Life cycle evaluation of five biological types of beef cattle in a cow-calf range production system. I. Model development

• Published in: Journal of animal science Vol. 72; no. 10; p. 2585
• Main Authors: Davis, K.C. (Montana State University, Bozeman), Tess, M.W, Kress, D.D, Doornbos, D.E, Anderson, D.C
• Format: Journal Article
• Language: English
• Published: United States 01.10.1994
• Subjects: Animal Feed - economics; Animal Husbandry - economics; Animals; APLICACIONES DEL ORDENADOR; APPLICATION DES ORDINATEURS; Body Weight; BOVIN DE BOUCHERIE; Breeding; Cattle - genetics; Cattle - physiology; Cattle Diseases - epidemiology; Computer Simulation; COSTOS DE PRODUCCION; Costs and Cost Analysis; COUT DE PRODUCTION; DIFERENCIAS BIOLOGICAS; DIFFERENCE BIOLOGIQUE; Dystocia - epidemiology; Dystocia - veterinary; Eating; Energy Intake; Energy Metabolism; Female; GANADO DE CARNE; Income; LACTACION; LACTATION; Lactation - physiology; Least-Squares Analysis; Male; MODELE DE SIMULATION; MODELOS DE SIMULACION; Models, Biological; MONTANA; POSSIBILITE DE PRODUCTION; Pregnancy; PRODUCCION POTENCIAL; RACE; RAZAS; RENTA DE LA EXPLOTACION; Reproduction; REVENU DE L'EXPLOITATION; SIMULACION; SIMULATION; Stochastic Processes; Survival Rate; VIGOR HIBRIDO; VIGUEUR HYBRIDE
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1994.72102585x

Data collected during a 10-yr study at the Northern Agricultural Research Center (NARC), Havre, MT were used in construction of a simulation model to evaluate production systems using different breed groups. Five dam breed groups, straightbred Hereford (HH), 50% Angus-50% Hereford (AH), 25% Simmental-75% Hereford (lS3H), 50% Simmental-50% Hereford (lSlH), and 75% Simmental-25% Hereford (3S1H), were studied. The simulated system was a northern range cow-calf production system with spring calving and fall weaning. Replacement heifers were purchased and all calves were marketed at weaning. All nonpregnant females were sold in the fall. Statistical analyses of the data yielded input values (least squares means for breed group X age X sex subclasses) for cow and calf weights, pregnancy rate, dystocia, and calf survival. Pregnancy, dystocia, calf survival, calf weights, and cow weights were simulated stochastically. Energy requirements for maintenance, growth, gestation, and lactation were predicted from equations adapted from the literature based on body weight, frame size, sex, and breed group. Economic inputs and outputs were computed by accounting for variable input expenses and output revenues associated with animal performance and fixed costs associated with range management. Simulated measures of system performance included measures of energy conversion, break-even prices, and profit