• Yaroslav M. Ivanyo, Irkutsk State Agricultural University named after A.A. Ezhevsky (Molodezhny, Irkutsk municipal district, Russia)
• Enkhbat Ariunjargal, Irkutsk State Agricultural University named after A.A. Ezhevsky (Molodezhny, Irkutsk municipal district, Russia)

The aim of this study is to develop an optimization model for determining the rational livestock structure and population size for various livestock species in a given area, taking into account farm specialization and the environmental load on land resources. This is the first model developed that allows for determining the livestock structure and population size under conditions of pasture livestock farming, both with and without pasture land degradation, which is relevant for Mongolian agriculture. The model's objective function is profit-oriented. Constraints include production volumes, provision of animals with feed and nutrients, labor costs for animal maintenance, water supply, environmental requirements for pasture use by animals, and the population size of different groups. Since the supply of feed for livestock is determined by the yield of forage crops on pastures, the dynamics of forage crop yields on pastures in different regions of Mongolia are analyzed based on data from 1960 to 2024. It is shown that harvest volumes from 1992 to the present can be described using an exponential function for the Western, Khangai, Central, and Eastern regions of Mongolia. The model was implemented using households with different industry specializations. The following livestock species were analyzed: sheep, goats, horses, cattle, and camels. A certain average farm size was identified based on pasture area and labor costs for production. The production, economic, and environmental characteristics of the model were determined. Optimal solutions were calculated for households with different specializations, with and without pasture degradation. A comparative analysis of the results was conducted, and the best options for maximum profit were obtained. The LP Solve application was used to implement the developed model. The developed model is useful for production planning with different livestock specializations and varying levels of pasture degradation.

linear programming, optimization, pasture livestock farming, pasture degradation, Mongolia

2026-09-03