determine the removal rate under the optimal alternative milking strategy for different production and health conditions in dairy cattle of Ardabil province.

The purpose of this study was to determine the removal rate under the optimal alternative milking strategy for different production and health conditions in dairy cattle of Ardabil province. One of the most important management decisions that affect livestock production is the timely replacement of dairy cattle with young heifers. Using the system analysis method, the economic system of the dairy cattle was split into income and cost components and each of these components was subdivided into other parts. Then, using the existing models and using the Compecon Combinator tool kit, Matlab programming language was used to simulate a bioeconomic model. The objective function was to maximize the net present value of the livestock in a planning horizon with 10 lactation periods. Dairy cattle were defined by state variables including lactation period, milk production capacity, and different mastopathic outbreaks..In each stage, dairy cattle were classified by state variables including production capacity in 3 levels (low production, moderate and high production), and health status in 3 levels (non-disease, treatable disease, and disease that eliminated livestock). he results of the model analysis showed that the maintenance of dairy cows up to the sixth stomach and the average cows production until the fourth stomach is economically justified and the maintenance of low production cows is not recommended.