Life Sciences Commons^™

The Energy Expenditure Of Heifers Grazing Crested Wheatgrass Rangeland In West-Central Utah, Kris M. Havstad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The free-roaming ruminant requires energy for the demands of vii grazing, traveling and thermoregulation that are not required by its confined counterpart. Literature estimates of these additional costs range from 10 to 170 percent above maintenance. The uncertain magnitude of this increased demand and the factors that contribute to it impede the ability of the rangeland ruminant nutritionist to establish guidelines for the energy requirements of the free-roaming herbivore. This study was designed to estimate the energy expenditure of yearling Angus heifers while grazing a declining supply of available crested wheatgrass forage (Agropyron cristatum) on rangeland in west-central …

Diversity And Production Of Herbaceous Vegetation In A Northern Utah Subalpine Chronosequence, Gary A. Reese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Successional trends in herbaceous plant production and diversity were studied in an age sequence of sites, i.e. chronosequence, inferred to represent a meadow to aspen to fir to spruce-fir sere. Primary production was observed to decrease in a linear fashion with successional development. Three components of diversity; richness, heterogeneity, and equitability or evenness, each had low early successional values, reaching maximum diversity in mid-succession, and declining to intermediate levels with maturity. The magnitude of these trends varied greatly, depending on the methods used to determine plant dominance. Characteristics of various dominance indices and their applicability to this study were examined. …

Economic Analysis Of Long-Term Management Strategies For Two Sizes Of Utah Cattle Ranches, Roger E. Banner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah cattle ranchers realize relatively little profit from ranch ownership and management. This study represents an attempt to identify ranch management strategies that produce more profit over time than do conventional strategies.

To identify optimum management strategies for the long term, analyses of ranches under both normal and adverse ranch operation conditions using the COPLAN linear programming model were made for strategy comparison. To depict these ranch business environmental conditions, production levels were estimated from available biological data and price levels were estimated by indexing 1977 ranch product prices (the most current budget data available for Utah). The variability of …