This paper presents a multiperiod planning tool for multisite pig production systems based on Linear Programming (LP). The aim of the model is to help pig managers of multisite systems in making short-term decisions (mainly related to pig transfers between farms and batch management in fattening units) and mid-term or long-term decisions (according to company targets and expansion strategy). The model skeleton follows the structure of a three-site system that can be adapted to any multisite system present in the modern pig industry. There are three basic phases, namely, piglet production, rearing pigs, and fattening. Each phase involves a different set of farms; therefore, transportation between farms and delivering of pigs to the abattoir are under consideration. The model maximizes the total gross margin calculated from the income of sales to the abattoir and the production costs over the time horizon considered. Production cost depends on each type of farm involved in the process. Parameters like number of farms per phase and distance, farm capacity, reproduction management policies, feeding and veterinary expenses, and transportation costs are taken into account. The model also provides a schedule of transfers between farms in terms of animals to be transported and number of trucks involved. The use of the model is illustrated with a case study based on a real instance of a company located in Catalonia (Spain). Copyright © 2014. American Society of Animal Science .

This paper presents a bi-objective model for optimizing pig deliveries to the abattoir accounting for total revenue and CO ${}_2$ emissions. Fattening farms house the most important stage in pig production, and operations on farms must be coordinated with the rest of the pig supply chain when batch management is generally applied. The novelty of the model lies in the change of attitude in producers towards a greener production, which is becoming one of the major concerns in our society. In this context, we enrich the classical approach focused on revenues with the addition of the CO ${}_2$ emissions from the pigs on the fattening farms. Emissions derived from feeding and transportation are considered since they are the most important sources of CO ${}_2$ . The model is tested using parameters representing a typical integrated Spanish fattening farm. Our findings reveal the impact and the relationship between revenues and emissions, highlight that the break-even is reached achieving 459 kg of CO ${}_2$ per pig, which corresponds to a reduction of 6.05%. On the other hand, the profit is slightly reduced by 4.48% in favor of the environment.