Simulation of cow-calf production systems in a range environment: II. Model evaluation

Development of a general beef cattle simulation model was described in a co mpanion paper. The objectives of this research were to demonstrate and eval uate the model's performance. Four experiments were conducted to demonstrat e 1) life-cycle weight and body condition changes for different genotypes r aised in a northern range environment; 2) responses in forage intake and we ight to changes in forage quality, protein supplementation, and cow physiol ogical state; 3) responses in reproduction, weight, body condition, and cal f growth to differences in pre- and postpartum nutrition; and 4) difference s in enterprise efficiency and profit for different genotypes and mating sy stems. Results indicated that the model performs acceptably for the types o f situations for which it was designed and highlighted areas of animal scie nce where more information is needed in order to better understand and mani pulate beef cattle systems. Computer simulation models are useful tools to facilitate the integration of scientific concepts and to help scientists, t eachers, and producers better understand the complex production systems tha t they study and manage. In addition to addressing enterprise-level problem s that are beyond the scope of traditional experimentation, modeling and si mulation help identify research needs and foster exchange among disciplines .