二硫代碳酸香芹酚酯对人工诱发鸡球虫病的疗效实验

为了评价二硫代碳酸香芹酚酯的抗球虫效果,将其按100、150、200mg/kg浓度添加于饲料中治疗人工感染鸡柔嫩艾美耳球虫病,设妥曲珠利25mg/kg、地克珠利2mg/kg浓度拌料给药作对照。结果显示,二硫代碳酸香芹酚酯高、中两种剂量治疗鸡球虫病具有良好的效果,抗球虫指数均在160以上,与妥曲珠利的效果相当,属于中效抗球虫药。临床推荐150mg/kg拌料给药,连用7d。     

凹凸棒石复合物对肉仔鸡生产性能、免疫机能和抗氧化机能的影响

本试验旨在研究香芹酚/凹凸棒石(CAR/APT)和香芹酚/氧化锌/凹凸棒石(CAR/ZnO/APT)替代抗生素类促生长剂对肉仔鸡生产性能、免疫机能和抗氧化机能的影响。选取1日龄罗斯308肉鸡192只,随机分成3组,每组8个重复,每重复8只,分别饲喂基础饲粮中添加100mg/kg土霉素钙(OTC)、0.1%CAR/APT和0.1%CAR/ZnO/APT的饲粮,基础饲粮不含抗生素类促生长剂。结果表明:与OTC组相比,CAR/APT和CAR/ZnO/APT对肉鸡1~21日龄生产性能无显著影响(P>0.05)。与OTC组21日龄肉鸡相比,CAR/ZnO/APT对胸腺和脾脏器官指数无显著影响(P>0.05),显著降低法氏囊器官指数(P<0.05);CAR/APT对法氏囊指数无显著影响(P>0.05),显著降低胸腺和脾脏器官指数(P<0.05)。与OTC组21日龄肉鸡相比,CAR/ZnO/APT显著提高血清IgG含量(P<0.05),CAR/APT对血清免疫球蛋白含量无显著性影响(P>0.05)。与OTC组21日龄肉鸡相比,CAR/ZnO/APT有提高空肠黏膜sIgA和IgG含量的趋势(P=0.055);CAR/ZnO/APT组空肠黏膜IgM含量显著高于CAR/APT组(P<0.05)。与OTC组21日龄肉鸡相比,CAR/ZnO/APT显著提高血清和空肠黏膜中T-AOC及血清CAT活性(P<0.05);CAR/APT显著提高血清CAT活性和空肠黏膜T-AOC(P<0.05);CAR/ZnO/APT组21日龄肉鸡血清和空肠黏膜T-AOC显著高于CAR/APT组(P<0.05)。结果表明,以0.1%CAR/APT或CAR/ZnO/APT替代饲粮中的OTC,对肉仔鸡生产性能无显著影响,具有提高免疫机能和抗氧化机能的作用,其中CAR/ZnO/APT效果更优。     

高效液相色谱法测定饲料香味剂中香芹酚和百里香酚含量的研究

本实验建立了高效液相色谱法测定饲料香味剂中香芹酚和百里香酚的方法。试样经甲醇提取后,用HPLC测定香芹酚和百里香酚。结果表明:香芹酚和百里香酚的线性范围为1.0～500.0μg/mL,回收率分别为96.8%～99.2%和97.6%～101.4%,变异系数分别为1.0%和1.6%;方法定量限为50mg/kg。本方法对饲料香味剂中香芹酚和百里香酚的检测分析准确性高、重现性好。     

饲料添加剂牛至油中香芹酚和百里香酚含量的测定

试验建立了高效液相色谱法测定饲料添加剂牛至油中香芹酚和百里香酚含量的方法。采用高效液相色谱法,色谱柱Diamonsil C18(2)柱,流动相为甲醇-水-冰醋酸(60??4??2),检测波长274 nm,流速1.0 ml/min。结果显示,牛至油中香芹酚含量为37.81%,百里香酚含量为7.05%,香芹酚和百里香酚的回收率分别为98.2%、98.4%,变异系数分别为1.0%、1.3%。试验为牛至油中香芹酚和百里香酚的检测提供了准确、灵敏、可靠的分析方法。     

Sub-lethal levels of carvacrol reduce Salmonella Typhimurium motility and invasion of porcine epithelial cells

The European ban on the use of antibiotic growth promotors has increased the search for new alternatives to prevent pig intestinal microbial diseases and to stimulate growth. The addition of essential oils or components thereof, such as carvacrol, to pig feed is a promising alternative. In this report we determined the effect of sub-lethal concentrations of carvacrol on Salmonella Typhimurium. At concentrations where growth of Salmonella was not inhibited, carvacrol completely inhibited motility of the bacterium. This loss of motility was not due to the loss of the flagellum or to ATP shortage upon carvacrol treatment. Adhesion of Salmonella to IPEC-J2, porcine intestinal epithelial cells, was not affected by carvacrol but invasion was significantly reduced. In addition, the epithelial gene expression of porcine β-defensin 2, an innate immune response to Salmonella infection, was reduced when Salmonella was exposed to carvacrol. This indicates that invasion but not adhesion of Salmonella triggers the porcine β-defensin 2 expression of porcine epithelial cells.     

Effects of oral administration of different dosages of carvacrol essential oils on intestinal barrier function in broilers

Essential oils are widely used in the pharmaceutical, food and cosmetic industries, and many plant essential oils have shown that they have positive effects on broilers nutrition. This experiment was conducted to study the effects of orally administered different dosages of carvacrol essential oils on intestinal barrier function in broiler chickens. A total of eighty 28‐day‐old (1.28 ± 0.15 kg) ROSS 308 broilers were randomly allocated to four groups of 20 replicates each, with one chicken per replicate per cage, and all were fed with the same diet. Four experimental groups were orally administered 0, 200, 300 or 400 μl carvacrol essential oils at 18:00 hr every day during the 2‐week experimental period. As a result of which, the gene expression of the occludin, claudin‐1, claudin‐5, ZO‐1 and ZO‐2 in intestinal mucosa of small intestine (p < 0.05) and the goblet cell content in small intestine epithelium (p < 0.05) were significantly increased; test subjects with 300 or 400 μl carvacrol essential oils reduced the microbial counts of Salmonella spp. and Escherichia coli in the intestines (p < 0.05); Essential oils administration also significantly increased activity of the sucrase (p < 0.05) and lactase (p < 0.05) in intestinal mucosa. In conclusion, the carvacrol essential oils have positive effects on growth performance and intestinal barriers function of broilers; those effects may be related to the dosage, as administration of 300 or 400 μl was more effective than that of 200 μl.     

In vitro antibacterial activity of thymol and carvacrol and their effects on broiler chickens challenged with Clostridium perfringens

Background:In the post-antibiotic era,essential oils(EO) are promising alternatives to growth-promoting antibiotics.The aim of the present study was to investigate the antibacterial activities of an EO product and its components thymol and carvacrol in vitro,and the efficacy of EO to control Clostridium perfringens challenge in broiler chickens.Results:The in vitro minimum inhibitory concentration assay showed strong antibacterial activity of the EO product,thymol,and carvacrol against pathogenic Escherichia coli,C.perfringens,and Salmonella strains,and weak activity towards beneficial Lactobacillus strains.Besides,an additive effect was observed between thymol and carvacrol.The in vivo study was carried out with 448 male broiler chicks following a 4 × 2 factorial arrangement to test the effects of EO supplementation(0,60,120,or 240 mg/kg EO in wheat-based diet),pathogen challenge(with or without oral gavage of C perfringens from day 14 to day 20) and their interactions.Each treatment consisted of eight replicate pens(seven birds/pen).The challenge led to macroscopic gut lesions,and resulted in a significant increase in ileal populations of C.perfringens and Escherichia subgroup(P 0.05) on day 21.Dietary EO supplementation did not influence C perfringens numbers,but linearly alleviated intestinal lesions on day 21 and 28(P=0.010 and 0.036,respectively),and decreased Escherichia populations in ileum with increased EO dosages(P=0.027 and 0.071 for day 21 and 28,respectively).For caecum,EO quadratically influenced Lactobacillus populations on day 21(p=0.002),and linearly decreased the numbers of total bacteria and Escherichia on day 28(P=0.026 and 0.060,respectively).Mean thymol and carvacrol concentrations in the small intestine were 0.21 and 0.20 μg/g in intestinal digesta(wet weight),respectively,for birds fed 60 mg/kg EO,and 0.80 and 0.71 μg/g,respectively,for birds fed 240 mg/kg EO.Conclusions:These results indicated that dietary EO supplementation could affect intestinal microbiota and alleviate intestinal lesions in broilers,which may contribute in controlling C.perfringens infection in broiler chickens.     

Effects of thymol and carvacrol supplementation on intestinal integrity and immune responses of broiler chickens challenged with Clostridium perfringens

Background: Necrotic enteritis caused by Clostridium perfringens infection leads to serious economic losses in the global poultry production. In the present study, we investigated the protective effects of essential oils(EO, which contained 25 % thymol and 25 % carvacrol as active components) supplementation on growth performance, gut lesions, intestinal morphology, and immune responses of the broiler chickens infected with C. perfringens. A total of448 1-day-old male broiler chicks were allocated into eight treatment groups following a 4 × 2 factorial arrangement with four dietary EO dosages(0, 60, 120, or 240 mg/kg) and two infection status(with or without C. perfringens challenge from d 14 to 20).Results: The challenge did not impair the growth performance of birds, but induced gut lesions and increased crypt depth in the ileum(P ≤ 0.05). It also down-regulated the claudin-1 and occludin m RNA expression(P ≤ 0.05),up-regulated the m RNA expression of interleukin-1β(P ≤ 0.05), tended to increase the toll-like receptor(TLR)2 m RNA expression(P 0.10) in the ileum, and enhanced the mucosal secretory Ig A production(P ≤ 0.05). In the challenged birds, dietary EO supplementation linearly alleviated the gut lesions and improved the ratio of vil us height to crypt depth(P ≤ 0.05), and the supplementation of 120 and 240 mg/kg EO increased the serum antibody titers against Newcastle disease virus(P ≤ 0.05). Regardless of challenge, the EO supplementation showed a tendency to linearly elevate the feed conversion efficiency between 14 and 28 d of age as well as the occludin m RNA expression(P 0.10), and linearly inhibited the m RNA expression of TLR2 and tumor necrotic factor-α in the ileum(P ≤ 0.05).Conclusions: The dietary supplementation of EO could alleviate the intestinal injury by improving intestinal integrity and modulating immune responses in the C. perfringens-challenged broiler chickens.     

Effects of carboxy methyl cellulose and thymol + carvacrol on performance,digesta viscosity and some blood metabolites of broilers

This study was conducted to evaluate the effects of thymol + carvacrol as plant essential oils on performance, digesta viscosity and some blood metabolites of broilers fed diets supplemented with carboxy methyl cellulose (CMC) and/or thymol+carvacrol. In a completely randomized design with a 2 × 3 factorial arrangement, two levels of CMC (0% and 2%) and three levels of thymol+carvacrol (0, 100 and 200 mg/kg) were used. Each of the six dietary treatments was fed to five replicate pens of 12 birds each from 0 to 42 days of age. Body weight gain (BWG), feed intake, feed conversion ratio (FCR), intestinal digesta viscosity and pH, plasma lipids and some blood metabolites were recorded. The inclusion of 2% CMC decreased (p < 0.05) BWG by 2.2% and increased FCR by 2.3% at 42 days of age. Carboxy methyl cellulose significantly increased the digesta viscosity and decreased serum total cholesterol, but had no significant effect on triglyceride, pH, HDL, LDL and other blood metabolites measured in this experiment. Thymol+carvacrol had no effect on feed intake, but significantly increased (p < 0.05) BWG from 1 to 42 days of age and improved FCR (p < 0.05) by the addition of 100 and 200 mg/kg thymol+carvacrol respectively. Inclusion of thymol+carvacrol at levels of 100 and 200 mg/kg in the diets decreased digesta viscosity and serum total cholesterol (p < 0.05) and also increased AST at a 200 mg/kg thymol+carvacrol without any effect on creatine kinase (CK). Thymol+carvacrol significantly increased total protein (TP), albumin and globulin (p < 0.05). In conclusion, CMC at an inclusion level of 2% of diet increased digesta viscosity and reduced growth performance. However, thymol+carvacrol decreased digesta viscosity and consequently improved the performance of broilers fed the CMC‐based diet. Therefore, thymol+carvacrol addition to viscose‐based diets might be helpful to alleviate the negative effects of viscous compounds in poultry diets.     

VC-2-三聚磷酸酯热稳定性的研究

实验分别在80、90、100、110、120℃和0.05、0.1、0.15MPa大气压下,通过紫外吸收法研究了VC-2-三聚磷酸酯的热稳定性。实验结果表明,VC-2-三聚磷酸酯的热稳定性随着温度的升高而降低,随着压强的升高而降低;同时在温度和压强不变的条件下随着时间的延长而降低,但保留率保持在90%以上。     

高效液相色谱法检测阿司匹林丁香酚酯含量

为了评价阿司匹林丁香酚酯的纯度,用高效液相色谱法对阿司匹林丁香酚酯的含量测定进行了方法学研究。试验采用Agilent Technologies 1290高效液相色谱仪,Hypersil ODS色谱柱,乙腈-水(65∶35)为流动相,流速1 mL/min,柱温35℃,检测波长为279 nm。结果:该方法测定阿司匹林丁香酚酯含量系统适应性好,检测限为0.2μg/mL,定量限为0.7μg/mL;线性关系良好,线性回归方程为:y=8.930x-7.450,R~2=0.999 0;平均回收率为100.07%;重复性良好,RSD为0.72%;系统耐用性中各水平下的峰面积、理论塔板数和分离度均符合标准;测定3批样品含量分别为98.4%、99.3%和99.8%。研究表明本方法专属性好,线性关系符合规定,准确度,重复性测定结果在规定范围内,系统耐用性好,3批样品含量符合标准。     

新型防霉剂富马酸酯类

1新型防霉剂的优点长期以来,广泛应用的化学防霉防腐剂主要是有机酸及其盐类,如苯甲酸及其钠盐,山梨酸及其钠、钾盐,丙酸及其钠、钙盐,脱氢醋酸及其钾盐等。它们都对细菌和霉菌有很强的抑制作用,但其毒性都较高,有些品种如苯甲酸钠、脱氢醋酸钠等被世界卫生组织禁止使用;即使使用,其使用条件和使用范围也受到很大限制。20世纪80年代以后,新开发的有机酸酯作为防霉防腐剂已被广泛采用,原因主要有以下几大特点:1)毒性较低,使用安全。有机酸酯类与有机酸盐作为防霉防腐剂的毒性比较,见表1。2)杀菌力极强,且具有广谱性,对霉菌有特殊抑制效果,特…     

炎消热清的镇痛作用及其机理研究

为了研究炎消热清(AEE)的镇痛作用及其可能的机制,采用热板法和扭体法考察AEE的镇痛效果,并观察热刺激下二乙基二硫代氨基甲酸钠(DDC)、氟哌啶醇(Hal)、L-色氨酸(L-Trp)、赛庚啶(CYP)等药物对AEE镇痛作用的影响,用紫外分光光度法测定了热刺激所致疼痛小鼠全脑中的前列腺素E2(PGE2)含量。结果表明,AEE可明显减少醋酸扭体试验中小鼠的扭体次数,降低热刺激小鼠疼痛反应;可显著降低热刺激所致疼痛小鼠全脑中PGE2的含量和二乙基二硫代氨基甲酸钠对痛觉的敏感度,与氟哌啶醇之间存在明显的协同效应,与L-色氨酸和赛庚啶之间拮抗效应显著。说明AEE具有明显的镇痛作用,镇痛机制可能与其降低小鼠全脑中的PGE2含量以及增加去甲肾上腺素(NE)的含量、阻断多巴胺(DA)受体有关。     

液相色谱法测定饲料中9种氨基甲酸酯类农药残留

建立一种高效液相色谱柱后衍生法测定饲料中9种氨基甲酸酯类农药(涕灭威砜、灭多威、3-羟基克百威、涕灭威、速灭威、克百威、甲萘威、异丙威、仲丁威)残留量的方法。样品采用乙腈提取,氨基固相萃取柱分离净化,浓缩,乙腈定容后,进行反相色谱梯度洗脱分离、柱后衍生化、荧光检测器测定。结果表明,9种氨基甲酸酯类农药在22min内能实现基线分离,方法的回收率为80.0%～110.0%,检出限为0.01mg/kg,定量限为0.05mg/kg。     

海藻酸钠在维生素C磷酸酯钙生产中的妙用

海藻酸钠在维生素C磷酸酯钙的生产中,能起到很好的乳化、成粒作用;在喷雾干燥前,特别是在采用喷雾塔干燥前,添加相当于反应液体干物质重量的180mg/kg海藻酸钠,不但能显著延长凝聚时间,还能提高产品收率.     

阿司匹林丁香酚酯对急性肺栓塞小鼠的保护作用

将80只小鼠随机均分为8组,即溶剂对照组、模型组、阿司匹林组、丁香酚组、联合给药组和阿司匹林丁香酚酯低、中、高剂量组,每组10只。各组灌胃给予相应药物,每天1次,连续7 d,最后1次给药1 h后,除溶剂对照组外的各组小鼠尾静脉注射胶原和肾上腺素,制备小鼠肺栓塞模型,溶剂对照组小鼠尾静脉注射等体积生理盐水。观察急性肺栓塞小鼠在15 min内的存活情况,记录存活时间,计算存活率和肺系数,并制备小鼠肺组织病理切片,观察肺部病理变化,鉴定小鼠急性肺栓塞模型是否成功建立。结果显示,该小鼠肺栓塞模型成功建立,阿司匹林丁香酚酯能够增加肺栓塞小鼠的存活率,显著延长肺栓塞小鼠的存活时间,并显著降低肺栓塞小鼠的肺系数。结果表明,阿司匹林丁香酚酯能够对肺栓塞小鼠产生一定程度的保护作用。