Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Zachary Smith


Two randomized complete block design feedlot experiments were conducted over the course of two years. These experiments were conducted to investigate the effects of 1) evaluate the observed-to-expected ratio for ingredient inclusion using no commodity inclusion assistance technology or using commodity inclusion assistance technology; and 2) evaluate the influence that varying degrees (highly variable at random or 0.454 kg asfed tolerance for each ingredient) of accuracy on ingredient inclusion have on growth performance, carcass traits, efficiency of dietary NE utilization, and ingredient inventory management in finishing beef cattle. Experiment 1 used single source Black Angus heifers (n = 60; initial shrunk BW = 460 ± 26.2 kg). Experiment 2 used single source Charolais-Angus cross steers (n = 128; initial shrunk BW = 505 ± 32.1 kg). Heifers and steers were allotted to 1 of 2 dietary treatments: 1) 0.454 kg as-fed tolerance for each ingredient (CON), or 2) highly variable at random (VAR). In Exp. 1, applying a highly variable at random dietary inclusion did not affect ADG, dry matter intake (DMI), or feed conversion efficiency (P ≥ 0.15). There were no differences (P ³ 0.35) detected between treatments for HCW, dressing percentage, rib eye area, rib fat, USDA marbling score, KPH, yield grade, retail yield, empty body fat, or body weight at 28% estimated EBF. In Exp. 2, highly variable at random dietary inclusion showed an increase in (P £ 0.01) DMI and reduced (P £ 0.02) kg of gain to kg of feed (G:F) for VAR. However, no differences (P = 0.75) were detected between treatments for ADG. In addition, Net Energy for maintenance and gain was decreased (P £ 0.01) in VAR. Carcass characteristics for both treatments showed no treatment effect (P ³ 0.38) on HCW, dressing percentage, rib eye area, rib fat, KPH, Yield Grade, retail yield, empty body fat, or body weight at 28% estimated EBF. A tendency for increased USDA marbling score (P > 0.08) was noted in VAR. Under the conditions of this experiment, randomly altering ingredient proportions negatively affected feed efficiency with no change in carcass characteristics.

Library of Congress Subject Headings

Beef cattle -- Feed utilization efficiency.
Beef cattle -- Feeding and feeds.


South Dakota State University

Included in

Beef Science Commons



Rights Statement

In Copyright