癸氧喹酯抗柔嫩艾美耳球虫洛阳分离株的效果试验

以抗球虫指数(Anticoccidial Index,ACI)、料肉比及增重为指标,研究了癸氧喹酯抗鸡柔嫩艾美耳球虫洛阳分离株的效果.结果表明,根据54.4 mg/kg、27.2 mg/kg、13.6 mg/kg体重的剂量按饲料比拌料给药,抗球虫指数(ACI)分别达到183.57、145.53和127.80,与感染不给药组相比,料肉比分别降低30.04％、10.60％和3.18％,高剂量组增重与不感染对照组没有显著差异.癸氧喹酯以54.4 mg/kg体重的浓度拌料可以预防洛阳地区鸡球虫病感染,试验结果为临床上有效利用癸氧喹酯控制鸡球虫病提供了重要依据.     

复方抗球虫药临床效果观察

复方抗球虫药(妥曲珠利-马杜霉素铵溶液)是一种西药复方制剂,主要用于防治鸡球虫病。本试验主要研究复方抗球虫药临床抗球虫效果并进行推广。在临床上治疗经柔嫩艾美耳球虫南通株人工接种的AA肉仔鸡,结果表明,妥曲珠利-马杜霉素铵抗球虫指数大于180,属于高效抗球虫药物。在各剂量组鸡的粪便和盲肠中均没有检查到球虫卵囊,说明没有耐药的突变虫株。对鸡球虫病的防治效果显著优于马杜霉素铵预混剂和妥曲珠利溶液,对鸡球虫具有高效的防治作用。     

阿德呋啉水溶剂治疗鸡球虫病的试验研究

为了观察阿德呋啉水溶剂治疗艾美耳球虫的效果,试验设5个药物试验组、阳性及阴性对照组。70只13日龄的雏鸡随机分为7组,其中药物试验组鸡只开始给药。给药24 h后,除阴性对照组外,其余组鸡只均接种混合的球虫孢子化卵囊(5万/羽),试验后根据抗球虫指数(ACI)判断抗球虫药的疗效。结果显示所有给药组中65 mg/kg阿德呋啉水溶剂组ACI为185.54,抗球虫效果最好,为高效抗球虫药;其余阿德呋啉试验组ACI均低于180,浓度过高抗球虫效果差;妥曲珠利试验组ACI低于120,为低效抗球虫药。试验得到了最佳的使用浓度,为球虫病的防治提供了方法。     

常山散对人工感染的鸡球虫病疗效研究

为了明确常山散治疗鸡球虫病的疗效和最佳给药剂量,通过人工感染鸡柔嫩艾美耳球虫后在饲料中添加一定比例的药物,试验设常山散组(分别为0.05、0.1、0.3、0.5、0.7、1 g/kg饲料)、妥曲珠利对照组(1.0 m L/L饮水)、感染对照组和健康对照组。结果表明:与感染对照组比较,常山散各剂量组鸡盲肠和十二指肠肿胀明显减轻,血液性内容物明显减少,抗球虫指数分别为85.5、132.7、141.1、128.8、104.2和102.8,均高于感染对照组;常山散按0.1、0.3和0.5 g/kg饲料给药抗球虫指数均高于妥曲珠利对照组(124.8)。结果提示:常山散抗球虫疗效好,且作为中药提取物,绿色环保、低毒、低残留,有望成为新型抗球虫药物。     

具有抗氧化活性的植物提取物在肉鸡球虫病治疗上的应用价值

本文以妥曲珠利作为阳性对照,对四种具有抗氧化活性的植物提取物进行体内抗球虫活性筛选。结果证明吊金钱(160mg/kg)对鸡有毒性,而用紫娇花(35mg/kg)、葡萄(75mg/kg)和艾草(150mg/kg)治疗感染肉鸡可获得与妥曲珠利治疗组肉鸡相当的饲料转化率,并且高于未治疗的阴性对照组。紫娇花非常显著地减少了感染肉鸡的球虫卵囊产生。由此可知,富含抗氧化剂的植物提取物对治疗球虫感染存在潜在的应用价值。本研究表明,紫娇花是治疗球虫病较理想的药物。     

"肉鸡球虫病及其综合防治措施"专栏(四)具有抗氧化活性的植物提取物在肉鸡球虫病治疗上的应用价值

本文以妥曲珠利作为阳性对照,对四种具有抗氧化活性的植物提取物进行体内抗球虫活性筛选.结果证明吊金钱(160mg/kg)对鸡有毒性,而用紫娇花(35 mg/kg)、葡萄(75mg/kg)和艾草(150mg/kg)治疗感染肉鸡可获得与妥曲珠利治疗组肉鸡相当的饲料转化率,并且高于未治疗的阴性对照组.紫娇花非常显著地减少了感染肉鸡的球虫卵囊产生.由此可知,富含抗氧化剂的植物提取物对治疗球虫感染存在潜在的应用价值.本研究表明,紫娇花是治疗球虫病较理想的药物.     

妥曲珠利治疗鸡球虫病用药方案的优化

目前,妥曲珠利的用药时间和用药途径及其治疗效果存在争议。为了确定妥曲珠利对鸡球虫病的最佳用药时间和途径,本试验以自由饮水和灌服两种途径分别在感染球虫孢子化卵囊后24、48、72 h连续用药2 d,通过抗球虫指数（anticoccidialindex,ACI）、排卵囊减少率和死亡率等指标分析妥曲珠利饮水剂合理用药方案。结果表明,感染后24 h用药妥曲珠利可有效控制鸡柔嫩艾美耳球虫病,48 h后治疗效果不佳;嗉囊灌服的治疗效果优于自由饮水。本试验结果为生产中有效利用妥曲珠利控制鸡球虫病提供了重要依据。     

阿德呋啉对人工感染鸡球虫病的疗效实验

阿德呋啉属核苷酸类化合物,通过干扰球虫嘌呤代谢而发挥抗球虫作用。为评价其抗球虫效果,将该药以30、60和90mg/kg浓度添加于饲料中治疗人工感染鸡球虫病,以磺胺喹噁啉500mg/kg浓度拌料给药作为对照。结果表明,阿德呋啉高剂量组(90mg/kg)具有良好的抗球虫效果,其抗球虫指数为183.2,而其中、低剂量组(30、60mg/kg)与磺胺喹噁啉则疗效很差,抗球虫指数均在120以下。故推荐阿德呋啉治疗剂量为90mg/kg。     

三嗪类抗球虫药的研究进展

鸡球虫病是集约化养鸡场最常见的也是危害较严重的疾病之一,特别是在平养式肉鸡中造成的危害更为严重,全世界每年因鸡球虫病造成的经济损失高达20亿英镑.目前我国应用比较广泛的抗球虫药大约有20多种,但绝大部分药物都有很长时间的使用历史,从投入使用的时间来看,近10年来还没有新的抗球虫药问世.三嗪类抗球虫药主要是妥曲珠利、地克珠利以及纳川珠利[1],为广谱抗球虫药,具有高效低毒的特点,是目前用药浓度最低的一种抗球虫药.笔者简要介绍一下三嗪类抗球虫药的研究进展.     

纳川珠利溶液剂对鸡球虫病的药效学研究

对两种不同配方的0.3%纳川珠利溶液剂,分别以6、3、1mg/L三种剂量饮水预防人工感染的鸡柔嫩艾美耳球虫,并用地克珠利预混剂以1mg/kg剂量作为对照。结果显示,0.3%纳川珠利溶液剂的两种配方以上述3种剂量饮水预防鸡球虫病,具有良好的抗球虫效果,抗球虫指数在180以上,属高效范围。表明0.3%纳川珠利溶液剂是纳川珠利的一种高效预防鸡球虫病的良好剂型。     

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。