Diversity and sustainability of pig farm types in the northern mountains of Vietnam.

Pig farming systems in Vietnam are very diverse but little is known about this diversity. In particular, the different livestock farming systems currently in operation do not have the same capacity to be sustainable. The study aims to categorize farming systems involving pig production and investigate their sustainability. Data were collected from 160 family pig farms and 2 large-scale farms in Mai Son district of Son La province (northwest of Vietnam) using stratified random sampling. The multiple factor analysis method was used to identify different farms and to characterize each type with economic, social, and environmental indicators. The results highlighted four different farm types. Type 1 contained smallholder farms with diversified farm activities. They were mainly farmed by ethnic minorities located in the intermediate highland. They had low labor productivity and relied mainly on crop farming. Pig production was characterized by a low level of economic and social sustainability. Type 2 farms had comparatively less land and crops than other types. They were more specialized in livestock production, had medium-size pig herds, and were engaged in off-farm jobs. They were less dependent on credit or location and performed better with regard to environmental issues than larger farm types. Type 3 was specialized farms with large pig herds. They seemed more sustainable in economic and social components than the other types, but their environmental sustainability was questionable. Type 4 contained large mixed crop-livestock farms. They obtained high income but were more dependent on credit than the other types. In the future, in addition to focusing on large-scale specialized farms, policies should also consider small-scale and diversified farms because of their role in the sustainable development of national pig production.

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.

Understanding the reproductive performance of a dairy cattle herd by using both analytical and systemic approaches: a case study based on a system experiment.

Reproductive performance has recently been a growing concern in cattle dairy systems, but few research methodologies are available to address it as a complex problem in a livestock farming system. The aim of this paper is to propose a methodology that combines both systemic and analytical approaches in order to better understand and improve reproductive performance in a cattle dairy system. The first phase of our methodology consists in a systemic approach to build the terms of the problem. It results in formalising a set of potential risk factors relevant for the particular system under consideration. The second phase is based on an analytical approach that involves both analysing the shapes of the individual lactation curves and carrying out logistic regression procedures to study the links between reproductive performance and the previously identified potential risk factors. It makes it possible to formulate hypotheses about the biotechnical phenomena underpinning reproductive performance. The last phase is another systemic approach that aims at suggesting new practices to improve the situation. It pays particular attention to the consistency of those suggestions with the farmer's general objectives. This methodology was applied to a French system experiment based on an organic low-input grazing system. It finally suggested to slightly modify the dates of the breeding period so as to improve reproductive performance. The formulated hypotheses leading to this suggestion involved both the breed (Holstein or Montbéliarde cows), the parity, the year and the calving date with regard to the turnout date as the identified risk factors of impaired performance. Possible use of such a methodology in any commercial farm encountering a biotechnical problem is discussed.