COW CULLING DECISIONS ADAPTED FOR MANAGEMENT WITH CART

A stochastic dynamic programming (DP) model of range cow culling decis ions incorporating market price uncertainties and dynamics of biologic al productivity was solved for biannual and annual calving systems. De cision trees were generated from the DP solutions using the Classifica tion and Regression Trees (CART) methodology. The decision trees captu red over 99% of the optimal DP returns from both biannual and spring-o nly calving. CART culling criteria in conjunction with dual-season cal ving increased wealth by 7% compared to optimal DP culling decisions w ith spring-only calving, and by 10% compared to a more traditional str ategy of culling all open cows.