混合感染猪繁殖与呼吸综合征和圆环病毒2型猪群的猪瘟抗体变化研究

本试验研究旨在探究猪场发生猪繁殖与呼吸综合征(PRRS)与圆环病毒2型(PCV2)混合感染后,猪群的猪瘟抗体变化,运用RT-PCR、实时荧光RT-PCR与PCR方法,对四川某规模化发病猪场进行高致病性PRRS、猪瘟与圆环2型的病原检测。结果显示高致病性PRRS、圆环2型和猪瘟阳性率分别为54%(19/35)、50%(17/34)、0(0/5)。结合临床症状、病猪剖检变化,确诊为PRRSV与PCV-2混合感染。采集PRRS与PCV-2混合感染病猪血清12份为试验组,本场健康猪只(无临床症状、抗原检测阴性)12份为对照组,运用ELISA试验检测猪群猪瘟抗体,结果显示试验组的猪瘟抗体合格率为33%(4/12),显著低于健康对照组的合格率83.3%(10/12)(P0.05),结果表明PRRS和PCV2混合感染会对猪瘟抗体产生负面影响。     

同一日龄仔猪三种重大动物疫病母源抗体水平检测及比较分析

试验采用正向间接血凝检测猪瘟抗体水平,采用ELISA测定猪口蹄疫和猪高致病性蓝耳病抗体水平。试验结果表明,A、B、C三个规模化养猪场,仔猪在21日龄时猪瘟母源抗体阳性率分别为97.50%、100%、100%;蓝耳病母源抗体阳性率分别为35.00%、28.21%、23.33%;口蹄疫母源抗体阳性率分别为77.50%、51.28%、13.33%。因此,建议农六师垦区规模化猪场21日龄免疫猪高致病性蓝耳病疫苗和猪口蹄疫,1周以后免疫猪瘟疫苗。     

同一日龄仔猪三种重大动物疫病母源抗体水平检测及比较分析

试验采用正向间接血凝检测猪瘟抗体水平,采用ELISA测定猪1：2蹄疫和猪高致病性蓝耳病抗体水平。试验结果表明,A、B、C三个规模化养猪场,仔猪在21日龄时猪瘟母源抗体阳性率分别为97．50％、100％、100％;蓝耳病母源抗体阳性率分别为35．00％、28．21％、23．33％;口蹄疫母源抗体阳性率分别为77．50％、51．28％、13．33％。因此,建议农六师垦区规模化猪场21日龄免疫猪高致病性蓝耳病疫苗和猪口蹄疫,l周以后免疫猪瘟疫苗。     

广西田东县部分猪场四种疫病病原及三种疫病血清学的检测与分析

为了解广西田东县部分猪场猪瘟?高致病性猪繁殖与呼吸综合征(猪蓝耳病)、猪圆环病毒2型和猪伪狂犬病的流行情况，采用RT-PCR方法及PCR方法检测组织样品，对各猪场送检的162份组织样品进行猪瘟病毒(CSFV) 高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)、猪圆环病毒2型(PCV-2)和猪伪狂犬病病毒(PRV)核酸检测。采用ELISA方法对送检临床健康猪群400份血清样品进行CSFV、HP-PRRSV、PRV-gE抗体检测。病原检测结果显示：病料CSFV核酸检测为阴性；HP-PRRSV、PCV2、PRV核酸总阳性率分别：6.79%、40.74%、1.23%;对不同猪群各种病原核酸阳性率分析发现，育肥猪HP-PRRSV阳性率最高，为11.53%,保育猪PCV2阳性率最高，为51.9%,种母猪PRV阳性率最高，为6.45%。抗体检测结果显示：CSFV抗体阳性率为87%,HP-PRRSV抗体阳性率77.5%,PRV-gE抗体阳生率为12.25%。本研究表明，CSFV免疫效果好，并有效地控制了该病在本区域的发生与流行。HP-PRRS、PCV2、PR这3种疫病仍在猪群中散发流行，需要加强防控...     

梧州市猪几种重要传染病的检测与分析

对采自梧州市及其邻近省市的猪样品进行血清学和病原学检测,结果：猪瘟、猪O型口蹄疫、高致病性猪蓝耳病免疫抗体合格率分别为89.1%、87.5%、84.44%,猪蓝耳病、猪伪狂犬病、猪A型口蹄疫、猪布鲁氏菌病野毒抗体全为阴性,猪瘟、高致病性猪蓝耳病（HP-PRRS）、经典猪蓝耳病、猪圆环病毒2型（PCV2）病原感染率分别为6.45%、18.87%、7.55%、16.13%。结果表明,所用疫苗可以有效阻断地方性优势流行毒株感染,高致病性猪蓝耳病病毒和PCV2是危害猪群的重要致病因子,跨境引猪屠宰成为疫病传播的重要风险环节。     

湖南高致病性猪蓝耳病隐性感染情况调查

用ELISA和RT-PCR的方法对采集自湖南省内20个规模场1007份血清和3个市级定点屠宰场50份猪肺门淋巴结进行蓝耳病血清抗体检测和高致病性猪蓝耳病病毒的检测。结果1007份血清中,蓝耳病抗体阳性率为72.9%(734/1007),高致病性猪蓝耳病病毒携毒率为3.2%(32/1007),50份肺门淋巴结病毒阳性率为16%(8/50),其中,蓝耳病免疫与非免疫猪血清其抗体阳性率相差不显著,种猪的抗体阳性率明显高于商品猪,而其病毒携毒率为0%。部分规模猪场和眼观健康的育肥猪存在高致病性猪蓝耳病病毒的隐性感染。     

山东省莱州市部分猪场猪瘟和蓝耳病血清抗体检测

猪瘟和蓝耳病是影响我国养猪业的重大疫病,对其进行定期检测极为重要。为了解规模猪场的猪瘟和蓝耳病的免疫合格情况,2017年4—8月,采用两阶段随机抽样结合便利抽样方法,采集莱州市6个规模猪场的629份血清样品,通过ELISA方法进行猪瘟和蓝耳病免疫抗体水平检测。结果显示:6个猪场的猪瘟和蓝耳病抗体平均阳性率分别为82.19%和92.85%,均高于国家规定的70%的基本要求,但有1家猪场的猪瘟抗体合格率未达到国家规定的最低标准,保育猪群的猪瘟和蓝耳病抗体合格率整体偏低。检测结果表明:莱州市猪场猪瘟和蓝耳病的免疫效果较好,猪群基本能够得到有效保护,但对于抗体合格率偏低的猪场以及保育猪群应注意加强猪瘟和猪蓝耳病的免疫和抗体监测。     

在猪蓝耳病病毒和猪圆环病毒感染猪场利用猪瘟E2基因工程亚单位疫苗控制猪瘟的案例分析

在某个存在多种病毒性病原混合感染的规模猪场,通过使用猪瘟E2基因工程亚单位疫苗与猪瘟ST传代弱毒细胞苗进行免疫对比试验。免疫前该猪场猪瘟抗体水平比较低(平均ELISA阻断率低于40%),猪群表现为不稳定,存活率低,并且病原检测到猪蓝耳病病毒和猪圆环病毒2型;与弱毒苗相比较,猪瘟E2亚单位疫苗免疫后,猪瘟抗体滴度显著升高,猪群成活率明显提升。临床应用结果表明E2亚单位疫苗可以突破免疫抑制的影响,在猪群存在猪蓝耳病和猪圆环病毒病等免疫抑制性疾病的情况下,仍可以稳定提高猪瘟抗体水平,提供有效保护,提升生产成绩。     

新疆库车县猪繁殖障碍性疾病血清学调查与分析

猪繁殖障碍性疾病严重影响着养猪业的发展,为了调查和了解影响库车县猪繁殖障碍性疾病的流行情况。本文对库车县5个不同区域的37户猪场在现场流行病学调查的基础上分断奶仔猪、育肥猪、母猪、公猪采血清,共采血清394份,进行了猪瘟、猪高致病性蓝耳病、猪细小性病毒病、猪伪狂犬病、猪弓形体病、猪圆环病毒病、猪布鲁氏病血清学检测。实验结果猪瘟抗体合格率68.02%;猪高致病性蓝耳病体合格率74.4%;猪细小病毒病阳性率27.4%;猪伪狂犬病阳性率13.7%;猪圆环病毒病阳性率83.5%;猪弓形体病阳性率61.4%;猪布鲁氏病阳性率0%。     

新疆部分地区猪圆环病毒2型抗体检测与分析

为了解2.019年新疆部分地区猪圆环病毒2型抗体水平,本试验采用间接酶联免疫吸附试验(I-ELISA)法对采自5家规模化猪场不同日龄猪的338份血清样品进行猪圆环病毒2型抗体检测与分析。结果显示,猪圆环病毒2型抗体平均阳性率为70.71%(239/338),刚好达到国家规定标准(70%),平均S/P值为1.69,各猪场间猪圆环病毒2型抗体水平差异显著。各日龄段猪群抗体平均阳性率在26%～92%之间,存在一定差异。保育猪平均阳性率最低(26.56%),且低于国家规定标准(70%),只有经产母猪、后备猪和育肥猪的猪群抗体阳性率在70%以上。表明在新疆地区5个规模化化猪场中,有3个猪场的猪圆环病毒2型抗体阳性率未能达到国家标准(70%),需要制定更加合理的免疫程序;哺乳仔猪、保育猪和种公猪平均阳性率低于国家标准,需加强免疫防控。该结果在一定程度上可为新疆部分地区猪圆环病毒2型防疫工作提供一定的参考。     

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.     

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).     

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.     

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.     

Salmonellae and Campylobacters in Household and Stray Dogs in Northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).     

Housing of dogs and cats in shelters and kennels in Switzerland

The study deals with the situation regarding housing of dogs and cats in Swiss shelters and kennels. In shelters, dogs were mainly held inside a cubicle with a small outside yard. In kennels, housing of dogs took place mainly in inside rooms. Usually two or three dogs were kept together. Cats were held in rooms, with or without outside yards, mainly in groups; no establishment preferred exclusively the housing in cubicles. Shelters received on average 183 dogs and 262 cats each year. Among them, about a third were lost animals while the remaining ones were relinquished. The study highlights some possibilities for improvements and the great diversity of the establishments regarding their size, infrastructure, housing conditions and aims.