Analysis of the risk of introduction and spread of porcine reproductive and respiratory syndrome virus through importation of raw pigmeat into New Zealand

AIMS: To determine the frequency with which porcine reproductive and respiratory syndrome (PRRS) virus (PRRSv) would become established in a non-commercial pig herd in New Zealand due to illegal feeding of uncooked food waste containing virus-contaminated pigmeat. To determine the likelihood of a single incursion resulting in a multi-farm outbreak of the disease, and describe the spatio-temporal characteristics of such an outbreak.

METHODS: A Monte Carlo simulation model was constructed to determine the expected annual frequency of PRRSv infection being initiated in a non-commercial pig herd as a result of inadvertent feeding of pigmeat imported from countries endemically infected with the disease. Once the likelihood of PRRSv becoming established in a single pig herd was determined, stochastic spatially explicit infectious disease modelling software was utilised to model the temporal and spatial characteristics of the resulting epidemic.

RESULTS: Assuming the proportion of imported pigmeat remained at current levels, consumption patterns of pigmeat in households in New Zealand remained steady, and limited compliance with recently reintroduced regulations to prevent feeding of uncooked food waste, at least 4.3 pig herds per year were predicted to become infected with PRRSv. Simulation modelling of PRRSv epidemics related to initial infection of a non-commercial farm produced an estimate that 36% of these incursions would spread from the initial herd, and that these outbreaks would involve 93 herds on average in the first year. By increasing the estimated persistence of PRRSv infection in small herds, an average of 205 herds became infected in the first year.

CONCLUSIONS: Given a mean of 4.3 infected premises per year and a 36% probability of infection spreading beyond the initial infected herd, there was a 95% likelihood of a multi-farm PRRS outbreak occurring within 3 years.

CLINICAL RELEVANCE: Introduction of PRRSv through importation of virus-contaminated pigmeat presents a high risk for establishment of the disease in the pig industry in New Zealand.     

Sow performance and maternal behaviour in organic and conventional herds

Abstract

The study evaluates the first three parities of 144 Swedish Landrace×Yorkshire sows from three certified organic and three conventional commercial piglet-producing herds. Sows and litters were weaned at seven and five weeks post partum (pp) in organic and conventional herds, respectively. Herdsmen judged sow behaviour and maternal ability at farrowing, two weeks pp and at weaning. Herdsmen collected registrations of litter size, litter weight and sow fat status at farrowing and at weaning. Piglet mortality and oestrous signs were registered continuously during the nursing period. Sows in organic herds were scored to be more cautious among piglets, and to have better nursing behaviour and maternal ability in early lactation than sows in conventional herds. Piglet mortality was higher in organic than in conventional herds. Oestrus during lactation was only observed among sows in organic herds, and sows showing oestrus during lactation were fatter at weaning.     

培育大学生就业能力途径探析

指出了大学生就业问题日益成为社会关注的热点和难点问题,培育大学生就业能力具有重要的价值意义,采用要素分析的方法全面解析了大学生就业能力的内涵及影响因素,进而从个人、学校、社会三个层面提出了培育大学生的就业能力应采取的措施。     

茶菜、茶点心在旅游文化中的应用

本文从茶菜、茶点心的历史文化背景出发,结合目前餐饮、茶楼的经营现状与茶菜、茶点心的保健作用,融合地方特色与文化元素,倡导茶宴、茶菜、茶点心在旅游文化中的应用。引领消费新潮流,使之成为一道新的旅游文化风情线。     

Combining Ability in the Rice Lines Selected for Direct-Seeding in Flooded Paddy Field

Summary

To estimate the general and specific combining ability for direct seeding in flooded paddy field, we completed a 4 × 3 factorial crossing (design II) in 1998, and evaluated the 12 F¹ hybrids and their 7 parents, including selected lines for yield, yield components and culm traits in 1999. Generally, parents with good combining ability produce good lines in later generations. Therefore, the basic information about the general combining ability (GGA) and specific combining ability (SGA) is valuable for breeding cultivars. The effect of GGA was significant for culm length, culm thickness, panicle length, 1000-grain weight and grain yield, which indicated the importance of the additive effects of the genes for these traits. The effects of dominant genes were significant for culm length, culm thickness and grain yield, indicating that these traits were also controlled by nonadditive gene actions. Mid-parent heterosis ranged from -16.3% to 37% with an average value of 17.3% for grain yield, and from -1.7% to 30.0% with an average value of 13% for culm length, and from -6.1% to 23.9% with an average value of 4.2% for culm thickness. Some parents with positive GCA for yield, culm thickness and panicle length were identified. They would be useful for developing cultivars adapted to direct-seeding in flooded paddy fields.     

Agroforestry Systems for Food and Nutrition Security–Potentials,Pathways and Policy Research Needs

SUMMARY

Food insecurity and malnutrition continue to be the most daunting development challenges in most developing countries. Increases in the productivity of cereal grain crops have helped many developing countries achieve self-sufficiency in meeting the energy requirements, but malnutrition still exist. Agroforestry–growing useful tree crops with annual crops–could provide a solution to food security micronutrient malnutrition. The paper develops a conceptual framework for identifying pathways of how agroforestry systems can contribute to nutrition security and its potential as a food-based nutrition intervention. Furthermore, a theoretical framework for studying the interactions of agroforestry and nutrition security is developed. Finally, policy implications and research needs are identified.     

罐藏食品腐败变质的原因及对策

罐头食品在生产过程中,经常会出现一些如胀罐、酸败、硫化黑变、霉变等腐败变质现象。该文分析了罐藏食品腐败变质的原因,并提出解决对策。     

柞蚕丝素解酒保肝功能食品解酒防醉作用的研究

为了解柞蚕丝素解酒保肝功能食品的解酒防醉效果,进行了小鼠防醉和解酒试验,观察柞蚕丝素解酒保肝功能食品对小鼠醉酒时间和睡眠时间的影响。结果表明：柞蚕丝素解酒保肝功能食品可显著延长小鼠对酒精的耐受时间,缩短醉酒的持续时间。     

粮食丰产科技工程对小麦全要素生产效率的影响——基于DEA-Malmquist方法

基于DEA-Malmquist方法对粮食丰产科技工程实施以来中国小麦全要素生产率(TFP)的变化进行分析.研究表明,该政策的实施显著促进了中国小麦产业全要素生产率的增长,华北地区已经成为中国小麦生产的优势地区.粮食丰产科技工程战略的实施已显成效,相关地区应利用发展时机不断提高生产技术和生产效率,确保中国小麦产业持久发展以保障粮食安全.     

呋喃西林代谢物酶联免疫检测方法的建立

[目的]建立动物性食品中呋喃西林代谢物ELISA检测方法。[方法]通过制备特异性强的单克隆抗体,采用间接竞争ELISA法建立动物性食品中呋喃西林代谢物ELISA检测方法,并研制出对动物性食品中呋喃西林代谢物残留检测的试剂盒。[结果]该试剂盒标准曲线的IC50值为0.267 7μg/L,最低检测限为0.1μg/kg,样本加标回收率范围为79.5%～95.6%,变异系数为7.6%～9.7%。在交叉反应试验中,对呋喃西林的交叉反应率为25%,与其他药物的交叉反应率均小于1%,表明该方法具有很强的特异性。[结论]该方法灵敏度、准确度、精密度均较高,能满足兽药残留的检测要求,且检测时间短(45 min),样本前处理简单、检测成本低,适合于大量样本中呋喃西林代谢物残留检测的快速筛选。