Modelling as a tool to redesign livestock farming systems: a literature review

Livestock farming has recently come under close scrutiny, in response especially to environmental issues. Farmers are encouraged to redesign their livestock farming systems in depth to improve their sustainability. Assuming that modelling can be a relevant tool to address such systemic changes, we sought to answer the following question: ‘How can livestock farming systems be modelled to help farmers redesign their whole farming systems?’ To this end, we made a literature review of the models of livestock farming systems published from 2000 to mid-2009 (n = 79). We used an analysis grid based on three considerations: (i) system definition, (ii) the intended use of the model and (iii) the way in which farmers’ decision-making processes were represented and how agricultural experts and farmers were involved in the modelling processes. Consistent rationales in approaches to supporting changes in livestock farming were identified in three different groups of models, covering 83% of the whole set. These could be defined according to (i) the way in which farmers’ decisions were represented and (ii) the model's type of contribution to supporting changes. The first type gathered models that dynamically simulated the system according to different management options; the farmers’ decision-making processes are assumed to consist in choosing certain values for management factors. Such models allow long-term simulations and endorse different disciplinary viewpoints, but the farmers are weakly involved in their design. Models of the second type can indicate the best combination of farm activities under given constraints, provided the farmers’ objectives are profit maximisation. However, when used to support redesigning processes, they address neither how to implement the optimal solution nor its long-term consequences. Models of the third type enable users to dynamically simulate different options for the farming system, the management of which is assumed to be planned according to the farmers’ general objectives. Although more comprehensive, these models do not easily integrate different disciplinary viewpoints and different subsystems, which limits their usefulness as support tools for redesigning processes. Finally, we concluded about what specific requirements should be for modelling approaches if farmers were to be supported in redesigning their whole livestock farming systems using models.     

A method for assessing work productivity and flexibility in livestock farms

Changes affecting livestock farming systems have made farm work a central concern for both the sector and for farmers themselves. Increased pressure on farms to be competitive and productive together with farmers' demand for greater autonomy, holidays or time to spend on private activities and the family converge to underline the two key dimensions of work - productivity and flexibility - required for the assessment of work organization. This paper proposes a method called the QuaeWork (QUAlification and Evaluation of Work in livestock farms) to assess work productivity and flexibility on a farm, and its use to identify how livestock management can contribute to work organization on dairy farms. The QuaeWork method was set up through an iterative process combining surveys conducted with farmers in two regions of France, discussions with different experts and literature review. The QuaeWork was applied on a sample of seven dairy farms in the southern Massif Central in France to identify patterns of how livestock management contributes to work organization. The QuaeWork was used to analyse work organization over the year through a systemic approach to the farm, integrating interactions between herd and land management, workforce composition, equipment facilities and combinations of activities through a characterization of 'who does what, when and for how long'. The criteria for assessing work productivity were work duration (routine work, seasonal work) and work efficiency (per livestock unit or hectare of utilized agricultural area). The criteria for assessing work flexibility were room for manoeuvre and adjustments to internal and external events. The three main patterns of livestock management practices to work organization were identified. In pattern-1, farmers used indoor stable feeding practices with delegated work, with moderate room for manoeuvre and efficiency. In pattern-3, farmers used simplified milking, reproduction and breeding practices to seasonalize work and make it efficient with consistent room for manoeuvre. The method suggests social sustainability criteria to assess work productivity and flexibility, which are important for making reasoned decisions on livestock farm changes, especially innovations. Researchers could usefully exploit the QuaeWork to integrate work objectives (productivity, flexibility) into technical and economic goals.     

Social referents for dairy farmers: who dairy farmers consult when making management decisions

Social referents provide information that aid in farmer decision making. Some social referents, such as veterinarians, have been well studied in the context of dairy farms, but others have not and the role of social referents may change across management practices. This study aimed to understand (1) who farmers consult when making management decisions across different animal care practices and (2) what characteristics of these social referents influence farmer decision making. Secondary thematic analysis was used on two qualitative datasets with dairy farmers from the lower Fraser Valley region of British Columbia, Canada. The two datasets included non-naturalistic data (i.e. interviews, participatory discussion groups) investigating two dairy farm management practices (calf care and transition period management). Analysis revealed four themes: (1) who farmers consult when making management decisions across practices and the role of these social referents, (2) personal and professional characteristics, and the diversity of opinions of social referents, (3) actions of social referents, and (4) the strength of the relationship between the social referent and farmer. Similarities were found across practices regarding the personal and professional characteristics of social referents, even though the role of these referents varied across contexts. Farmers valued diverse opinions and actions that social referents could provide, such as the provision of resources, recommendations, and interpretation of farm data. We recommend future research focused on strengthening the relationship between farmers and social referents.     

Understanding beef-cattle farming management strategies by identifying motivations behind farmers' priorities

This study aimed to identify and better understand management strategies that help livestock farmers adapt to changes in their production contexts, a fundamental challenge. A total of nine beef-cattle farmers were interviewed three times over 1 year to discuss 13 dimensions of livestock farming (e.g. reproduction, feeding, sales, etc.). Characterisation of management strategies rested on three main factors: (i) ranking of the dimensions according to the degree to which farmers desired to control them, (ii) reasons for the ranking and (iii) management guidelines. Although farmers agreed upon the rank of certain dimensions, such as herd management, they differed on that of others, such as sales and administration/regulations. Four motivation categories were identified: risk, pleasure, efficiency and ability to control the dimension. Three management guidelines were identified, which indicated that farmers managed for future survival of their farms at different scales (animal/herd v. whole-farm), involving different resources (biological v. financial) and based on different animal categories (reproductive cows v. animals sold). These results improve understanding of individual livestock farmers and their current management strategies by integrating the motivations behind their strategies. For this reason, they constitute methodological elements that agricultural advisors can use to provide relevant information to farmers while accommodating differences in farm management.     

The ethnoecology of maize variety management: A case study from Mexico

This paper presents a case study of the relationship between farmers' knowledge of maize varieties and their selection and management of these varieties under conditions of technological change. Research for this paper was done among Spanish-speaking small farmers in an ejidoof central Chiapas, Mexico. This ejido is well integrated into the market, and the use of modem technologies is widespread. This research demonstrates that farmers have an extensive and widely shared knowledge of their maize varieties. This knowledge reflects objective maize characteristics. Variation occurs in the farmers' selection and management of maize varieties, but on average the variation deviates from a random pattern in the direction predicted by the farmers' knowledge base. They have incorporated the technological changes brought about by development into their knowledge base. Farmers maintain maize varieties with contrasting traits, and their knowledge base provides important information about which traits and constraints are important to them.     

Ecological-economic modelling of the conservation of threatened habitats: heather moorland in the Northern Isles of Scotland

This paper describes the results of an ecological-economic modelling exercise of the management of a scarce habitat, namely heather moorland. The Orkney Islands of Scotland are used to illustrate a modelling approach which could be easily applied elsewhere, and to other habitats. We describe the evolution and present condition of heather moorland on Orkney, then quantify the extent of over-grazing (leading to ecological damage) on a spatial basis. This is accomplished using a model of heather utilization and heather productivity. Critical grazing limits are then used as constraints in an economic model of farm production decisions, which enables us to quantify the minimum necessary compensation payments which farmers should be offered to offset income losses due to grazing restrictions. Such a policy is in line with European Union and UK agri-environmental policy, which typically uses payments for income forgone as a means of persuading farmers to protect environmental quality.     

Case-control study to identify risk factors for bovine cysticercosis on farms in Switzerland

Taenia saginata cysticercosis causes financial losses to the beef industry and farmers, and represents a significant source for human infection in many countries. A case-control study was conducted to identify risk factors for bovine cysticercosis on farms in Switzerland. The case group (n=119) consisted of farms with infected cattle identified at slaughter in 2005 and 2006. Infections were confirmed by morphological or molecular diagnosis. The control group (n=66) comprised randomly selected farms with cattle slaughtered in the same period but with no evidence or history of infection. In personal structured interviews with the farmers, information regarding local surroundings and farm management was collected. Logistic regression revealed the following 5 factors as being positively associated with the occurrence of bovine cysticercosis: the presence of a railway line or a car park close to areas grazed by cattle, leisure activities around these areas, use of purchased roughage and organized public activities on farms attracting visitors. This information is considered useful for government authorities to direct control strategies as well as for farmers to take measures tailored to local situations.     

Perceptions and Measurements: The Assessment of Pasture States in a Semi-Arid Area of Namibia

How farmers perceive the state of their pastures is an important component of their management decisions and affects natural resources in arid and semi-arid regions. In an explorative study conducted in the Rehoboth farm area of central Namibia, we addressed the question whether the judgments of commercial farmers on pasture conditions are consistent with a botanical assessment of these pastures based on measurements. The perceptions were inferred from the comparative statements of farmers on the pasture quality of adjacent farm pairs. For the botanical assessment, biomass and plant species frequency counts of the same pastures were used. The results of the statistical analysis show a large agreement between perceived and measured pasture states of corresponding farm pairs, thus pasture quality dimensions perceived by the farmers agreed with the measured pasture quality variables. We also discuss the problems of designing more elaborate studies of this type.     

Settler agriculture and the dynamics of resource allocation in frontier environments

This article attempts to conceptualize the dynamics of resource allocation by colonist farmers under the unique conditions of land abundance and labor scarcity which characterize frontier environments, such as the smallholder agricultural settlement areas in the Amazon basin. In contrast, most previous theoretical literature on household agricultural decision making and land-use change in rural areas considers conditions of high population density and land scarcity, and is not, therefore, adequate for understanding critical land-use changes which may be occurring in frontier regions. This article first discusses the appropriateness and inadequacies of the analytical frameworks commonly used to explain the expansion of settler agriculture into remote forest regions and the unsustainable land-use practices observed in these areas. This review serves as the basis for characterizing resource allocation under the particular conditions of frontier environments. A conceptual advance in the analysis is its consideration of the way institutional/policy factors and farm-level characteristics can interact to produce land-use outcomes. This knowledge is essential to understand not only the social and economic factors affecting present land use and choice of technology, but also those factors influencing farmers' demand for more optimal systems of land use which are consistent with varying agro-ecological potentials, demographic situations, and their own management capacity.     

Population pressure,labor availability,and agricultural disintensification: The decline of farming on Rusinga Island,Kenya

Despite a steady increase in population since the 1930s, farmers on Rusinga Island in Kenya have abandoned many traditional intensive agricultural practices, including the construction of hillside terraces. At the same time, low crop yields have led to a chronic shortage of food on the island. This paper, based on an analysis of archival materials and a detailed agronomic study of the farming system, analyzes the causes of this process of disintensification. Labor scarcity resulting from migrant wage employment and the growing importance of the fishing industry has been a major factor in the decline of agriculture on the island. The loss of soil conservation practices and serious weed infestations have contributed to the collapse of farm productivity. This study highlights the importance of understanding not only the local ecology but also the broader political and economic environment in order to explain farmers' decisions and the process of agricultural change.     

Evaluation of the spatial uncertainty of agro-ecological assessments at the regional scale: The phosphorus indicator in northern Italy

Agro-ecological indicators are simple conceptual models to carry out agro-environmental assessments. Their use requires data that need to be obtained at low cost, frequently avoiding direct measurements. The quality of input data thus may limit the usefulness of the indicators. One source of uncertainty is the spatial interpolation of inputs, used to provide indicator values throughout an area. This paper explores the uncertainty of the inputs, and its effect on the output of one indicator, the phosphorus indicator (IP). The indicator evaluates the appropriateness of phosphorus (P) use by farmers, assigning bad scores to over- and under-fertilization. We evaluated its use for P management in the Sud Milano Agricultural Park (northern Italy). We used data contained in a large database of soil and farm properties as well as crop management information at the cadastral parcel level to calculate IP values. The uncertainty of a single input variable (extractable soil P) was tested to quantify the corresponding uncertainty of the indicator. The results show that the variability of IP is high and within 80% of the analyzed area excessive applications of P fertilizers are made, in particular in animal farms. In most cases, uncertainty is not relevant, as it is either very low, or (if high) it is related to extremely low indicator values: in these cases, the assessment of P management is unaffected by the uncertainty of the indicator. The results show that in this area P fertilizers should be applied at lower doses, or not applied at all. An extension service might help farmers with fertilizer management, reducing resource use, environmental pollution and costs. This study shows that uncertainty analysis is a crucial component of environmental assessments, and that the importance of uncertain input data needs to be evaluated on a case-by-case basis.     

Economics of integrated insect management in stored corn

Insects can cause substantial damage to stored grain. In addition, consumers and therefore food processors are increasingly interested in chemical-free products. Integrated pest management (IPM) may increase farmers' profits while reducing their use of pesticides. This study uses a stochastic dynamic programming framework to model the economics of optimal insect control in corn, Zea mays L., stored on-farm with multiple controls conditional on the biophysical conditions of the grain in the bin. We find that for farmers who have a contract with a food processor, where there are quality premiums, the optimal management strategy depends on monitoring the biophysical conditions of the grain and the time period under consideration. For farmers who deliver to the commodity market, their current practices are optimal.     

Attitudes of European farmers towards GM crop adoption

This article analyses European Union (EU) farmers' attitudes towards adoption of genetically modified crops by identifying and classifying groups of farmers. Cluster analysis provided two groups of farmers allowing us to classify farmers into potential adopters or rejecters of genetically modified herbicide-tolerant (GMHT) crops. Results showed that economic issues such as the guarantee of a higher income and the reduction of weed control costs are the most encouraging reasons for potential adopters and rejecters of GMHT crops. This article also examines how putting in place measures to ensure coexistence between GM and non-GM crops may influence farmers' attitudes towards GMHT crop adoption. Results show that the implementation of a coexistence policy would have a negative impact on farmers' attitudes on adoption and consequently may hamper GMHT adoption in the EU.     

Conflict of Interest Between People and Baboons: Crop Raiding in Uganda

Much has been written about insect damage to standing crops, but an area that has received little attention within agricultural development, conservation, and primatological literature is that of primates and the potential damage they can cause to farmers' fields. This is likely to become an increasingly important issue for people interested in primates, as conservation projects adopt a more integrated approach to take account of local people's perspectives and needs. The aim of this paper is to examine the impact of crop raiding by primates, particularly baboons, on farmers living around the southern edge of the Budongo Forest Reserve, Uganda. I use data gathered during monthly farm surveys and informal discussion groups, along with time budget data, to demonstrate that 1) baboons can cause extensive damage to field crops, such as maize and cassava; 2) proximity of the farm to the forest edge and the presence or absence of neighboring farms affect the likelihood of any farm sustaining crop damage from baboons; and 3) in addition to the direct costs associated with crop losses attributed to baboon foraging activity, there are indirect costs of baboon crop raiding such as increased labor demands to protect crops from them and, occasionally, to replant crop stands badly damaged by baboons. These results have important implications for future primate conservation policy and practice.     

Status of arctic charr (Salvelinus alpinus) farming in Norway, Sweden and Iceland

This article describes the status of the Arctic charr (Salvelinus alpinus L.) aquaculture industry in Iceland, Norway and Sweden. The purpose of the work was to give an update on the status of Arctic charr farming in these countries based on information obtained from the industry itself. The data were collected using questionnaires designed for the purpose with key personnel in each country interviewing the farmers or farm managers. The questions were divided on topics focusing on different sides of the production, including farm characteristics, biological challenges and markets. The aim was to identify strengths and weaknesses in the production related to country and production technologies. The information may prove useful for decisions and prioritising future research and development work on removing bottlenecks and improving sustainable production of Arctic charr.     

How Ecosystem Services Knowledge and Values Influence Farmers' Decision-Making

The ecosystem services (ES) concept has emerged and spread widely recently, to enhance the importance of preserving ecosystems through global change in order to maintain their benefits for human well-being. Numerous studies consider various dimensions of the interactions between ecosystems and land use via ES, but integrated research addressing the complete feedback loop between biodiversity, ES and land use has remained mostly theoretical. Few studies consider feedbacks from ecosystems to land use systems through ES, exploring how ES are taken into account in land management decisions. To fill this gap, we carried out a role-playing game to explore how ES cognition mediates feedbacks from environmental change on farmers'' behaviors in a mountain grassland system. On a close to real landscape game board, farmers were faced with changes in ES under climatic and socio-economic scenarios and prompted to plan for the future and to take land management decisions as they deemed necessary. The outcomes of role-playing game were complemented with additional agronomic and ecological data from interviews and fieldwork. The effects of changes in ES on decision were mainly direct, i.e. not affecting knowledge and values, when they constituted situations with which farmers were accustomed. For example, a reduction of forage quantity following droughts led farmers to shift from mowing to grazing. Sometimes, ES cognitions were affected by ES changes or by external factors, leading to an indirect feedback. This happened when fertilization was stopped after farmers learned that it was inefficient in a drought context. Farmers'' behaviors did not always reflect their attitudes towards ES because other factors including topographic constraints, social value of farming or farmer individual and household characteristics also influenced land-management decisions. Those results demonstrated the interest to take into account the complete feedback loop between ES and land management decisions to favor more sustainable ES management.     

Coupled information diffusion--pest dynamics models predict delayed benefits of farmer cooperation in pest management programs

Worldwide, the theory and practice of agricultural extension system have been dominated for almost half a century by Rogers' "diffusion of innovation theory". In particular, the success of integrated pest management (IPM) extension programs depends on the effectiveness of IPM information diffusion from trained farmers to other farmers, an important assumption which underpins funding from development organizations. Here we developed an innovative approach through an agent-based model (ABM) combining social (diffusion theory) and biological (pest population dynamics) models to study the role of cooperation among small-scale farmers to share IPM information for controlling an invasive pest. The model was implemented with field data, including learning processes and control efficiency, from large scale surveys in the Ecuadorian Andes. Our results predict that although cooperation had short-term costs for individual farmers, it paid in the long run as it decreased pest infestation at the community scale. However, the slow learning process placed restrictions on the knowledge that could be generated within farmer communities over time, giving rise to natural lags in IPM diffusion and applications. We further showed that if individuals learn from others about the benefits of early prevention of new pests, then educational effort may have a sustainable long-run impact. Consistent with models of information diffusion theory, our results demonstrate how an integrated approach combining ecological and social systems would help better predict the success of IPM programs. This approach has potential beyond pest management as it could be applied to any resource management program seeking to spread innovations across populations.     

To treat or not to treat: diagnostic thresholds in subclinical helminth infections of cattle

Helminth infections of cattle place significant burdens on livestock production and farm economic efficiency. Heavy infections are relatively easy to detect and treat with anthelmintics. However, subclinical infections have major but often hidden impacts on animals, necessitating more refined diagnostics to detect them and ideally inform farmers about the likely impact of anthelmintic treatment on animal and herd performance. Here, we review recent advances in diagnosing three major cattle helminth infections – gastrointestinal nematodes (GINs), liver flukes, and lungworms – and the search for subclinical infection thresholds to guide treatment decisions. Combining refined diagnostic thresholds with farm-specific information on grazing systems and animal history enables farmers to tailor helminth treatments to specific epidemiological circumstances, thereby limiting anthelmintic resistance (AR) and boosting agricultural efficiency and food security.     

流域管理决策支持系统研究进展

流域管理决策支持系统是为帮助流域管理者实现水资源优化配置而研发的智能系统,其模拟结果直接影响流域管理的科学性和实用性.本文从水量模拟和调配系统、水质监测和评价系统、流域综合管理系统三方面总结了国内外的相关研究,并分析了现存系统的特点和存在的问题,同时简要介绍AQUA-Tool、Elbe-DSS、HD等代表性系统的模型结构和发展现状.模拟结果精确稳定、工作流程简洁、用户可视化程度高是流域管理决策支持系统的研发重点,优化方案选择模型和三维可视化工具、研发跨流域综合管理系统、提高利益相关者的参与度是未来该领域的发展方向.