Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Carl P. Birkelo


Two trials were conducted, as randomized block designs, to assess the effects of com condensed distillers solubles (com CDS) on performance of steer calves fed 40% concentrate growing diets (Trial 1, n=200), and performance and carcass merit of yearling steers fed 90% concentrate finishing diets (Trial 2, n=216). Com CDS was included at 0 (MSBM), 5 (5CCDS), 10 (10CCDS) and 20% (20CCDS) of diet DM in both trials, replacing soybean meal molasses and com. A com silage/ supplement diet was also included in Trial 1 (SIL). In Trial 1, DMI at higher com CDS levels were lower than that of MSBM (P.20) and, as a result, gain efficiency (G/F) tended to improve (P=.14). Steers fed SIL consumed less DM (P.20). Steers in Trial 2 were harvested on d 117. Carcass weight (CW) and dressing percent (DP) for steers fed com CDS were greater than control steers (P>.20). Ruminal fluid was collected by stomach tube from steers in each trial (n=90 and n=72 at -0.5, +1, +4, and +7 h from feeding. Mean ruminal NH3N and mean molar proportions of acetate decreased (P3N and VFA concentrations in Trial 1. Ruminal pH decreased more rapidly and to a greater extent over time for SIL than other treatments. Acetate moral proportions were lower in corn CDS fed cattle at all samplings times while propionate molar proportions were higher than MSBM controls (P>.05). Ruminal NH3N concentrations from cattle on the 20CCDS 1 h after feeding were also much lower than other treatments and times (P3­N were not significant (P>.20). No time effects or time x treatment interactions were observed for ruminal NH3N or VFA concentrations. Corn CDS was an effective protein and energy source in both 40% concentrate growing diets and 90% concentrate corn-based finishing diets, although its means of impacting performance apparently differed between the diet types. Relative to animal performance, maximum inclusion rate is at least 20% of diet DM.

Library of Congress Subject Headings

Beef cattle -- Feeding and feeds
Distillers feeds




South Dakota State University



Rights Statement

In Copyright