Characterization of backyard poultry production systems and disease risk in the central zone of Chile

Backyard poultry production systems (BPS) are an important and widespread form of poultry production. There is a common perception that biosecurity standards in BPS are generally poor and BPS are usually associated with animal diseases and zoonoses. In this study BPS were identified in the vicinity of six wetlands, having these a higher risk of presenting and introducing avian diseases such as HPAI and Newcastle disease, as defined by the national veterinary services, in to Chile's main poultry production area. BPS were characterized through a field questionnaire and the main areas covered by the survey were BPS structure, biosecurity and value chain. The BPS identified in this study share most characteristics on biosecurity, poultry management and product commercialization, but it was possible to identify a certain degree of variation within and among the study sites. BPS in Chile are similar to those in other regions, with a relatively small flock size (average 37 birds), a low level of biosecurity measures and lack of poultry disease management. Management findings include that most farmers used mixed/partial confinement, with low or no biosecurity and disease control measures in place. Eggs were the main output and were used mainly for home consumption or sale at local markets. Sick birds' treatment with drugs approved for other species or for human use could represent a risk to human health, owing to the possible presence of drug residues in poultry products. Despite the different structures of the poultry sector worldwide, BPS can play a major role in disease maintenance and spread because its management conditions characteristics and the lack of animal health services adapted to these production systems. This should be an alert message to the veterinary authorities to improve coverage of veterinary assistance and surveillance activities in backyard poultry production.     

The limitations of a feed/water based heat-stable vaccine delivery system for Newcastle disease-control strategies for backyard poultry flocks in sub-Saharan Africa

Backyard poultry are a major contributor to egg and meat consumption in sub-Saharan Africa and an important source of income for many rural producers. Production throughout Africa is severely constrained by continuing outbreaks of Newcastle disease. The livestock-service sector lacks the resources and infrastructure to control Newcastle disease in extensive flocks without the active participation of producers. The development of ‘heat-stable’ Newcastle disease vaccines offers a potential solution. Trials over the last two decades have examined the effectiveness of heat-stable vaccines in both controlling Newcastle disease and in involving the rural community in control strategies. Constraints highlighted include the reliability of the vaccines using alternative delivery methods and the capacity of rural communities to apply those methods. The search for appropriate Newcastle disease-control strategies in extensive poultry systems should focus on policies and methodologies that incorporate the wider concerns and priorities of extensive producers.     

The limitations of a feed/water based heat-stable vaccine delivery system forNnewcastle disease-control strategies for backyard poultry flocks in sub-Saharan Africa

Backyard poultry are a major contributor to egg and meat consumption in sub-Saharan Africa and an important source of income for many rural producers. Production throughout Africa is severely constrained by continuing outbreaks of Newcastle disease. The livestock-service sector lacks the resources and infrastructure to control Newcastle disease in extensive flocks without the active participation of producers. The development of 'heat-stable' Newcastle disease vaccines offers a potential solution. Trials over the last two decades have examined the effectiveness of heat-stable vaccines in both controlling Newcastle disease and in involving the rural community in control strategies. Constraints highlighted include the reliability of the vaccines using alternative delivery methods and the capacity of rural communities to apply those methods. The search for appropriate Newcastle disease-control strategies in extensive poultry systems should focus on policies and methodologies that incorporate the wider concerns and priorities of extensive producers.     

Poultry production and constraints in Eastern Province of Rwanda: case study of Rukomo sector,Nyagatare district

A study was conducted in Rukomo sector, Nyagatare district, to determine the status of poultry production. A structured questionnaire was used to collect data from 100 poultry farmers randomly as 20 farmers from each of the five cells. Data were analyzed using SPSS version 16 and presented in chart and tables. The majority of the farmers (84%) reared their poultry in free range system while 10% practiced semi-intensive and only 6% did intensive production. Only 12% of the respondents kept exotic poultry breeds. The breeding stock were mostly obtained from local markets (63%) and the average flock size was about 1–10 birds per homestead (70%). The confinement of poultry at night was either in the main domestic house (33%), in kitchen (32%), or in separate poultry house (35%). Flock records were rare and kept by only 9% of respondents. Poultry products were reportedly at high demand by 87% of respondents and 89% farmers reported profit from their enterprises. Lack of veterinary and financial assistance was reported by 72% of respondents. Newcastle disease (57%) was the main health constraint followed by ectoparasites and internal worms. Many farmers (50%) were in dire need of veterinary assistance and financial support to improve their poultry enterprises. Poor management practices were reported to be one of the crucial factors leading to poor production. Lack of quality feeds (38%) and feeding of poultry, credit (20%), and poor market accessibility (19%) were the main challenges reported.     

不同方法提取高致病性禽流感及新城疫病毒RNA效果的比较分析

高致病性禽流感以及新城疫对禽养殖户危害巨大,应用荧光RT-PCR方法对高致病性禽流感、新城疫病毒进行检测在病原学检测中占据优势。而荧光RT-PCR检测的核心是核酸物质的提取。本文将离心柱内硅基质膜提取法（柱膜法）与磁珠法作比较,探讨更适合基层兽医实验室的核酸提取方式。     

Molecular characterization of Newcastle disease viruses isolated from rural chicken in northwest Ethiopia reveals the circulation of three distinct genotypes in the country

Newcastle disease (ND) is a highly contagious disease that affects many species of birds and causes significant economic losses to the poultry industry worldwide. Fifteen Newcastle disease virus (NDV) isolates obtained from rural chickens in northwest Ethiopia in 2011 and 2012 were characterized genotypically. The main functional region of the F gene was amplified and sequenced (260 nucleotides). Among the Ethiopian NDV isolates, 2 isolates had the virulent motif ¹¹²R-R-Q-K-R-F¹¹⁷ at the cleavage site of the fusion protein while 13 isolates contained the lentogenic motif ¹¹²G-G/R-Q-G-R-L¹¹⁷. Phylogenetic analysis based on the variable region of the F gene indicated that the two isolates exhibiting the virulent motif belonged to lineage 5 (genotype VII) subgenotype d and the remaining 13 isolates were grouped into lineage 2 (genotype II). The nucleotide sequences of lineage 5 isolates were genetically related to the Sudanese NDV isolates, suggesting potential epidemiological link of ND outbreaks between neighbouring countries. The lentogenic strains shared similarities with La Sota vaccine strain and probably originated from the vaccine strain either through direct exposure of birds to the live vaccine or to infectious La Sota-like strains circulating in rural poultry. This study provides genetic evidence on the existence of different NDV genotypes circulating in the rural poultry in Ethiopia. The virulent NDV continues to be a problem in poultry sector in Ethiopia, and their continuous circulation in rural and commercial poultry calls for improved surveillance and intensified vaccination and other control measures.     

Bioactive berry juice byproducts as alternative and natural inhibitors forSalmonella Gallinarum andSalmonella Pullorum

Fowl typhoid and pullorum disease, caused bySalmonella enterica serovars Gallinarum biovarsSalmonella Gallinarum (S. Gallinarum) andSalmonella Pullorum (S. Pullorum), remain large threat to the organic poultry industry. These infections are serious threats to poultry health and overall flock viability especially at their early age. These avian pathogens cause a significant production loss and price increase of poultry products especially organic poultry products due to lack of antibiotics use. As a result, alternative intervention strategies have become an urgent demand of the farmers. Natural antimicrobials from plant products, such as bioactive compounds from berry juice byproducts can play important role in such a situation. In this study, we showed that blackberry and blueberry pomace extracts inhibitedS. Gallinarum andS. Pullorum growth in vitro. Two mg gallic acid equivalent (GAE)/mL blackberry or blueberry pomace extract reduced the growth of both pathogens by more than 5 logs at 24 h in broth. In semisolid poultry fecal medium, which contains poultry gut nutrients available to the gut bacteria, 1.0 mg GAE/mL of both extracts reduced the growth of these pathogens by more than 2 logs at 24, 48, and 72-h time points.S. Gallinarum andS. Pullorum were completely inhibited by 1.0 mg GAE/mL both extracts in water. The growth of probioticLactobacillus plantarum (L. plantarum) was unaffected in the presence of berry pomace extracts in broth but growth stimulation was observed in fecal medium when grown in presence of these extracts at 72 h. Moreover,L. plantarum completely inhibitedS. Gallinarum andS. Pullorum when co-cultured in fecal medium in the presence of 1.0 mg GAE/mL of both pomace extracts. In this study, we conclude that bioactive extracts from berry pomace are potential antimicrobials for organic producers which will modulate poultry gut microflora and improve productivity, product safety, and quality.     

The influence of gender and group membership on food safety: the case of meat sellers in Bodija market,Ibadan, Nigeria

Four Newcastle disease virus isolates were recovered from asymptomatic guinea fowl (Numida meleagris galeata) and Muscovy ducks (Cariana moscata). For the purpose of molecular identification and phylogeny, phylogenetic characterization was performed to identify the pathotypes. All four viruses had a cleavage motif ¹¹²RRQKRF¹¹⁷ which is characteristic of virulent strains. The isolates grouped with viruses previously reported as sub-lineage 5g from chickens in Nigeria. This study report for the first time the identification of the virulent sub-lineage 5g Newcastle disease virus from apparently healthy guinea fowl and domestic ducks in Nigeria, and since infections were sub-clinical, it suggest that these species could play a role in the spread and transmission of virulent Newcastle disease virus that can infect other poultry. The isolation and identification of virulent Newcastle disease virus in these unusual hosts and the high sequence similarity (99.3–100 %) between viruses in this study with strains reported for Niger and Cameroun gives insights into the ecology of virulent Newcastle disease viruses and suggests some cross-border movement and trade in live poultry.     

The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non‐monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non‐monetary benefit) which was mainly obtained from other private actors and media.     

Early history of regulatory requirements for poultry biologics in the United States

Congress passed the Virus-Serum-Toxin Act in 1913, giving the U.S. Department of Agriculture (USDA) authority to prevent the importation or interstate shipment of worthless, contaminated, dangerous, or harmful veterinary biological products. The passage of this act marked the beginning of regulatory requirements for veterinary biological products in the United States. In 1913, only a few biologics establishments produced products for the poultry industry. The first license issued by the USDA for a poultry product was in 1918 to the University of California, Berkeley, for fowlpox vaccine. The list of biological products for poultry grew slowly in the 1920s. However, this began to change with the licensing of laryngotracheitis vaccine in 1933; pigeonpox vaccine in 1939; several Newcastle disease vaccines (inactivated in 1946, Roakin strain in 1948, B1 strain in 1950, and La Sota strain in 1952); and the first bronchitis vaccine in 1953. With the development of these and other new products, the biologics industry began to move its emphasis on hog cholera serum and virus to one based on the production of numerous new vaccines and bacterial products. The USDA's approach to the regulation of biologics in the early 1950s was still geared to the production of hog cholera products; however, as a result of the intervention of a group of dedicated poultry scientists, who were concerned about the poor performance of Newcastle disease vaccines, this soon changed. This presentation describes the initiation and development of modern standards for poultry biologics that occurred as a result of this intervention. The development and improvement of standards and regulatory requirements to address mycoplasma, leukosis, and other extraneous virus contaminations in chicken embryo origin products are reviewed. The licensing of products to meet new and emerging disease problems in the poultry industry and the close interaction among research scientists, poultry industry, biologics manufacturers, and government regulatory officials that has been needed to ensure the availability of products that meet appropriate standards of purity, safety, potency, and efficacy are also addressed.     

Village-based indigenous chicken production system in north-west Ethiopia

Surveys using both purposive and random sampling methods was carried out in four zones of north-west Ethiopia to describe the village-based poultry production systems and constraints in order to design future improvement and conservation strategies. The majority of the respondents were female (74.16%). This indicated that most of the time the women, whether in male-headed or female-headed households, are responsible for chicken rearing while the men are responsible for crop cultivation and other off-farm activities. About 99% of the respondents gave supplementary feeds to their chickens. Almost all farmers provided night shelter for their chickens, in part of the kitchen (1.36%), in the main house (39.07%), in hand-woven baskets (7.29%), in bamboo cages (1.51%) or in a separate shed purpose-made for chickens (50.77%). The major causes of death of chickens during the study were seasonal outbreaks of Newcastle disease (locally known as fengele) and predation. It is important to collect and conserve local poultry breeds before they are fully replaced by the so-called improved breeds. As most of the poultry production is managed by women, focusing on training and education of women will enable not only the improvement of poultry production but also family planning and the overall living standards of the family and the community.     

Adoption and failure rates of vaccinations for disease prevention in chicken farms in Jos,Nigeria

Vaccinations against diseases to prevent disease outbreaks are strategic to disease prevention, but vaccination failures may constitute a challenge in practice. This study was aimed at assessing the adoption and failure rates of vaccinations in 80 chicken farms in Jos, Nigeria. Data were obtained through a structured questionnaire validated by interviews and checking of farm and veterinary records. Vaccination score (0–1) from the vaccination checklist (5 for broilers and 12 for layers) and vaccination procedure score (0–1), based on scored adopted procedures, were calculated for each farm. Vaccine effectiveness was calculated for each vaccine using the odds ratio from the association of frequencies of disease outbreaks in vaccinated and unvaccinated flocks. Farmers used more of imported than local vaccines. Vaccination procedure and vaccination scores did not influence frequencies of disease outbreaks, but vaccination scores tended to non-robustly correlate (r = − 0.89, p > 0.05) with rates of disease outbreak. Vaccination rates were highest against Newcastle disease and infectious bursal disease, and their vaccinations also had the highest effectiveness. There was an association (p = 0.009) between composite vaccination rates and disease outbreaks with 2.1 odds of outbreaks in vaccinated than unvaccinated flocks. Vaccination failures occurred in the use of 11 out of 12 vaccines and the highest failure rate (47.9%) was in vaccination against coccidiosis. Therefore, vaccination failure is a critical factor in poultry vaccination practice within the locality. The adoption of poultry vaccinations needs to be strategised in the context of a national poultry vaccination policy in order to promote effective poultry disease prevention and control.

     

鸡新城疫流行原因分析及防控

鸡新城疫是一种由新城疫病毒引起的急性、高度致死性的严重传染病,在全球范围内广泛流行,曾在世界范围内引起三次大的流行,给养禽业造成了巨大的经济损失,严重影响了养鸡业的发展。论文通过分析全国各地区新城疫的流行现状,探讨其流行原因,并通过分析新城疫毒株基因变异等,为我国鸡新城疫的防控工作提供一定的参考,通过对养殖户日常饲养管理方案的分析,提出科学规范可行的饲养方案,有效的做好新城疫的防控工作,更好的服务社会。     

Husbandry and trade of indigenous chickens in Myanmar—Results of a participatory rural appraisal in the Yangon and the Mandalay divisions

There is a variety of professions working with village chickens in developing countries, including farmers, veterinarians and chicken traders. People from all these occupations were involved in a participatory rural appraisal to investigate husbandry practices and trade of village chickens in Myanmar. Data were collected in two climatically different regions of the country, in the Yangon and in the Mandalay divisions. The breeding and training of fighting cocks was practised only in the Mandalay division, with well-trained birds sold for very high prices. Apart from this, chickens were raised in both regions mainly for small disposable income and were generally sold when money was needed, in particular during religious festivals. Chicken traders on bicycles, often called ‘middle men’, usually purchase birds from farmers in about 10 villages per day. Several ‘middle men’ supply birds to wealthier chicken merchants, who sell these birds at larger chicken markets. There is in general limited knowledge among farmers about the prevention of Newcastle disease via vaccination. Commercial indigenous chicken production is practised in Myanmar, but family poultry farming dominates indigenous chicken production in the country.     

山东省新城疫病毒的分离鉴定及资源平台的建立

作者根据山东省家禽养殖分布及新城疫病发报道进行病样采集,通过病毒分离培养、血凝试验及血凝抑制试验、电镜观察、病毒的最小致死剂量致死鸡胚的平均死亡时间和1日龄雏鸡脑内接种致病指数测定初步判定和描述新城疫病毒（newcastle disease virus ,NDV）的生物学特性,以RT-PCR试验进行最终鉴定,共分离到60株毒株,按照兽医微生物资源描述规范的框架和数据录入要求,完成病毒资源标准化整合,并录入中国兽医微生物资源信息网的数据库,建立了山东省新城疫病毒资源平台。     

Do vaccination interventions have effects? A study on how poultry vaccination interventions change smallholder farmer knowledge,attitudes, and practice in villages in Kenya and Tanzania

Poultry are important for many poor households in developing countries, but there are many constraints to poultry production, including disease. One of the most important diseases of chickens is Newcastle disease (ND). Even though there are effective vaccines against this disease available in most countries, uptake by small-scale poultry keepers is often low. In this study, two areas in Kenya and Tanzania were studied, where some villages had received additional support to get vaccination and other villages had not. In Kenya, 320 households from 10 villages were interviewed, of which half of the villages had active promotion of vaccination through village-based advisors. In Tanzania, 457 households were interviewed, of which 241 came from villages that have had active support through either a project or government extension services. Knowledge about vaccines and the attitudes towards vaccinating against ND was evaluated using mixed multivariable logistic models. Results indicate that in Kenya, the most important determinants for understanding the function of a vaccine were having had support in the village and to have knowledge about ND signs, while in Tanzania gender and previous vaccine use were important in addition to having had support. Attitudes towards vaccination were mainly determined by knowledge, where more knowledge about how vaccines work in general or about ND contributed to more positive attitudes. Among Kenyan farmers that had never used the vaccine before, the amount of birds they lost to disease and predators also influenced attitudes. In conclusion, this study supports the notion that knowledge is a very important component of extension support and that simply making vaccines available may not be sufficient for high levels of uptake.

     

Diseases of free-ranging chickens in the Qwa-Qwa District of the northeastern Free State province of South Africa

A total of 177 free-ranging chickens from 19 Qwa-Qwa villages were bled from wing veins over a period of 6 months (June-November 2000). Serological tests indicated that 5% of chickens tested had been exposed to Newcastle disease, 43% to infectious bronchitis and 63% to Mycoplasma gallisepticum infection. McMaster and Visser sieve techniques were used to determine helminth and coccidia from pooled fresh faecal samples. Helminths isolated in 37% of the villages investigated were Heterakis, Ascaridia and Capillaria species. Eimeria species were also isolated in 32% of the villages investigated. The red fowl mite (Dermanyssus gallinae) was isolated from some of the birds and their nests. Data from a questionnaire survey indicated that all farmers interviewed had never received any technical support and that their chickens had never been vaccinated against any avian diseases. Only 10.5% of the owners interviewed had scientific knowledge on poultry diseases. There is an urgent need for the government to support free-ranging poultry farmers by providing subsidised vaccinations and technical support in order to develop and stimulate economic development in impoverished rural areas of South Africa.     

A survey of carcass condemnation at a poultry abattoir and its application to disease management

During a five year period, slaughter records were maintained on flocks of broiler chickens sent to a federally-inspected abattoir in New Brunswick. These records, including data regarding condemnation of both carcasses and portions of broilers, were maintained at the level of the individual producer. Annual meetings and ad hoc consultations with producers, a veterinary poultry specialist, and support groups in the poultry industry (feed mills, breeders, etc.) were used to relay to the various interested parties, information relating to disease conditions.

Following the implementation of this system, condemnation rates dropped by one full percentage point during the first three years, with a slight increase observed during the last two years of the study. At the end of the survey, condemnation rates were 20% less than those of the national average.