Evaluation of protection conferred by a Salmonella Typhimurium inactivated vaccine in Salmonella-infected finishing pig farms

The efficacy of an inactivated S. Typhimurium vaccine administered to pigs at the beginning of the fattening period was evaluated in four clinical trials (trials A, B, C and D). Faecal shedding and the systemic antibody response during fattening, as well as, the cecal contents and mesenteric lymph nodes collected after slaughtering were used to assess the outcome. Salmonella shedders prevalence in the control groups was six times higher than in the treated groups in trials A and D, both herds infected by S. Typhimurium. The risk of positive pens was also four or five times higher for the pens housing control pigs in trials A and C. Lower prevalence of Salmonella was observed in the slaughter samples from the vaccinated pigs in trial D and in the cecal content samples in trial A, when just the S. Typhimurium results were compared. The results suggest the effective homologous protection of the vaccinated pigs; however, the high humoral response elicited in the vaccinated pigs complicates their use in farms under serological surveillance programmes.     

湖北黄袍林场喜树木本资源及应用

喜树是我国特有的珍贵树种,其次生代谢物因含有一种重要生物碱而闻名。为了宣传这种珍贵喜树资源及推广应用,以湖北国营通城县黄袍林场为对象,简要介绍了黄袍林场喜树的木本资源生长特征、种子园、育苗及推广应用情况。希望引起政府部门和科研人员的重视和研究,提高对这种国家Ⅱ级保护植物的保护及推广应用。     

The positive relationship between soil quality and crop production: A case study on the effect of farm compost application

In order to ensure sustainable agriculture, and for evaluating the effects of management practices on soil processes, tools for assessing soil quality are required. The development and use of a multiparameter index, which includes a wide range of soil properties, have been tested and found useful by several studies. However, soil quality measurements are ‘stand-alone’ tools unless they are either linked to important soil functions, used to characterize (agro)ecosystems or used to predict sustainability or productivity. In our study, the relationship between crop production and soil quality was assessed in a six year old field experiment studying the effect of farm compost (FC) amendment in a crop rotation of potato, fodder beet, forage maize and Brussels sprouts. To justify the hypothesis that repeated FC amendment results in both improved soil quality and consequently higher crop yields, a wide range of chemical, biological and physical soil properties were measured and integrated into a soil quality index (SQI). Next, crop yields were used as a functional goal to verify the causal relationship between SQI and crop production. Our results showed that there were significant changes in chemical, physical and biological soil quality as a result of repeated FC amendment. This was evidenced for example by a remarkable increase in both soil organic carbon (SOC) and total N content. Microbial biomass, the relative amount of bacterivorous nematodes and earthworm number were significantly increased as well and, together with SOC and total N, indicated as the dominant factors in assessing soil quality. The integration of these key indicators into the SQI revealed higher SQI values when FC was applied. In addition, crop yields were increased in all FC treated plots by which SOC was pointed out as the most important indicator influencing crop production. Finally, a causal relationship was observed between soil quality and the yield of potato and fodder beet. We conclude that our SQI may be a promising and useful tool to compare different (soil) management practices in relation to a strategic, regional goal, e.g., sustainable high yields. Before generalizing, we recommend a thorough validation of our SQI in other long-term field experiments.     

Do labour productivity and preferences about work load distribution affect reproduction management and performance in pig farms

Increases in labour productivity are essential factors, as well as technical effectiveness, for the competitiveness of pig farming. However, the preferences of farmers for controlled (i.e. limited) daily working hours or available days for vacation also increase. The objective of this study was to explore how these preferences about work might be associated to specific combinations of practices or affect performance. The study was carried out by direct investigation of the stockbreeders. Data analysis used factorial analysis to identify relationships between practices, labour productivity, sow productivity and work load distribution. Results showed independence between sow productivity and labour productivity. Three independent types of preferences about work load distribution were identified: the limitation of density of daily work, the avoidance of insemination activities during the weekend and the avoidance of farrowing supervision during the weekend. These preferences about work load distribution were mainly related to weaning, oestrus detection and insemination techniques. A relationship was also seen between farrowing and cross-fostering techniques, and labour and sow productivity. Results suggest that preferences about work load distribution influence the choice of reproduction practices without influencing performance. Finally, concerning the labour productivity, it was linked with some specific techniques at farrowing but the results also indicated that it was mainly related to the size of farrowing batches.     

Population history and genetic variability in the Spanish Arab Horse assessed via pedigree analysis

The important role of values is very evident when it comes to citizens' concept of sustainability. The present paper had the objective to define sustainability as a socio-cultural concept for livestock production systems. The main research question was: how do Dutch citizens value various aspects of dairy production systems? We conducted farm visits with citizens panels in The Netherlands. We asked citizens about their on-farm perception (smelling, hearing, seeing and feeling) and what they perceived valuable to preserve for the future. We presented sustainability as a socio-cultural concept which included citizens' valuable aspects (SCA) and concerns (SCI). We defined a socio-cultural aspect (SCA) as an aspect of a livestock production system which is mentioned by society as being valuable to preserve for the future. We identified an SCA as a socio-cultural issue (SCI) when it evokes societal concern in present time or is expected to do so in the future. By qualitative analysis we identified SCAs and SCIs of dairy production systems and combined these into socio-cultural themes (SCT). We found ten socio-cultural themes which contained 42 socio-cultural aspects (SCA), of which 27 were identified as socio-cultural issues (SCI). We can conclude that that livestock production systems have more values for society than solely food production, because only one of the ten identified socio-cultural themes directly concerned food production (SCT 1), whereas the nine other themes concerned values that go beyond food production: farming activities (SCT 2), farm income (SCT 3), animals (SCT 4), landscape (SCT 5), nature (SCT 6), environment (SCT 7), farming culture (SCT 8), national culture (SCT 9) and services for society (SCT 10). One of the main values of agriculture seems the combination of apparently contradicting aspects such as technology and nature within one system. In conclusion, sustainability as a socio-cultural concept for livestock production systems is defined by a wide range of socio-cultural aspects and issues, reflecting citizens' values and concerns of that system and for a sustainable agriculture it is important that both SCIs and SCAs are taken into account.     

Oxidants and antioxidants in disease: oxidative stress in farm animals

Important infectious diseases in farm animals, such as pneumonia and enteritis, are thought to be associated with the so-called oxidative stress, i.e. a chemical phenomenon involving an imbalance in the redox status of the individual animal. The specifics of oxidative stress and how it may result in disease or be prevented are complex questions with no simple answers. However, the considerable literature on the subject suggests that many researchers consider oxidative stress-related mechanisms to be important early events in disease development. A particularly intriguing aspect is that, at least theoretically, oxidative stress should be easily prevented with antioxidants yet the use of antioxidants as therapy remains controversial. The present knowledge on oxidative stress in farm animals is the topic of this review.     

Mapping hotspots of multiple landscape functions: a case study on farmland afforestation in Scotland

Many conservation and restoration efforts in developed countries are increasingly based on the premise of recognising and stimulating more ‘multi-functionality’ in agricultural landscapes. Public policy making is often a pragmatic process that involves efforts to negotiate trade-offs between the potentially conflicting demands of various stakeholders. Conservationists’ efforts to influence policy making, can therefore benefit from any tool that will help them to identify other socio-economic functions or values that coincide with good ecological conservation options. Various types of socio-economic objectives have in recent years been mapped across landscapes and so there are now important opportunities to explore the spatial heterogeneity of these diverse functions across the wider landscape in search of potential spatial synergies, i.e. ‘multiple win locations’ or multifunctional ‘hotspots’. This paper explores the potential occurrence of such synergies within the agricultural landscape of northeast Scotland and evaluates an existing woodland planting policy using and combining three different policy objectives. Our results show that there are indeed broad areas of the studied landscape where multiple objectives (biodiversity, visual amenity and on-site recreation potential) could be achieved simultaneously (hotspots), and that the case study which we evaluate (the Farm Woodland Premium Scheme) could be much better spatially targeted with regards to each individual objective as well as with regards to these hotspots of multifunctionality.

What is so disturbing about Jan Smiley's A Thousand Acres?

Jane Smiley's award winning and disturbing novel, A Thousand Acres, invites a critical appraisal of a popular assumption for proponents of sustainable agriculture: that family farming and sustainable agriculture are (at least indirectly) mutually reinforcing. This process begins with a plot that presents an Iowa multigenerational farm family headed by an acutely dominant father. Consequences of this dominance include subjugation of everyone involved with the farming operation, varieties of abuse of the daughters, and primitive non-environmental farming. Also in the novel three structural components of the family farm/rural setting aggravate the nightmarish situation: multigenerational participation in one farming operation, children remaining on the farm, uninterrupted, into adulthood, and the power of community appearances. It is argued that these components contribute not only to the family problems, but also to making the poor farming that emerges in this family not very coincidental. This analysis, if correct, raises many issues about farm structure and farming practices. They include how the younger generation(s) of family farm structures cope with their situations, whether aspects of family farms skew who decides to remain to farm, family farm ownership and transfer structure, how well farmers understand their own farms, and the case for voluntarism regarding environmental issues in farming. One theme throughout the essay is that the novel enables better recognition and appreciation of the subtle relationship between family problems and farming practices.     

农用运输车可靠性分析评价研究

以ＹＬ２２０８ＣＷ型四轮农用运输车可靠性试验为依据,参照有关的国家和前机械工业部标准,对该车可靠性进行了分析,计算和评价,并开发了农用运输车可靠性评价计算机系统,提出了提高和改进其可靠性的途径。     

Optimal on-farm irrigation scheduling with a seasonal water limit using simulated annealing

As water resources are limited and the demand for agricultural products increases, it becomes increasingly important to use irrigation water optimally. At a farm scale, farmer's have a particularly strong incentive to optimize their irrigation water use when the volume of water available over a season is production limiting. In this situation, a farmer's goal is to maximize farm profit, by adjusting when and where irrigation water is used. However, making the very best decisions about when and where to irrigate is not easy, since these daily decisions require consideration of the entire remaining irrigation season. Future rainfall uncertainty further complicates decisions on when and which crops should be subjected to water stress. This paper presents an innovative on-farm irrigation scheduling decision support method called the Canterbury irrigation scheduler (CIS) that is suitable when seasonal water availability is limited. Previous optimal scheduling methods generally use stochastic dynamic programming, which requires over-simplistic plant models, limiting their practical usefulness. The CIS method improves on previous methods because it accommodates realistic plant models. Future farm profit (the objective function) is calculated using a time-series simulation model of the farm. Different irrigation management strategies are tested using the farm simulation model. The irrigation strategies are defined by a set of decision variables, and the decision variables are optimized using simulated annealing. The result of this optimization is an irrigation strategy that maximizes the expected future farm profit. This process is repeated several times during the irrigation season using the CIS method, and the optimal irrigation strategy is modified and improved using updated climate and soil moisture information. The ability of the CIS method to produce near optimal decisions was demonstrated by a comparison to previous stochastic dynamic programming schedulers. A second case study shows the CIS method can incorporate more realistic farm models than is possible when using stochastic dynamic programming. This case study used the FarmWi$e/APSIM model developed by CSIRO, Australia. Results show that when seasonal water limit is the primary constraint on water availability, the CIS could increase pasture yield revenue in Canterbury (New Zealand) in the order of 10%, compared with scheduling irrigation using current state of the art scheduling practice.