Risk-based surveillance of antimicrobial residues in pigs – Identification of potential risk indicators

Around 20,000 samples are analysed each year for the presence of antibacterial residues in Danish finisher pigs, and between zero and five samples are detected positive above the maximum residue level (MRL). The intention was to develop a risk-based surveillance programme involving fewer samples while ensuring equal sensitivity. Therefore, risk indicators were searched for. Data were obtained from the Danish slaughterhouse database covering the period from July 2010 to December 2012. Residues were found or suspected in 17 incidents. In nine of these, the farmer had called in to prevent the pigs from being slaughtered. Hence, eight suspect cases were found through the surveillance programme, and two of these were above MRL. For these eight case herds, the number of pigs slaughtered and the number in which each of the following lesions were found were included in a statistical analysis: chronic pleuritis, tail bite, chronic pericarditis, chronic pneumonia, chronic peritonitis, osteomyelitis, abscess in hindquarters, abscess in leg/toe and abscess in forequarters. Only chronic pleuritis was associated with the presence of residues. Next, data from all herds delivering pigs for slaughter to the same abattoir were included covering a 3-month period prior to the residue finding. The prevalence of chronic pleuritis was on average 1.7 times higher in the eight case herds compared to all other herds. In two herds, the prevalence was significantly higher (P ≤ 0.05), and in one herd substantially higher, but only borderline significant (P = 0.1). In the remaining herds, the prevalence did not differ from the other herds delivering pigs to the abattoir. This indicates that chronic pleuritis might be considered as a risk indicator for use in surveillance. Other risk indicators/factors – reported in the cases where the farmers called in – were inadequate marking of treated animals and incorrect use of medication dispensers. These factors are not suited for use in surveillance and should be dealt with otherwise.     

中国农作物长势遥感监测研究综述

农作物长势监测的目的是为早期估产提供依据,同时为田间管理提供及时的信息。笔者总结了中国农作物长势监测的研究进展、研究方法,指出用于长势监测的遥感数据空间分辨率较低,常用的监测指标具有局限性,监测精度有待提高。“3S”技术的集成发展,进一步实现一体化应用于该领域仍是今后的发展方向。随着农作物长势运行化监测系统的进一步完善,对田间管理的诊断需求会日益加剧,因此作物长势的诊断将成为今后的研究重点。     

Development of an integrated pest management programme for cotton. Part 2: Integration of a lucerne/cotton interplant system,food supplement sprays with biological and synthetic insecticides

Part 1 of the paper showed that the integration of a lucerne/ cotton interplant system with supplementary food sprays retained and increased populations of predatory insects in the cotton crop. The strategic use of biopesticides (Bacillus thuringiensis (Bt), nuclear polyhedrosis virus (NPV)) reduced the use of synthetic insecticides by 50% without sacrificing cotton yield and profitability. In economic terms, the average gross margin for the IPM plot was A$3255 compared with A$3020 and A$3218 for the plots treated with (1) conventional insecticides on transgenic (Ingard®) cotton and (2) conventional insecticides on non-transgenic cotton. The use of transgenic cotton affected a 25% saving on synthetic insecticide usage. The results clearly indicate that a refined IPM approach could have a distinctive advantages in terms of economic and environmental impacts on cotton production. The success of such an approach lies in a strict adherence to its methodology.     

Host factors associated with the detection of Aeromonas salmonicida and Yersinia ruckeri in Ontario, Canada government fish hatcheries

This paper presents an epidemiological investigation of Ontario Ministry of Natural Resources Fish Health Laboratory data from 1981 to 1997, to determine whether fish species and age were associated with lot-level detection of Aeromonas salmonicida and Yersinia ruckeri in hatchery fish. In stepwise logistic regression, the species brook trout and back-cross (lake trout crossed with the hybrid “splake”) were more likely to test A. salmonicida-positive compared to all other species reared in the hatcheries. Similarly, the species brook trout was significantly more likely to test Y. ruckeri-positive compared to all other species. For both pathogens, the 1–5-month age group was associated significantly with detection. These findings suggest that purposive sampling of higher-risk fish lots could increase the likelihood of detecting both study pathogens.     

Landscape improvement, or ongoing degradation – reconciling apparent contradictions from the arid rangelands of Western Australia

Recent quantitative site-based monitoring and qualitative aerial and ground traverses provide contrasting assessments of the health of much of the arid shrublands of Western Australia extensively grazed by livestock (‘rangelands’). Although these results seem incompatible, we explain the apparent contradictions based on landscape succession processes operating at multiple levels of ecological organisation. Specifically, we suggest that the intact areas in which site-based monitoring is conducted are contracting as catchment canalisation and desiccation increase. However, the impacts of these processes have not yet become manifest at the site scale. The site-based system addresses important regional questions. These relate to the large, relatively intact areas away from most active surface flows, which should be a focus for resource conservation, given practical limits to repairing widespread degradation with low management inputs. We provide a complementary set of questions to provide a more comprehensive audit of rangeland dynamics in the context of underlying hierarchical landscape patterns and processes that might threaten intact areas. We recognise the need to match questions and levels of ecological organisation and the implications these have for sampling. We also recognise the difficulty in producing concise statements of change for clients when reporting on complex ecological issues and processes. Without a clearly articulated, and well understood, hierarchical model of pattern and process within which apparently contradictory findings can be reported meaningfully, policy makers may be confused by the results, with the consequent risk of policy inaction.     

降低仔狐早期死亡率的研究

仔狐早期（５日龄内）的死亡率最高,占哺乳期死亡数的４７％;占仔狐、育成狐死亡总数的４１％。本研究对北极狐初产雌狐实行短期环境监控,同时进行恢复或强化母性的调驯,连续５年产仔雌狐的母性行为正常,有效地扼制了仔狐的早期死亡,５日龄内仔狐的成活率平均达９８６８％,比对照组高２１６５％。     

浙江省黄坛口水库饮用水取水口水质监测和分析

根据浙江省黄坛口水库饮用水取水口水质监测数据,对其水质情况进行了分析。结果表明,不同水深总氮含量升降次序基本一致,均在1、2月份达到最低值;不同水深粪大肠菌群与月份的变化关系无明显规律;不同深度的水质pH变化趋势基本一致,在9月份出现1个低点,在3月份达到最高点;不同水深的溶解氧含量成规律性变化,2月份、8月份分别出现1个拐点,其中8月份的拐点最大,含量也最低;不同深度的高锰酸盐指数变化趋势一致,均是在3月份最低,7月份出现1个小高点,9月份出现1个低点,均超过1.0 mg/L;不同水深的化学需氧量6月份最大,水下5 m稍高;生化需氧量基本在7月份最高,4月份最低,年初和年末数值也都较低;不同水深氨氮含量与月份的变化关系趋势基本一致,均在6月份达到最高。认为水下各分层水质稳定,均适宜作为取水点的取样深度。     

农业干旱遥感监测方法及其应用的研究进展

从可见光-近红外遥感监测法、热红外监测法、可见光-近红外-热红外遥感监测法、高光谱遥感监测法、微波遥感监测法等方面对国内外农业干旱遥感监测方法及其应用的研究进展进行了综述,以期促进今后农业遥感干旱监测的深入研究。