Limited land, labour, feed, and financial resources determine the production structure of farms, while increasingly stringent sustainability requirements require economic efficiency to be balanced with the rational use of natural resources. The study aimed to substantiate an optimal production programme for a mixed farm using economic and mathematical modelling that accounts for economic, resource, technological, and environmental constraints. The information base was developed using official statistical data for 2024-2025. A mixed-integer linear programming (MILP) model implemented in R was used to optimise the production structure. The model incorporated constraints on land, labour, feed, and financial resources, as well as greenhouse gas emissions, livestock density, soil organic matter balance, and water use. Scenario analysis was applied to assess the effects of additional requirements. Under the baseline scenario, the optimal plan included 32 head of cattle, 1.18 t of poultry, 9.84 ha of berries for wholesale sales, and 10.00 ha for retail sales, generating a contribution margin of UAH 3,001.94 thousand. Environmental constraints reduced the number of cattle to 28 head and increased poultry production to 5.63 t, while berry production areas changed only slightly. The water constraint resulted in a reduction in the area allocated to berry production and a change in the livestock structure. The combined application of environmental and water constraints produced the most substantial structural adaptation and reduced the contribution margin by 16.60% compared with the baseline scenario. The practical significance of the study lies in the possibility of using the model to substantiate farm production programmes and assess their adaptation to changes in resource and environmental conditions