COW CULLING DECISIONS ADAPTED FOR MANAGEMENT WITH CART

A stochastic dynamic programming (DP) model of range cow culling decisions incorporating market price uncertainties and dynamics of biological productivity was solved for biannual and annual calving systems. Decision trees were generated from the DP solutions using the Classification and Regression Trees (CART) methodology. The decision trees captured over 99% of the optimal DP returns from both biannual and spring-only calving. CART culling criteria in conjunction with dual-season calving increased wealth by 7% compared to optimal DP culling decisions with spring-only calving, and by 10% compared to a more traditional strategy of culling all open cows.