Herd dynamics age and sex structured model considering management practices and animal movements among districts

Abstract

Mathematical models applied to livestock systems are an important tool for their analysis and planning, which can be used to improve their profitability, as well as for sanitary purposes. An age and sex structured model formulated in differential equations was developed for simulating the dynamics of a cattle herd population in a district. Since management practices determine the herd’s structure, this model considers explicitly common practices, such as seasonal service, calving, weaning and the replacement of animals for reproduction, usually implemented in Argentina’s livestock system. Movements between districts are also incorporated into the model, following the national livestock movements database. This model can be used to analyze the effect of different management practices. The herd population dynamics was simulated with and without movements between districts, showing how movements influence the local dynamics and in the herd structure. Population dynamics in two districts with different main productive activity (breeding and fattening) are compared and discussed.