Distribution of Salmonella Serovars and Antimicrobial Susceptibility from Poultry and Swine Farms in Central Vietnam

This study was conducted to estimate the prevalence of Salmonella spp. and their antimicrobial susceptibilities on poultry and swine farms, sampled in 2 regions in Central Vietnam. A total of 67 poultry farms and 46 swine farms were sampled in a period of 5 months (from September 2012 to January 2013). Salmonella spp. was prevalent in 46.3% and 71.7% of poultry and swine farms, respectively. Altogether, 99 non‐typhoidal Salmonella were isolated and the most common serovars were Salmonella Weltevreden (19%), followed by Salmonella Typhimurium (12%) and Salmonella 4,[5],12:i:‐ (11%). Overall, 71 of 99 (72%) Salmonella isolates were resistant to at least one of the 14 antimicrobial agents tested. Both in poultry and swine farms, high levels of resistance were observed for ampicillin, chloramphenicol, ciprofloxacin, sulphamethoxazole and tetracycline. The presence of Salmonella isolates from poultry and swine farms which were resistant to different classes of antimicrobials suggests that alternative control measures to antimicrobials should be implemented. Moreover, an effective policy should be promoted to encourage a prudent use of these agents in animal farming in Vietnam.     

Hepatitis E in southern Vietnam: Seroepidemiology in humans and molecular epidemiology in pigs

Viral pathogens account for a significant proportion of the burden of emerging infectious diseases in humans. The Wellcome Trust‐Vietnamese Initiative on Zoonotic Infections (WT‐VIZIONS) is aiming to understand the circulation of viral zoonotic pathogens in animals that pose a potential risk to human health. Evidence suggests that human exposure and infections with hepatitis E virus (HEV) genotypes (GT) 3 and 4 results from zoonotic transmission. Hypothesising that HEV GT3 and GT4 are circulating in the Vietnamese pig population and can be transmitted to humans, we aimed to estimate the seroprevalence of HEV exposure in a population of farmers and the general population. We additionally performed sequence analysis of HEV in pig populations in the same region to address knowledge gaps regarding HEV circulation and to evaluate if pigs were a potential source of HEV exposure. We found a high prevalence of HEV GT3 viral RNA in pigs (19.1% in faecal samples and 8.2% in rectal swabs) and a high HEV seroprevalence in pig farmers (16.0%) and a hospital‐attending population (31.7%) in southern Vietnam. The hospital population was recruited as a general‐population proxy even though this particular population subgroup may introduce bias. The detection of HEV RNA in pigs indicates that HEV may be a zoonotic disease risk in this location, although a larger sample size is required to infer an association between HEV positivity in pigs and seroprevalence in humans.     

Productivity and socio-economic profile of dairy cattle farmers amongst rural smallholder communities in northern Vietnam

The objective of this field questionnaire survey was to describe the productivity and socio-economic profile of dairy cattle farmers in northern Vietnam considering regional differences in rural smallholder farming communities which have been targeted by a governmental dairy development policy. Using two-stage cluster sampling, a total of 99 dairy farming households (11 per commune) were recruited from 9 of 32 communes in Ba Vi District, Ha Tay Province, northern Vietnam. The results from this study indicate that there were regional differences in relation to basic management practices such as effective utilisation of agricultural by-products for feeding and hygiene practices. These can be explained by variation amongst the regions with respect to environmental factors affecting agricultural activities such as constraints on land use and access to water resources. There were also regional differences in the use of governmental support such as agricultural extension services and financial institutions. These can be attributed to proximity of the communities to each of the extension institutions as well as the phased and community-specific approach to the provision of governmental financial support for dairy development.     

Evaluation of biological and economic efficiency of smallholder pig production systems in North Vietnam

This study evaluates smallholder pig production systems in North Vietnam, comparing a semi-intensive system near a town with good market access, where a Vietnamese improved breed has replaced the indigenous pig breed, and an extensive system away from town, where the indigenous breed still prevails. Fieldwork was conducted in 64 households in four villages. Repeated farm visits yielded 234 structured interviews. Data were analysed by linear models and non-parametric tests. Production inputs and outputs were quantified, and feed use efficiency and economic efficiency were assessed. The gross margin was higher for semi-intensive production with the improved breed, while the benefit–cost ratio was higher under extensive conditions with the indigenous breed. The net benefit did not differ between systems. Twenty-four per cent of farmers yielded a negative net benefit. In one village under extensive conditions, live weight output from indigenous sows with crossbred offspring compared positively with the output from semi-intensive production with improved genotypes, but was associated with high inputs, making production inefficient. Results indicate that improved genotypes might not be an efficient production alternative for saving-oriented production with limited resource supply. Suitability of evaluation parameters, farmers’ production aims, and factors impacting the production success in different systems are discussed.     

Screening of Aflatoxins and Zearalenone in feedstuffs and complete feeds for pigs in Southern Vietnam

A survey ofaflatoxins and zearalenone (ZEA) in 120 samples, including cassava chip (12), maize (12), rice bran (24), broken rice (24), and complete feeds for growing pigs (24) and sows (24) was carried out in southern Vietnam. Aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) were determined by an HPLC method using an immunoaffinity column for clean-up. Zearalenone was analysed by Enzyme-Linked Immunosorbent Assay (ELISA) AgraQuant. High incidences of aflatoxins and ZEA in feedstuffs and pig feeds (83.3%-100%) were detected. Aflatoxins and ZEA were detected in all commodities analyzed. Aflatoxin B1 was found in 100, 92, 92, 83, 100 and 96%, respectively, of samples of cassava chip, maize, rice bran, broken rice, and complete feeds for growing pigs and sows, with mean concentrations of 0.86, 77.5, 1.3, 1.6, 4.7 and 7.5 microg/kg, respectively. AFB2 and AFG1 were found in low concentrations and co-occurred with AFB1 in all samples where they were found. ZEA was detected in 8%, 33%, 36%, 21%, 67% and 67%, respectively, of the samples of cassava chip, maize, rice bran, broken rice, and complete feeds for growing pigs and sows, with average concentrations of 10.0, 163.5, 83.1, 31.4, 86.0 and 101.4 microg/kg, respectively. The high incidence of mycotoxins found in feedstuffs highlights the need for periodic monitoring and prevention ofmycotoxins, not only in feeds, but also in food for human consumption.     

越南马铃薯晚疫病的研究概况

晚疫病是越南马铃薯上最重要的病害。各马铃薯产区均有发生。在江河三角洲地区晚疫病的发生通常比较晚，从12月下旬即第二个生长季后半期开始发病，在1月至2月气温较低、湿度较大时，晚疫病常常严重流行。在Sapa地区（北京高原），整个生长晚疫病对马铃薯作物都是主要威胁。在感病品种上病害的发生和严重度可达到100％。在大叨地区，在干旱季节（11－4月）晚疫病发生最轻，而在雨季（5－10月）严重流行。在越南，还未进行晚疫病菌生物学和流行学方面的基础研究。对晚疫病防治研究主要集中在筛选新的杀菌剂。大部分工作集中在抗病育种和抗病品种的筛选。目前需要进行晚疫综合治疗、流行学、晚疫病菌生物学和抗病育方面的深入研究和培训。     

Rural income generation through improving crop-based pig production systems in Vietnam: Diagnostics,interventions, and dissemination

Sweetpotato-pig production is an important system that generates income, utilizes unmarketable crops, and provides manure for soil fertility maintenance. This system is widely practiced from Asia to Africa, with many local variations. Within this system, pigs are generally fed a low nutrient-dense diet, yielding low growth rates and low economic efficiency. Our project in Vietnam went through a process of situation analysis, participatory technology development (PTD), and scaling up over a seven-year period to improve sweetpotato-pig production and to disseminate developed technologies. The situation analysis included a series of pig production assessments in several provinces in northern and southern Vietnam, and pig supply-market chain identification was conducted in 13 provinces. The analysis of these studies informed the project of the following: (1) appropriate locations for our activities; (2) seasonal available feedstuff and farmers feeding practices; (3) market fluctuation and requirements; and (4) feeding and management improvement needs based on which the subsequent phase of PTD was designed. The PTD involved a limited number of farmers participating in sweetpotato varietal selection, sweetpotato root and vine silage processing, seasonal feeding combination, and pig feeding with balanced crop-feed diet and silage. Six years of multi-location and multi-season sweetpotato selection resulted in a few promising varieties that yielded up to 75% more dry matter and have since been formally released. The most significant results of silage processing and feeding trials include improved growth, higher feeding efficiency, increased year-round local feedstuff, and considerable labor reduction from eliminated cooking and vine cutting. Once these technologies were developed, a farmer-to-farmer training model was designed for scaling up the adoption and impact. Farmer trainers from seven communes in seven provinces received training in these technologies. In turn, they undertook the responsibility of training other farmers on sweetpotato selection, processing, and feeding. An impact study was also administered to monitor and evaluate (M&E) the dissemination process and to document the impact of the new technologies and farmer-to-farmer training model on pig growth and farmer income generation. The results showed that both participating and non-participating farmers have taken up the technologies, although the former demonstrates higher rates of adoption than the latter. The participants also generated more income and saved more labor from the adoption of the technologies. While the scaling up and M&E activities are on-going, the project has since broadened from a sweetpotato-pig system perspective to a pig-cropfeed system perspective based on farmers needs. It has included other crop feeds such as cassava and peanut stems in the research portfolio. New technologies based on on-going PTD will continuously be incorporated into the future training curriculum.Dai Peters is currently a senior scientist with the International Center for Tropical Agriculture (CIAT) based in Hanoi, Vietnam. This publication is based on research conducted while she was a research scientist with the International Potato Center (CIP). She holds a PhD from North Carolina State University. Her research interests include on-farm participatory research methodologies, agroenterprise development, and sweetpotato-pig farming systems in Vietnam and Papua, Indonesia. Her recent publications include a manual on crop-based pig feed systems, post-harvest fermentation of sweetpotato roots and vines, and agroenterprise development.Nguyen Thi Tinh is currently a coordinator of the sweetpotato-pig improvement project at the International Potato Center in Vietnam. Ms. Tinh holds a Masters degree in animal nutrition from Wageningen University, Netherlands. She participated in the project on pig feeding trials for five years.Mai Thach Hoanh is a sweetpotato breeder with the Root Crop Research Center of Vietnam Agricultural Science Institute (VASI). He holds a PhD in sweetpotato breeding from the same institute. He participated in the project for seven years on sweetpotato selection. Nguyen The Yen is a crop scientist in the Food Crop Research Institute of Vietnam. He holds a PhD in sweetpotato breeding from VASI. He participated in the project for five years on sweetpotato selection.Pham Ngoc Thach is a lecturer with the Hanoi Agricultural University. He holds a PhD in veterinarian science from the same university. He participated in the project for five years in controlling pig diseases during the feeding trials.Keith Fuglie is a regional coordinator and research scientist in the International Potato Center based at Bogor, Indonesia. He holds a PhD in agriculture economics from the University of Wisconsin. He designed the impact study for the project.     

Transforming the ``model' approach to upland rural development in Vietnam

Three quarters of Vietnam'sland area is in the uplands and foothills,which contain some of the poorest communes inthe country. The Ngoc Lac Natural ResourcesConservation and Management Project, in ThanhHoa Province, is one of several large uplandrural development projects that receivessubstantial funding from foreign governments inVietnam. The project was designed in 1995 toaddress the environmental constraints tosocio-economic development of Ngoc LacDistrict, while improving agriculturalproduction and natural resources management.During the first three years of operation, theproject focused on the introduction anddissemination of various ``model' technologicalpackages for improved agriculture, forestry,and animal husbandry. These models includedtree nurseries, sloping agricultural landtechnologies, integrated fish pond-livestockpen-home garden systems, and several animalhusbandry activities. However, the distributionof the models was not socially equitable, thesustainability of the models by model farminghouseholds proved problematic, and the adoptionof these technology practices by non-modelhouseholds was quite low. Four lessons can beidentified from past rural developmentexperience: beware of ``participatory' ruralappraisal, start small and go slowly, introducelimited technologies, and help farmers adaptthe technologies. There are two promisinginitiatives underway in Vietnam. These are theparticipatory curriculum development and theparticipatory technology developmentinitiatives of the Social Forestry SupportProgram.     

越南和泰国水稻产量预报研究

应用全球海温月平均温度和500hPa月平均高度格点资料，分析越南和泰国水稻产量与海温变化和环流变化的关系，采用11种不同的统计方法对趋势产量进行处理，经相关普查，运用逐步回归方法建立了不同气象产量序列与海温、环流回归模型．经统计检验，越南、泰国通过生长曲线方法处理的趋势产量和气象产量，回归效果较好．在分析回归模型物理意义的基础上，对2002年的产量进行了试报检验，误差仅2％～5％，说明可以在实践中应用．     

稻文化的再思考3:稻与社稷——印度、泰国等东南亚、南亚主要国家

东南亚、南亚地区是世界上重要的稻米产区,稻米在民众饮食生活和国家社会政治中占有重要地位,民众生活中也保存了非常悠久和丰富的稻作文化习俗及稻谷起源神话传说。本文分析了水稻在东南亚、南亚主要国家印度、印度尼西亚、泰国、越南、菲律宾、孟加拉国、缅甸的作用、地位、生产、消费、文化等情况,并指出了印度、印度尼西亚稻文化的主要标志。