我国商业鸡群多种免疫抑制性病毒共感染的研究

在2000～2006年间通过对来自我国4个主要养鸡省区的193个商业鸡群共808只病/死鸡分别进行5种免疫抑制性病毒CIAV、IBDV、MDV、REV和ALV感染情况的调查,结果显示:CIAV、IBDV、MDV、ALV和REV的群阳性率和个体阳性率分别为65.56%和30.94%、49.14%和23.98%、35.63%和12.5%、12.22%和4.29%、12.22%和4.16%,其中被检鸡二重及多重混合感染的总阳性率为31.73%,最常见的共感染形式是MDV CIAV(阳性率为10.02%)和MDV ALV(阳性率为8.50%);7个不同品种鸡被各种病毒的感染率也不尽相同。结果证实,免疫抑制性病毒的感染在4个省区的商业鸡群中普遍存在。     

2021年北京市种鸡场禽网状内皮组织增殖病和禽白血病监测

为了解北京市种鸡场禽网状内皮组织增殖病病毒(REV)和禽白血病病毒(ALV)的流行情况,采用ELISA方法,对2021年从9个区27个种鸡场采集的2 660份血清和2 660份蛋液样品分别进行了REV抗体和ALV p27抗原监测。监测结果显示:2021年北京市种鸡场的REV抗体和ALV p27抗原个体表观阳性率分别为33.83%和1.54%,真实阳性率分别为34.53%(95%CI:32.72%～36.33%)和1.57%(95%CI:1.10%～2.05%);群体表观阳性率分别为81.48%和29.63%,真实阳性率分别为83.14%和30.23%。除第四季度未检出REV抗体阳性外,其他季度均检出这2种病原,其中第三季度ALV个体阳性率最高(4.86%),与其他季度差异有统计学意义(P<0.05),第二季度REV个体阳性率最高(85.40%),不同季度间的REV个体阳性率差异显著(P<0.05)。祖代群和父母代群均检出REV抗体和ALV p27抗原阳性个体,且阳性率差异均有统计学意义(P<0.05)。结果表明,北京市种鸡场REV和ALV分布广泛,感染较严重,净化效果...     

2016年鲁北地区鸡群病毒性肿瘤病例的检测分析

为了解鸡马立克病病毒(MDV)、禽白血病病毒(ALV)和禽网状内皮组织增生症病毒(REV)在鲁北地区鸡群中的感染情况,对来自21个鸡群的送检病例进行了病原核酸的PCR检测.结果显示,MDV阳性率为28.5%,ALV-J阳性率为23.8%,REV阳性率为14.3%,肿瘤病毒的二重感染率为28.6%.结果表明,3种肿瘤病毒在鲁北地区蛋鸡和地方品种鸡群中的感染严重,病毒的混合感染较多.因此,做好MD的疫苗防护,对ALV-J及REV的感染状况要进行定期检测,控制好养殖环境,尽量避免3种肿瘤病毒的继发感染.     

云南省地方品种鸡群4种垂直传播病毒血清流行病学调查

为了解云南省地方品种鸡群中禽白血病病毒(ALV)、禽网状内皮组织增生症病毒(REV)、鸡传染性贫血病毒(CAV)和禽脑脊髓炎病毒(AEV)的感染情况,采用ELISA方法对云南省滇东、滇西、滇中、滇南和滇北5个区域8个地方品种鸡群的2295份血清样品进行了上述4种垂直传播病毒的抗体检测。结果显示:云南省8个地方品种鸡群中,ALV、REV、CAV和AEV平均抗体阳性率分别为27.02%、72.77%、98.47%和76.25%,二重、三重、四重感染率分别为32.90%、36.38%、15.90%;不同区域、不同品种鸡群中均存在上述4种病原的感染,抗体阳性率有一定差异,但无规律性。结果表明,云南省地方品种鸡群中4种垂直传播病毒感染率较高,流行面较广,且呈现严重的混合感染状态。结果提示:应重视这4种可垂直传播病原的流行控制,谨防因病毒混合感染导致重大疫病免疫失败;继续加强抗体检测,及时淘汰阳性鸡群,净化种群,同时定期进行疫苗污染监测,提升饲养管理水平,保障云南省地方鸡种质资源的安全健康发展。     

我国进口种鸡群禽白血病及禽网状内皮组织增生症的血清学检测

为了解河北进口种鸡群禽白血病病毒(ALV)及禽网状内皮组织增生症病毒(REV)的感染情况,对实验室留存的2011—2013年间来自美国、加拿大和法国的15批进口种鸡的血清样品450份,通过ELISA方法进行ALV-A、B亚群和REV的抗体检测。结果共有8批28份样品为ALV-A、B亚群抗体阳性,群体阳性率和个体阳性率分别为53.3%和6.2%;未检出REV抗体阳性样品。结果表明目前我国进口种鸡群中存在一定比例的禽白血病病毒A、B亚群抗体阳性个体。     

江苏地区发病鸡4种免疫抑制性病原混合感染的检测

为了解鸡免疫抑制性病原混合感染的流行情况及其感染间相互作用的关系,本研究应用PCR方法对来自江苏地区不同鸡群的376只病鸡进行鸡贫血病毒(chicken anemia virus,CAV)、马立克氏病病毒(Marek’s disease virus,MDV)、网状内皮组织增生症病毒(reticuloendotheliosis virus,REV)和禽白血病病毒(avian leukosis virus,ALV)的检测。结果显示CIAV、MDV、REV和ALV的检出率分别为37.50%、25.00%、12.77%和33.51%,CIAV、MDV、REV和ALV的单一感染检出率分别为15.16%、9.04%、1.60%和12.50%,被检鸡混合感染的总检出率为30.59%,二重感染以CIAV+ALV最为常见,检出率为7.45%,三重感染以CIAV+MDV+ALV最为常见,检出率为3.46%,四重感染检出率为1.06%。4种免疫抑制性病原感染间相互作用的比较经统计学分析表明,CIAV和REV感染间存在相互促进的趋势(P0.01)。结果表明,鸡群免疫抑制性病原的混合感染普遍存在,与临床上鸡群发病率高、多种病原感染、疫苗免疫效果不佳、生长缓慢等密切相关。     

河北省蛋种鸡3种免疫抑制病的感染情况分析

为了解河北省蛋种鸡禽白血病(AL)、禽网状内皮组织增殖症(RE)和鸡传染性贫血(CIA)的感染情况,采集河北省5个地区的7个种鸡场的种蛋997枚以及血清487份,采用ELISA的方法进行ALV p27抗原、REV和CIAV的抗体检测。结果显示,ALV p27抗原的场阳性率为85.71%(6/7),个体阳性率为2.71%(27/997);REV抗体场阳性率为100%(7/7),个体阳性率为11.29%(55/487);CIAV抗体场阳性率为100%(7/7),个体阳性率为100%(487/487)。其中海兰灰ALV p27抗原的阳性率最高,为6.04%,依次为坝上长尾鸡为4.31%,北京油鸡3.33%,太行鸡2.07%,而海兰褐和巴布考克B380未检测出ALV p27抗原。海兰褐REV抗体的阳性率最高,为29.27%,依次为巴布考克B380为14.75%,太行鸡为4.6%,坝上长尾鸡阳性率4.31%,海兰灰为2%,北京油鸡未检测出REV抗体。CIAV抗体不同品种的检出率都是100%。结果表明不同养殖场和品种间二重感染或三重感染较为普遍。     

鸡传染性贫血病病毒与三种致家禽肿瘤病毒混合感染的流行病学研究

根据鸡传染性贫血病病毒(CIAV)、马立克氏病病毒(MDV)、网状内皮组织增生症病毒(REV)、禽白血病病毒(ALV)基因保守序列各设计1对特异性引物,采集102份发病家禽的肝脏、脾脏、胸腺和法氏囊等病料,通过RT-PCR和PCR方法进行检测。结果显示:CIAV、MDV、REV、ALV单一感染检出率分别为23.5%(24/102)、4.9%(5/102)、1.0%(1/102)、8.8%(9/102);CIAV和MDV、CIAV和REV、CIAV和ALV、MDV和REV、MDV和ALV、REV和ALV二重感染率分别为2.0%(2/102)、4.9%(5/102)、10.8%(11/102)、2.0%(2/102)、2.0%(2/102)、1.0%(1/102);三重感染中CIAV、MDV和REV为0(0/102),CIAV、MDV和ALV为3.9%(4/102),CIAV、REV和ALV为7.9%(8/102),MDV、REV和ALV为1.0%(1/102);四重感染率为1.0%(1/102)。26份样品中四种病毒均未检出。CIAV阳性病料与阴性病料相对应的REV共感染率具有极显著差异(P0.01),CIAV阳性病料与阴性病料相对应的ALV共感染率具有显著差异(0.01P0.05)。研究结果进一步丰富了四种病毒的流行病学数据。     

肉种禽网状内皮增生症、鸡传染性贫血和禽白血病血清学调查

对不同种鸡场不同周龄肉种鸡进行REV、CAV和ALV（A、B亚群）抗体检测。在572份血清样品中，除了一个8．1周龄和15周龄鸡群CAV抗体阳性率分别为13．3％和75％外，其它鸡群无论是否进行CAV疫苗免疫，抗体阳性率均为100％。在212份血清样品中，REV抗体阳性率在16．7％～62．5％之间；ALV（A、B亚群）抗体阳性率在0％～75％之间。本研究结果表明，所检测种鸡群中存在3种免疫抑制性病毒的感染或混合感染。     

2014年广西地方鸡群病毒性肿瘤病例的检测分析

2014年,广西地区部分鸡群发生了以内脏出现各种肉眼可见肿瘤、生长阻滞、消瘦和采食量下降为特征的病例。通过对病鸡进行肉眼剖检观察,对病料组织分别进行肿瘤病毒PCR检测、DF-1细胞分离培养及其细胞培养上清进行禽白血病病毒(ALV)p27抗原检测,结果显示12批病例中,单独感染ALV的鸡群有5群,单独感染马立克氏病病毒(MDV)的鸡群有1群,ALV与MDV的二重混合感染鸡群有4群,MDV和网状内皮组织增殖病病毒(REV)的二重混合感染的鸡群有1群,ALV、MDV和REV的三重混合感染有1个鸡群。表明ALV的感染及其与其他肿瘤病毒的共感染是当前临床肿瘤病例的主要病因。     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.     

Helminth and protozoan parasites in dogs and cats in Belgium

This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.     

Sanguinarine metabolism and pharmacokinetics study in vitro and in vivo

Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (C_max, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their C_max (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T_1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (C_ss) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.     

Chlortetracycline in swine-bioavailability and pharmacokinetics in fasted and fed pigs

Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).     

2005年国内蛋、肉鸡市场分析回顾及2006年走势预测

2005年如果没有年底的禽流感疫情,对于我国蛋鸡、肉鸡生产来说应该是一个非常完美的丰收年,是哪些因素导致了2005年蛋鸡市场如此好的行情?2006年我国家禽市场又将走向何方?……作者对以上热点问题进行了深入分析研究,供读者参考。     

Pharmacokinetics of penicillin-G in ewes and cows in late pregnancy and in early lactation

Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.     

Mycobiota and aflatoxins in raw materials and pet food in Brazil

Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.