A decision-making steer feedlot using static and dynamic planning

Meat in terms of providing needed proteins، food security in the country and its share of value added agriculture in agricultural sector has a special place. In this study، first steer feedlot was modeling (Holstein and racial composition) in order to estimate the optimal age for the sale of animals using a simple linear mathematical programming (static) and then decision making for livestock feeding or replacement of new one was discussed by dynamic planning. Required data was prepared by questionnaire from 5 industrial livestock in Qazvin (Holstein and racial composition) and the Statistical Center of Iran. Results showed that if an animal life considered cyclical، sixteen months is optimal; and if it is several cycles، nine months will be optimum production. For sensitivity analysis of parameters in the model، different scenarios were considered in terms of growth performance parameters، weight was more effective than other livestock parameters. Ultimately the decision making of animal feed and replacing it with a new one was evaluated using stochastic dynamic programming. Results showed that in weights 300-398، livestock nutrition should continue and therefore in average 0. 5 kg weight per day increase and in weights 405-440، new livestock must be replaced.