Multi-goal pig ration formulation; mathematical optimization approach
¹University of Ljubljana, Biotechnical Faculty, Deptartment of Animal Science, Groblje 3,SI-1230 Domžale, Slovenia; e-mail: jaka.zgajnar@bfro.uni-lj.si
²The same address as 1
Abstract:
Organically produced pork is characterized by high production costs, within the main part goes to ration cost. Forage must be produced under strict conditions, reflecting in high prime costs. The main challenge for farmers is how to formulate economically efficient, nutrition balanced and politically acceptable rations at the least-cost to be competitive. This challenging task demands handy tool that merges all three viewpoints. In this paper an example of such a tool, based on three step approach, is presented. In the first step, a common linear program is utilized to formulate least-cost ration. In the second step, a sub-model, based on weighted goal programming and supported by a system of penalty functions, is used to formulate a nutritionally balanced and economically acceptable ration that also fulfils conditions demanded by organic farming. The most ‘efficient’ energy content of the ration is searched in the last step. The obtained results confirm the benefits of the applied approach.
Key words:
mathematical programming, organic farming, pork, ration costs