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.

应用于牲畜系统的数学模型是对其进行分析和计划的重要工具，可用于提高其盈利能力以及用于卫生目的。建立了以微分方程式表示的年龄和性别结构模型，用于模拟一个地区的牛群种群动态。由于管理实践决定了畜群的结构，因此该模型明确考虑了常见的实践，例如季节性服务，产犊，断奶和替换动物以繁殖，通常在阿根廷的牲畜系统中实施。遵循国家牲畜移动数据库，地区之间的移动也被纳入模型。该模型可用于分析不同管理实践的效果。

在区域之间有无运动的情况下，模拟了种群动态，显示了运动如何影响局部动力学和种群结构。比较和讨论了两个主要生产活动（育种和育肥）不同的地区的人口动态。