay,the affinity of penicillin binding proteins(PBPs) was m easured and their roles in the resistant m echanism studied.Itwas revealed thatthe perm eability rate was higher in sensitive strains than in resistantones(P<0 .0 5 ) .All strains harbored1- 4 β- lactamase genes and produced β- lactam ase.Higher permeability rate and higher degree of stability toβ- lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the perm eability andβ- lactam ase. These results suggested that the permeability of outer mem brane andβ- lacta- mase,but not PBPs,played im portant roles in the resistant mechanism of P. aeruginosa toβ- lac- tam antibiotics and affected the clinical therapeutic effectiveness of som e patients.

分散固相萃取-超高效液相色谱-串联质谱法测定饲料中的多肽类抗生素

试验基于分散固相萃取净化结合超高效液相色谱-串联质谱法,建立一种同时测定饲料中16种多肽类抗生素(PPTs)的定量分析方法。样品经1%三氯乙酸(aq)-甲醇溶液提取,十八烷基硅胶(C18)分散固相萃取净化后上机测定。在电喷雾正电离模式下,使用多反应监测(MRM)模式,基质匹配校正曲线定量。结果显示,PPTs在相应的浓度范围内线性关系良好,相关系数(R2)大于0.99,检出限为0.4~12.1μg/kg,定量限为1.4~40.4μg/kg。PPTs在饲料中的平均回收率(n=6)为80.0%~114.4%,相对标准偏差(RSD)为2.33%~9.51%。研究表明,该方法操作简单、准确可靠、灵敏度高、分析时间短且重现性高,可广泛应用于饲料中16种PPTs的快速筛查和常规监测。

The effect of protective genital care protocol on preventing diaper dermatit development in 0 - 18 month old children using antibiotics

Diaper dermatit is among the widely seen inflamatory skin diseases in neonatals and small 0 - 18 month old children. Control of causative agents as well as providing good genital care may prevent or reduce the risk of the disease. The aim of this study is find out the effect of protective genital care on reducing the diaper dermatit development in 0 - 18 months old inpatient 0 - 18 month old children who are using antibiotic. The study was conducted as prospective half-experimetal using control-experimental groups. Our samples comprise of 0 - 18 month old children admitted at Dokuz Eylul University Practical and Research Hospital, pediatric clinic between January and May 2009, 41 0 - 18 month old children as a control group were not under protective genital care, and 42 0 - 18 month old children as an experimental group were under the protecion and using vaseline. The mothers of the experimental group 0 - 18 month old children were given education. All 0 - 18 month old children were followed-up 3 - 7 days and the collected data were evaluated in computer using Pearson’s chisquare, Fisher’s exact chi-square and Yatest-corrected chi-square tests. The diaper dermatit develop- ment ratio was 34.1% in the control group and 7.1% in the experimental group

Overall assessment of antibiotic substitutes for pigs:a set of meta-analyses

Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in livestock production.We aimed to perform a meta-analysis and network meta-analysis(NMA)to investigate the effects of feed additives as potential antibiotic substitutes(ASs)on bacteriostasis,growth performance,intestinal morphology and immunity.Furthermore,the primary,secondary,and tertiary ASs were defined by comparing their results with the results of antibiotics.Results:Among 16,309 identified studies,37 were summarized to study the bacteriostasis effects of feed additives,and 89 were included in the meta-analysis and NMA(10,228 pigs).We summarized 268 associations of 57 interventions with 32 bacteria.The order of bacteriostasis effects was as follows:antimicrobial peptides(AMPs)≈antibiotics>organic acids>plant extracts>oligosaccharides.We detected associations of 11 feed additives and 11 outcomes.Compared with a basal diet,plant extract,AMPs,probiotics,microelements,organic acids,bacteriophages,lysozyme,zymin,and oligosaccharides significantly improved growth performance(P<0.05);organic acids,probiotics,microelements,lysozyme,and AMPs remarkably increased the villus height:crypt depth ratio(V/C)(P<0.05);and plant extracts,zymin,microelements,probiotics,and organic acids notably improved immunity(P<0.05).The optimal AMP,bacteriophage,lysozyme,microelements,oligosaccharides,organic acids,plants,plant extracts,probiotics,and zymin doses were 0.100%,0.150%,0.012%,0.010%,0.050%,0.750%,0.20%,0.040%,0.180%,and 0.100%,respectively.Compared with antibiotics,all investigated feed additives exhibited no significant difference in effects on growth performance,IgG,and diarrhoea index/rate(P>0.05);AMPs and microelements significantly increased V/C(P<0.05);and zymin significantly improved lymphocyte levels(P<0.05).Furthermore,linear weighting sum models were used to comprehensively estimate the overall impact of each feed additive on pig growth and health.Conclusions:Our findings suggest that AMPs and plant extracts can be used as primary ASs for weaned piglets and growing pigs,respectively.Bacteriophages,zymin,plants,probiotics,oligosaccharides,lysozyme,and microelements can be regarded as secondary ASs.Nucleotides and organic acids can be considered as tertiary ASs.Future studies should further assess the alternative effects of combinational feed additives.

Medium-chain fatty acids and monoglycerides as feed additives for pig production:towards gut health improvement and feed pathogen mitigation

Ongoing challenges in the swine industry,such as reduced access to antibiotics and virus outbreaks(e.g.,porcine epidemic diarrhea virus,African swine fever virus),have prompted calls for innovative feed additives to support pig production.Medium-chain fatty acids(MCFAs)and monoglycerides have emerged as a potential option due to key molecular features and versatile functions,including inhibitory activity against viral and bacterial pathogens.In this review,we summarize recent studies examining the potential of MCFAs and monoglycerides as feed additives to improve pig gut health and to mitigate feed pathogens.The molecular properties and biological functions of MCFAs and monoglycerides are first introduced along with an overview of intervention needs at different stages of pig production.The latest progress in testing MCFAs and monoglycerides as feed additives in pig diets is then presented,and their effects on a wide range of production issues,such as growth performance,pathogenic infections,and gut health,are covered.The utilization of MCFAs and monoglycerides together with other feed additives such as organic acids and probiotics is also described,along with advances in molecular encapsulation and delivery strategies.Finally,we discuss how MCFAs and monoglycerides demonstrate potential for feed pathogen mitigation to curb disease transmission.Looking forward,we envision that MCFAs and monoglycerides may become an important class of feed additives in pig production for gut health improvement and feed pathogen mitigation.

Effect of UV-B radiation on the feeding behavior of the rotifer Brachionus plicatilis

Effect of UV - B radiation on the feeding behaviour of marine zooplankton is important to assessing the health harm of marine ecosystem due to the gradually enhanced UV - B radiation in air. However, there are a few studies on this topic. The feeding behavior of the rotifer, Brachionus plicatilis, under the treatment of UV - B radiation on five species of microalgae, i. e. , Chlorella sp. , Tetraselmis chuii, Isochrysis galbana Park 8701, Chaetoceros muelleri Lermumerman, and Nitzschia clostertum, was studied. The results showed that the filtering and feeding rates of the rotifer decreased significantly with the dose increase of UV - B radiation when fed with five species of microalgae respectively （ P 〈 0.05 ） which indicates UV - B radiation inhibits the feeding activities of the rotifer on microalage. The mixed culture experiments shows the rotifer preferred to feed Chlorella sp. , then C. muelleri, L galbana, N. clostertum and T. chuii in turn if without UV - B radiation. Under the highest dose of UV - B radiation treatment （2.70 kJ/m^2）, the rotifer preferred to feed C. muelleri, then Chlorella sp. , N. clostertum, L galbana and T. chuii in turn. Chlorella sp. , L galbana and C. muelleri became the more favorite foods of the rotifer while T. chuii and N. clostertum became less favorite foods. The change of feeding rate and feeding selectivity of zooplankton driven by the enhanced UV - B radiation will lead to the change in the structure of phytoplankton community.

高效液相色谱-串联质谱法测定配合饲料中土霉素、四环素、金霉素、多西环素的不确定度评估

试验旨在采用高效液相色谱-串联质谱法测定配合饲料中土霉素、四环素、金霉素、多西环素的含量,并进行不确定度的来源分析和评定。根据农业农村部第282号公告《饲料中土霉素、四环素、金霉素、多西环素的测定》,通过对样品称量、样品提取、标准溶液配制、仪器检测及标准曲线建立等主要因素进行考察,并建立数学模型,计算不同因素对药物检测时不确定度的影响。结果表明:标准溶液配制、标准曲线建立对检测不确定度的贡献较大,而样品称量对不确定度的影响较小,进一步得出合成不确定度和扩展不确定度。配合饲料中土霉素、四环素、金霉素、多西环素检测值分别为51.98、52.35、52.95、51.93μg·kg^(-1)时,其扩展不确定度分别为9.66、6.78、8.88、8.91μg·kg^(-1)(P=95%, k=2)。

Investigation on the Structure of Chute-feed and Card Auto-leveller and Their Selection of Technological Processes

Based on the structure of chute - feed and autoleveHer, an analysis of their working principle and the verification of their practical production results have been carried out. Finally, the future investigation direetiom of chute - feed and card autuleveller are put forward.

饲料添加中药抗病促生长与替抗应用研究

重点回顾兽用中药抗病促生长的历史背景,对兽用中药饲料添加应用经验进行总结,提出兽用中药“替抗”应以饲料添加为主要应用方向。对农业农村部饲料药物添加剂品种、《饲料原料目录》、卫生部门发布的“食药物质”目录进行全面梳理,提出“药饲同源”品种名单,研究提出科学遴选和应用兽用中药“替抗”品种原则建议,在现有兽药国家标准和注册标准品种基础上,通过与“药饲同源”品种比对分析,筛选出21种“替抗”兽用中药制剂,为兽用抗菌药使用减量化提供参考。

发酵玉米-豆粕型全价饲料对生长猪生长性能、粪便臭味物质和菌群区系的影响

旨在研究发酵全价饲料对生长猪生长性能、粪便臭味物质和肠道菌群的影响,评价发酵全价饲料在生长猪上的应用效果。试验以乳酸菌和地衣芽孢杆菌为发酵菌剂,对全价饲料进行3d厌氧发酵,制备发酵全价饲料。选取体重22kg左右的生长猪90头,随机分成3组,每组30头猪,分别饲喂无抗饲料、含抗生素饲料和发酵饲料,体重达到40kg左右时,测定各试验组动物的生长性能;采集新鲜粪便样品,采用气相色谱法测定粪便中挥发性臭味物质的含量;利用16S高通量测序技术,分析粪便菌群区系变化。结果显示:1)全价饲料经发酵后,粗脂肪含量显著升高(P<0.01),钙(P<0.01)和总磷(P<0.05)含量显著降低,pH显著降低(P<0.01),乳酸菌数量达到9.67lg cfu·g^(-1),乳酸含量达到421.67mmol·kg^(-1)。2)动物试验结果表明,与对照组相比,饲喂发酵饲料显著提高了生长猪的ADFI和ADG(P<0.05),降低了F/G和死淘率(P<0.05);与抗生素组相比,发酵饲料显著提高了生长猪的ADFI(P<0.05)。3)饲喂发酵饲料组的猪粪便中吲哚含量显著降低(P<0.05),粪臭素和挥发性脂肪酸(VFA)含量降低,甲酚含量升高。4)发酵饲料还提高了生长猪粪便菌群的丰度和和多样性,其中门Tenericutes、Saccharibacteria,属Clostridium、Turicibacter、Mollicutes、Anaerostipes、Acetitomaculum的相对丰度升高;属Lactobacillus、Streptococcus、Rikenellaceae、Megasphaera、Oscillospira、Mitsuokella、Prevotella的相对丰度降低。综上,发酵全价饲料提高了生长猪的生长性能,降低了粪便中吲哚、粪臭素以及挥发性脂肪酸的含量,提高了粪便中对甲酚的含量,改变了粪便微生物区系。

超高效液相色谱-电喷雾串联质谱法测定动物饲料中的大环内酯类和林可胺类抗生素

建立了动物饲料中竹桃霉素、红霉素、吉他霉素、交沙霉素、罗红霉素、泰乐菌素6种大环内酯和林可霉素、克林霉素2种林可胺抗生素的超高效液相色谱-电喷雾串联质谱(UPLC-ESI-MS/MS)检测方法。饲料样品采用甲醇提取,OasisHLB固相萃取柱富集净化,WatersAcquityUPLCBEHC18色谱柱分离,以0.1%甲酸和乙腈为流动相进行梯度洗脱,流速为0.3mL/min,正离子模式扫描,多反应监测模式检测,外标法定量。实验结果表明,8种药物在1～100μg/L范围内具有良好的线性关系。在空白饲料样品中分别添加1、10和100μg/kg3个加标水平的8种药物,其平均回收率为68.6%～95.2%,相对标准偏差(RSD)为4.9%～11.8%,定量限均为1μg/kg。结果表明,该方法简便快速、灵敏度高,适用于动物饲料中大环内酯类和林可胺类抗生素的同时检测。

固相萃取-GC-MS法测定饲料中的沙丁胺醇

沙丁胺醇(salbutamol),化学名称1-(4-羟基-3-羟甲基苯基)-2-(叔丁氨基)乙醇(结构式如图1所示),俗称舒喘宁,属于β-兴奋剂类药物的一种,临床上用于治疗支气管哮喘.同时沙丁胺醇同克伦特罗(瘦肉精)一样还具有提高饲料的转化率,促进动物生长的作用.但是,这种药物容易在动物内脏、组织中蓄积残留,有很大的副作用.……

固相萃取净化/高效液相色谱-串联质谱法测定饲料中7种大环内酯类药物含量

建立了添加剂预混合饲料、精料补充饲料、配合饲料和浓缩饲料中7种大环内酯类药物(替米考星、罗红霉素、螺旋霉素、泰乐菌素、红霉素、克拉霉素和阿奇霉素)含量的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。饲料样品经1%氨化乙腈提取,Oasis PRiME HLB固相萃取柱净化后,采用ACQUITY UPLC BEH C18色谱柱(2.1 mm×100 mm,1.7μm)分离,以0.1%甲酸水-乙腈为流动相梯度洗脱,电喷雾离子源正离子模式下检测,外标法定量。结果表明,替米考星、螺旋霉素和红霉素的线性范围为0.5~50μg/L(r2>0.99),罗红霉素、泰乐菌素、克拉霉素和阿奇霉素的线性范围为0.25~50μg/L(r2>0.99);7种待测物的检出限(LOD)为1.25~2.5μg/kg,定量下限为2.5~5.0μg/kg,5、10、50μg/kg 3个加标浓度下的平均回收率为61.4%~103%,批内和批间相对标准偏差为0.43%~15%。该方法简便、快速、灵敏,基质干扰小,适用于各类饲料中大环内酯类药物的常规监测和定量测定。

土壤细菌YR-07溶菌酶饲喂仔猪效果的研究

[目的]为了开发绿色、天然的饲料添加剂,从而取代抗生素。[方法]将土壤细菌YR-07溶菌酶和不同种类的抗生素分别加入到饲料中,对不同品种肉猪进行对比饲养试验。[结果]结果表明,添加YR-07溶菌酶的饲料在促进仔猪日增重、提高饲料转化率和改善饲养经济效益方面均优于目前常用的添加抗生素的猪饲料。[结论]该研究为土壤细菌YR-07溶菌酶的推广应用提供了依据,同时对促进饲料工业发展和提高人类健康水平具有重要意义。

超高效液相色谱-静电场轨道离子阱高分辨质谱联用筛查分析饲料中抗菌类药物

将73种抗菌药物标准品混合物经超高效液相色谱－静电场轨道离子阱高分辨质谱（UPLC-Orbitrap HRMS）分离和离子化，确定抗菌药物的离子化模式，建立抗菌药物实测精确分子量和保留时间标准数据库．饲料样品匀质后采用50％（v／v）乙腈水溶液一次提取和乙腈二次提取，经氨基固相萃取小柱净化，氮气吹干浓缩、过滤等处理后进行检测．结果表明，本法在测定饲料中抗菌药物时，回收率34．51％～129．64％，相对标准偏差0．1％～24．4％；在添加量为5μg·g －1时，均可检出．

具有益生功能芽孢杆菌的筛选鉴定及特性研究

本研究旨在筛选出产酶能力及抑菌性能优良的发酵菌株,为新型饲料资源的开发和抗生素替代品的研究提供参考。以蜡样芽胞杆菌菌株H14为出发菌株,分析其酶学特性和抑菌性能,通过单因素试验对发酵菜籽粕的饲料添加量与发酵时间进行优化。筛选鉴定出一株产纤维素酶、蛋白酶、淀粉酶、木聚糖酶的蜡样芽胞杆菌H14。产纤维素酶最适反应条件为60℃,pH 9,酶活11.51 U/mL,蛋白酶酶活73.68 U/mL,淀粉酶酶活5.96 U/mL,木聚糖酶酶活14.02 U/mL。对大肠杆菌和金黄色葡萄球菌最大抑菌直径分别为18.200±0.200 mm和17.567±0.493 mm。发酵菜籽粕产纤维素酶的最佳条件为菜籽粕添加量25%,发酵48 h,酶活为12.608 U/mL,对大肠杆菌和金黄色葡萄球菌的最佳抑菌效果分别为菜籽粕添加量25%,发酵48 h,抑菌直径为24.933±0.204 mm;菜籽粕添加量25%,发酵72 h,抑菌直径为27.400±0.529 mm,发酵产物含蔗糖、木糖、葡萄糖。综上所述,本研究成功筛选出一株具有良好产酶和抑菌特性的发酵菌株H14,其在发酵菜籽粕生产中表现出良好的应用潜力,为未来发酵饲料的研发提供了有价值的参考。

酸化剂-乳酸在饲料添加剂中的应用

乳酸是重要的生物化工产品,其生化特性在饲料行业发挥着作用,逐渐取代饲用抗生素,可促使有益菌的生长、调节细胞功能、增强动物的生长发育,是其它有机酸不能相比的。

生物饲料在动物养殖中的应用研究进展

在畜禽饲料端“禁抗”的背景下,生物饲料作为抗生素替代产品备受关注。生物饲料具有改善饲料品质以及提高动物生产性能、提升动物免疫力、调节动物肠道菌群等功能,市场接受度日益提高。介绍了生物饲料的定义和分类,以发酵饲料和菌酶协同发酵饲料为例,综述生物饲料在牛、羊、猪生产中的应用研究进展,分析当前生物饲料应用存在的问题并提出相关建议,以期为生物饲料的开发及应用提供参考。

Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production

Naturally occurring plant compounds including tannins, saponins and essential oils are extensively assessed as natural alternatives to in-feed antibiotics.Tannins are a group of polyphenolic compounds that are widely present in plant region and possess various biological activities including antimicrobial,anti-parasitic, anti-viral, antioxidant, anti-inflammatory, immunomodulation, etc.Therefore, tannins are the major research subject in developing natural alternative to in-feed antibiotics.Strong protein affinity is the well-recognized property of plant tannins, which has successfully been applied to ruminant nutrition to decrease protein degradation in the rumen, and thereby improve protein utilization and animal production efficiency.Incorporations of tannin-containing forage in ruminant diets to control animal pasture bloat, intestinal parasite and pathogenic bacteria load are another 3 important applications of tannins in ruminant animals.Tannins have traditionally been regarded as "anti-nutritional factor" for monogastric animals and poultry, but recent researches have revealed some of them, when applied in appropriate manner, improved intestinal microbial ecosystem, enhanced gut health and hence increased productive performance.The applicability of plant tannins as an alternative to in-feed antibiotics depends on many factors that contribute to the great variability in their observed efficacies.