Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Wildland Resources

Department name when degree awarded

Range Science

Committee Chair(s)

John P. Workman


John P. Workman


Roger Banner


Chris Call


Rob Lilieholm


Fred Provenza


Allen Rasmussen


The purpose of this study was to determine the optimum combination of various cattle production, range forage, and crop harvesting alternatives available to ranch owners and managers in Utah. While many promising alternatives are available, determining which alternatives to implement is difficult because the total ranch operation must be considered.

Linear programming (LP) is a tool available to ranch managers which allows the profit maximizing combination of improvements to be easily determined. LP allows ranchers to examine the entire ranch operation and to reduce the amount of risk and uncertainty involved in the decision making process.

The typical Utah ranch operation was described from a sample of 96 Utah ranches. Sixteen potential cattle options, 11 range forage options, and 3 crop options were developed to improve net variable cash ranch income of the typical Utah ranch. An LP model was developed to determine the optimum combination and level of options, the most efficient options, and the limiting constraints. Four scenarios based on range site and bush infestation type were compared to add flexibility to the model.

The optimal solution ran 266 brood cows under the O'Connor Management System (cows in moderate body condition at calving, 60-day calving season, 48-hour calf removal, cows gaining weight for 5 weeks starting 2 weeks before breeding season, and cows bred to fertile bulls) compared to 196 brood cows under the typical situation. In all optimization runs, burning big sage brush (artemesia tridentata) or pinyon-juniper (Pinus - Juniperus) infestations on crested wheatgrass (Agropyron desertorum) foothill ranges was the most economically efficient range forage option. The most economically efficient crop option was the combination of grazing the grass hayfields and custom harvesting the alfalfa hayfields. It was necessary to construct stock water ponds and properly distribute salt to increase summer forage availability. The optimum combination of improvements required 808 hours of hired labor. The net variable cash ranch income after burning sagebrush or pinyon-juniper types was $56,145 and $55,861, respectively compared to $31,278 for the typical Utah cow-calf operation. The optimal solution will change as input and product prices change. The model was not designed to make general recommendations but to be applied to specific ranching operations.