免疫不同剂量禽流感疫苗对蛋鸡抗体效价的影响

禽流感作为家禽养殖业的最大威胁,通过科学使用禽流感疫苗进行免疫能够有效预防暴发禽流感疫情。本试验对蛋鸡在相同条件下注射不同剂量的禽流感疫苗,间隔相同时间后采样测定抗体的效价,结果表明:首次免疫的剂量0.3 m L/羽、0.4m L/羽、0.5 mL/羽,一个月后测定的(H5+H7)抗体滴度平均值随着免疫剂量的增加而提高,60日龄加强免疫剂量为0.5 mL/羽、0.7 mL/羽、0.9 mL/羽,一个月及两个月后测定的(H5+H7)抗体滴度平均值均保持在最高水平10。试验表明:首次免疫禽流感疫苗剂量为0.5 m L/羽的抗体效价水平最高,加强免疫的不同剂量均能使抗体效价在较长一段时期保持最高水平。     

Molecular evidence of tick-borne hemoprotozoan-parasites (Theileria ovis and Babesia ovis) and bacteria in ticks and blood from small ruminants in Northern Algeria

Using qPCR, standard PCR and/or sequencing, we investigated the presence of tick-associated microorganisms in ticks and blood from sheep and goats from Souk Ahras, Algeria.Borrelia theileri, was detected in (7/120, 5.8%) blood from sheep and (13/120, 10.8%) goats. Anaplasma ovis was screened in (38/73, 52%) Rhipicephalus bursa and (5/22, 22.7%) R. turanicus and in (74/120, 61.7%), (65/120, 54.2%) blood of sheep and goats respectively.Coxiella burnetii tested positive in R. bursa (4/73, 5.5%) and (7/120, 5.8%) blood of sheep and (2/120, 1.7%) goats. Theileria ovis was detected in (50/147, 34%) R. bursa and (3/22, 13.6%) R. turanicus and in (64/120, 53.3%) blood of sheep and (25/120, 20.8%) goats. Babesia ovis was screened positive in (23/147, 15.6%) R. bursa and (7/48, 14.6%) R. turanicus.Our findings expand knowledge about the repertoire of tick-borne microorganisms present in ectoparasites and/or the blood of small ruminants in Algeria.     

Molecular detection of the B1 gene of Toxoplasma gondii in blood samples of female sheep and goats in Tebessa,northeastern Algeria

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis of crucial medical and veterinary importance. It is mainly diagnosed by serological methods which are limited by insufficient sensitivity. Therefore, it is necessary to rely on direct detection of the parasite. The present study was aimed for direct detection of the parasite DNA in the blood samples of sheep and goats using PCR targeting the B1 gene. The study was carried out in 20 small ruminant farms between 2016 and 2018 in Tebessa region, part of north-eastern Algeria, and concerned 227 and 91 aborted female sheep and goats respectively. DNA of T. gondii was detected in 35.24 % and 18.68 % blood samples of sheep and goats respectively (p < 0.001). Molecular prevalence was higher in 13−24 month old female sheep (93.33 %) than 1−12 month old female sheep (14.37 %) (p < 0.0001). While, in goats no significant difference was observed in relation to age. Female sheep that aborted between 1−60 days of gestation were found to be more infected (46.41 %) compared to females that aborted between 61−120 days of gestation (12.16 %) (p < 0.001). Whereas, female goats that aborted between 61−120 days of gestation were found to be more infested (30.77 %) compared to females that aborted between 1−60 days of gestation (16.67 %) (p < 0.001). This study revealed that small ruminants are highly infected with T. gondii, which represents a major risk for the consumer in Tebessa. Further studies are needed to improve our knowledge of the different genotypes of T. gondii infecting small ruminant population.     

Ability of an oral formulation of afoxolaner to protect dogs from Borrelia burgdorferi infection transmitted by wild Ixodes scapularis ticks

A randomized, blinded, negative controlled study was conducted to determine whether treatment with afoxolaner (NexGard^®, Merial, Inc.) would prevent the transmission of Borrelia burgdorferi to dogs by wild caught Ixodes scapularis ticks. Twenty healthy dogs were randomly assigned to two groups of ten dogs each. Ten dogs were treated orally on Day 0 at a dose near the minimum recommended dose of afoxolaner of 2.5 mg/kg (actual doses 2.5–3.1 mg/kg) and ten control dogs were not treated. On Day 28, each dog was infested with approximately 50 adult unfed wild caught I. scapularis that had a 67% B. burgdorferi infection rate (determined by polymerase chain reaction). On Day 33, live ticks were counted and removed. No ticks were found on treated dogs while control dogs had an average of 21.4 ticks. To detect infection, the B. burgdorferi-specific C6 antibody SNAP^® 4Dx^® test (IDEXX) was performed on serum collected before infestation (all dogs seronegative on Days -6 and 27) and on Days 48, 63, 77 and 92. The ten treated dogs remained seronegative through the end of the study (Day 92), while nine out of the ten control dogs were infected, as demonstrated by their seroconversion to being positive for the presence of the B. burgdorferi-specific C6 antibody starting on Day 48. In this study, all dogs treated with NexGard^® 28 days prior to challenge with wild caught I. scapularis ticks were protected from B. burgdorferi infection, while nine out of the ten untreated control dogs were infected.     

能量对蛋鸡卵巢促卵泡素受体mRNA表达及产蛋率的影响

为了探讨不同日粮能量水平对蛋鸡性成熟过程中卵巢促卵泡素受体(FSHR)mRNA表达及产蛋率的影响,试验选取360只体莺相近的8周龄海兰褐壳蛋鸡,采用单因素随机试验,随机分为5个组,每个组4个重复,每重复18只鸡.在蛋鸡采食其他营养成分相同的情况下,配制不同梯度的能量饲料,采用相对定量反转录-聚合酶链反应方法,测定蛋鸡性成熟过程中卵巢FSHR mRNA表达量.结果表明:高能组卵巢FSHR mRNA的表达量呈先升后降的趋势;对照组、低能组随周龄的增加鸡卵巢FSHR mRNA表达量逐渐增加.14周龄,低能Ⅱ组卵巢FSHR mRNA表达量显著低于其他4组(P<0.05);18周龄,对照组鸡卵巢FSHR mRNA表达量显著高于低能Ⅱ组(P<0.05),除对照组外的其他4组间差异不显著(P>0.05);22周龄,对照组与高能Ⅱ组和低能Ⅰ组间没有差异(P>0.05),却显著高于高能Ⅰ组和低能Ⅱ组(P<0.05).鸡22周龄卵巢FSHR mRNA表达量与22、28周龄产蛋率呈极显著正相关(P<0.01),与35周龄产蛋率呈显著正相关(P<0.05),而与46周龄产蛋率无显著相关(P>0.05).结果提示,适当的能量水平可以提高FSHR mRNA的表达,进而提高产蛋率.     

Molecular evidence of vector-borne pathogens in dogs and cats and their ectoparasites in Algiers,Algeria

In Algeria, only limited information is currently available on the prevalence of emergent canine and feline vector-borne diseases. The aim of the present work was to detect by qPCR vector-associated bacteria in stray dogs and cats and their ectoparasites from Algiers.18/117 (15.38%) dogs and 2/107 (1.87%) cats were positive for at least one vector-borne agent. Coxiella burnetii and Bartonella henselae were identified in 1/117 (0.85%) dog individually. Ehrlichia canis DNA was detected in 17/117 (14.52%) dogs. 1/107 (0.93%) cat was positive to C. burnetii and another 1/107 (0.93%) to B. henselae.DNA of Rickettsia massiliae, Rickettsia conorii and E. canis was detected in Rhipicephalus sanguineus. Cat fleas were infected with Rickettsia felis, B. henselae and Bartonella clarridgeiae. B. vinsonii subsp. berkhoffii was identified in Xenopsylla cheopis collected from dogs.The findings of this study indicate that dogs and cats from Algeria are exposed to multiple tick and flea-borne pathogens.     

Molecular epidemiology of bluetongue virus serotype 1 isolated in 2006 from Algeria

This study reports on an outbreak of disease that occurred in central Algeria during July 2006. Sheep in the affected area presented clinical signs typical of bluetongue (BT) disease. A total of 5245 sheep in the affected region were considered to be susceptible, with 263 cases and thirty-six deaths. Bluetongue virus (BTV) serotype 1 was isolated and identified as the causative agent. Segments 2, 7 and 10 of this virus were sequenced and compared with other isolates from Morocco, Italy, Portugal and France showing that they all belong to a ‘western’ BTV group/topotype and collectively represent a western Mediterranean lineage of BTV-1.     

Ge—132在蛋鸡体内的药代动力学

给24只蛋鸡单剂量灌服Ge-132,分别于0.25～12小时采集血液、肝脏、肾脏、脾脏、卵巢和卵子,用石墨炉原子吸收分光光度法测定样品锗含量,进行药时曲线拟合和动力学参数分析。结果表明,血液中锗有2只鸡符合一级吸收单室开放模型,药代动力学参数为T_(1/2ka)0.2562±0.0302h,T_(1/2k) 3.9657±0.7075h,Tp1.1556±0.1332h,Cmax 2.1621±0.4165uσ/ml,AUC10.6164±0.1748mg/L.o;另4只鸡符合一级吸收双室开放模型,参数为T_(1/2k) 0.3996±0.2606h,T_(1/2α) 0.8513±0.1626h,T_(1/2β)4.7368±0.3652h,Tp1.0116±0.4574h,Cmax 2.6134±0.4574μg/ml,AUC13.3926±3.4651mg/Lh,在各种组织器官中均呈现一级吸收单室开放模型,其消除速率以脾脏最快,依次为脾>肝>肾>卵巢>卵子,表明了蛋鸡体内的Ge-132代谢在个体和不同器官隔室间存在很大差异。     

The Influence of the Housing System on Salmonella Infections in Laying Hens: A Review

From 2012 onwards, housing of laying hens in conventional battery cages will be forbidden in the European Union and only enriched cages and non‐cage housing systems such as aviaries, floor‐raised, free‐range and organic systems will be allowed. Although this ban aims at improving the welfare of laying hens, it has also initiated the question whether there are any adverse consequences of this decision, especially with respect to the spread and/or persistence of zoonotic agents in a flock. A zoonotic agent that is traditionally associated with the consumption of eggs and egg products is Salmonella enteritidis. This paper provides a summary of the current knowledge regarding the direct and indirect effects of different housing systems on the occurrence and epidemiology of Salmonella in laying hen flocks.     

Molecular evidence of bacteria in Melophagus ovinus sheep keds and Hippobosca equina forest flies collected from sheep and horses in northeastern Algeria

The sheep ked, Melophagus ovinus, and the forest fly, Hippobosca equina, are parasitic dipteran insects of veterinary importance. As hematophagous insects, they might be considered as potential vectors of diseases which may be transmissible to humans and animals. The purpose of this study was to present initial primary data about these two species in Algeria. To do so, we conducted a molecular survey to detect the presence of bacterial DNA in flies collected in Algeria. A total of 712 flies including, 683 Melophagus ovinus and 29 Hippobosca equina were collected from two regions in northeastern Algeria. Monitoring the monthly kinetics of M. ovinus infestations showed something resembling annual activity, with a high prevalence in January (21.67%) and May (20.94%).Real-time quantitative PCR assays showed that for 311 tested flies, 126 were positive for the Bartonella spp. rRNA intergenic spacer gene and 77 were positive for Anaplasmataceae. A random selection of positive samples was submitted for sequencing. The DNA of Bartonella chomelii and Bartonella melophagi were amplified in, respectively, five and four H. equina. 25 M. ovinus positive samples were infected by Bartonella melophagi. Amplification and sequencing of the Anaplasma spp. 23S rRNA gene revealed that both species were infected by Wolbachia sp. which had previously been detected in Cimex lectularius bed bugs.Overall, this study expanded knowledge about bacteria present in parasitic flies of domestic animals in Algeria.     

First molecular detection of Dirofilaria immitis (Spirurida: Onchocercidae) infection in dogs from Northern Algeria

Dirofilaria immitis and Dirofilaria repens are mosquito-borne filarioid nematodes that affect dogs and other domestic and wild carnivores, causing heartworm disease and subcutaneous dirofilariosis, respectively. In Algeria, the data about the epidemiology of these infections is largely unknown. The present study was designed to establish the occurrence of D. immitis and D. repens in dogs in Algeria using molecular tools.In 2014 and 2015, a total of 209 dogs over one year of age of different breed and sex, living in Northern Algeria, were examined and blood samples were collected from each dog. The presence of D. immitis and D. repens in these samples was detected by real-time PCR followed by standard PCR and sequencing. Overall, the blood of 209 dogs from two departments was collected and only 3 (1.4%) of the blood samples were found positive for D. immitis DNA. Sequencing of the corresponding amplicon displayed a 99.8% identity to D. immitis, confirming the presence of this mosquito-borne nematode in Algeria. Furthermore, all tested samples were negative for D. repens.     

Prevalence of Toxoplasma gondii infection among animals in Algeria: A systematic review and meta-analysis

Toxoplasma gondii is a zoonotic parasite that can infect all warm-blooded animals. It is responsible for considerable economic losses in some regions and farming systems. This review aims to synthesize current findings on the prevalence and risk factors associated with T. gondii infection in animal species in Algeria. It was performed according to the recommendations of the PRISMA guideline. A total of 14 papers from 1955 to 2020 were eligible to be included in this systematic review and meta-analysis study including a number of 10,187 animals of which 2594 were positive cases (25.46 %) (24.62–26.31 %, 95 %CI). Prevalence of Toxoplasma-infection was 20.04 % in cattle, 22.57 % in sheep, 33.61 % in goats, 28.17 % in horses, 30 % in donkeys, 70.31 % in stray cats, 14.57 % in local rabbits, 30.47 % in dogs and 50.70 % in poultry farms. Adult animals and females were most infected. The highest prevalences were reported in stray cats and poultry. Rabbits were the least infected. This analysis showed a trend of increasing infection since 2015 (R² = 0.129, p > 0.05) which requires further studies to provide better prevention strategies.     

Salmonella in Belgian laying hens: an identification of risk factors

Since the 1980s, the prevalence of Salmonella in Belgian poultry layers and broilers has greatly fluctuated with a rise observed in 2003 and a significant decrease in 2005. In order to alleviate the risk at egg consumer level, it is crucial to understand the factors which influence the contamination and the spread of Salmonella in laying hens. To study such determinants we explored the Belgian data from the 2005 baseline study on the prevalence of Salmonella in laying flocks of Gallus gallus in the European Union. The response variables corresponded to presence or absence of Salmonella from dust and faecal samples taken from the environment of a Belgian layer flock. The explanatory variables included: region of Belgium, sampling time (month the flock was sampled), production type (cage or barn and free range), Salmonella vaccination status, flock age and flock size. Analyses of these data were performed using a bivariate logistic regression model assuming independence between the two responses and bivariate generalized estimating equations model, which incorporates the correlation between the two responses on the same flock. The main risk factor that was identified was rearing flocks in cages compared to barns and free-range systems. The results also showed a significant higher risk for Salmonella for a 1 week increase in flocks’ age as well as with a unit increase in the size of the flock.     

日粮添加柠檬酸对蛋鸡生产性能的影响

采用六处理三重复单因子试验研究0%、0.05%、0.15%、0.25%、0.35%和0.55%柠檬酸添加水平对蛋鸡生产性能的影响,并分析各柠檬酸添加水平对蛋鸡高温期间生产性能的影响。结果表明:0.05%~0.55%柠檬酸添加量显著降低整个试验期和试验高温期的软、破蛋率(P<0.05),对其它生产指标无显著影响(P>0.05)。     

蛋鸡生产过程中两个关键的过渡时期

蛋鸡生产过程中，从育雏期到育成期，随着蛋鸡自身生理特点的变化，饲养管理条件和技术措施需随之改变，这种改变一定要逐步稳妥进行。蛋鸡从育成结束到产蛋开始，各方面也有一个过渡的过程，这一过程中要做的工作较多，是一个比较特殊的时期，有人将17～22周龄称为蛋鸡的预产期，能否平稳度过预产期，有关以后产蛋性能的发挥和蛋鸡的有效利用，实践中应予以重视。     

Effect of prebiotic fructans and organic acids on mineral retention in laying hens

Abstract

The aim of the study was to evaluate the effect of organic acids and prebiotic fructans added to the layer's diet on balance of calcium, phosphorus, and zinc. The basal experimental diet contained 3.30% Ca and 0.60% P, and was either unsupplemented or supplemented with additives as follows: 0.75% inulin, 0.75% oligofructose; 0.50% short-chain fatty acids (SCFA); 0.25% medium-chain fatty acid (MCFA); 0.30% SCFA+0.20% MCFA; and 0.75% inulin+0.50% SCFA. It was concluded that some additives used in the experiment had a positive effect on the mineral balance in hens. Inulin significantly improved retention of Ca, P, and Zn, SCFA – retention of Ca, SCFA+MCFA – retention of Zn, inulin+SCFA – retention of P and Zn.     

硒和铬对蛋鸡脂质代谢及鸡蛋硒含量的影响

本试验旨在研究在蛋鸡日粮中添加酵母硒和吡啶羧酸铬及其互作对蛋鸡生产性能、脂质代谢及鸡蛋品质的影响.选用320只45周龄海赛克斯蛋鸡随机分为4组,每组4个重复,每个重复20只鸡,在基础口粮中分别添加0 mg/kg吡啶羧酸铬(Ⅰ组)、0.4 mg/kg吡啶羧酸铬(Ⅱ组)、0.5 mg/kg酵母硒(Ⅲ组)、0.4 mg/kg吡啶羧酸铬+0.5 mg/kg酵母硒(Ⅳ组),预饲1周,试验从46周龄持续到50周龄,试验期5周(35 d).结果表明,Ⅲ、Ⅳ组产蛋率极显著提高,料蛋比极显著降低(P<0.01).Ⅱ、Ⅳ组血清总胆固醇含量极显著降低(P<0.01),Ⅲ、Ⅳ组血清高密度胆固醇含量极显著升高(P<0.01).Ⅱ、Ⅲ、Ⅳ组蛋黄中的胆固醇含量与Ⅰ组差异极显著(P<0.01).Ⅲ、Ⅳ组与Ⅰ、Ⅱ组相比,鸡蛋硒含量极显著升高(P<0.01).Ⅲ、Ⅳ组在试验开始到第2周末鸡蛋硒含量极显著升高(P<0.01),从第2周末到第5周末,硒含量基本稳定,4个组均进入平台期.结果显示,吡啶羧酸铬极显著降低了血清及蛋黄中的胆固醇含量.酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了蛋黄中胆固醇含量,提高了鸡蛋中的硒含量.同时添加吡啶羧酸铬和酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了血清及蛋黄中的胆固醇含量,提高了血清中高密度胆同醇含量和鸡蛋中的硒含量.     

Molecular detection of Anaplasma phagocytophilum in cattle and Ixodes persulcatus ticks

The tick-borne pathogen, Anaplasma phagocytophilum (A. phagocytophilum), the causative agent of human granulocytic anaplasmosis (HGA), is increasingly becoming a public health concern as an aetiological agent for emerging infectious disease. We found A. phagocytophilum infection in a pooled sample of field-collected Ixodes persulcatus (I. persulcatus) ticks from one district in Hokkaido, Japan. Thus, to further investigate the prevalence in field-collected ticks, we used PCR assays targeting the A. phagocytophilum gene encoding 44 kDa major outer membrane protein (p44) for screening of I. persulcatus ticks and samples from cattle from pastures. Out of the 281 I. persulcatus ticks, 20 (7.1%) were found to harbor A. phagocytophilum DNA. The infection rate for A. phagocytophilum in cattle was 3.4% (42/1251). In future studies, it will be necessary to investigate effects of the infection in order to understand its pathogenesis of A. phagocytophilum in domestic animals.     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响试验

本试验旨在研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响。试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分到4个处理组,各处理组8个重复,每个重复50只鸡。基础饲粮采用为玉米-豆粕型粉状饲粮,处理1饲喂基础饲粮＋60mg／kg-水硫酸锌（以锌计）;处理2饲喂基础饲粮＋60mg／kg乳酸锌（以锌计...