Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Dairy Science

First Advisor

David J. Schingoethe


In vitro dry matter digestibility (IVDMD) of sunflower hulls (SFH) treated with sodium hydroxide (NaOH), ammonium hydroxide (NH4OH), and potassium hydroxide (KOH) at increasing levels were studied. Tested concentrations of each alkali as percent dry matter (DM) on SFH were 1.63, 2.45, 3.26, and 4. 08. In vitro dry matter digestibility of sunflower hulls increased with higher concentrations of NaOH and KOH. Percent IVDMD for control (un-treated SFH) was 18.0. Percent IVDMD for SFH treated at 1.63, 2.45, 3.26, and 4.08% of DM were: 18.9, 21.4, 22.2, and 22.9 for NaOH; 18.3, 18.0, 18.3, and 18.5 for NH4OH; and 18.9, 20.2, 21.0, and 22.5 for KOH. Twenty wethers averaging 41 kg were utilized in a switch-back design experiment to evaluate the in vivo digestibility of alkali treated SFH. Diets contained 0% SFH (positive control), 25% of DM as untreated SFH (negative control), or 25% of DM as SFH treated with 2.45% NaOH, 2.45% KOH, or 3.42% NH4OH. Other ration components were alfalfa meal, corn, soybean meal, dicalcium phosphate, trace mineralized salt, and vitamins. All rations were made isonitrogenous at 14.6% crude protein and pelleted. Feed and water consumptions were highest with diets containing alkali treated SFH, especially NaOH and KOH treated SFH. Digestibilities of acid detergent fiber and neutral detergent fiber (%) for the respective diets were: positive control, 42.6 and 58.2; untreated SFH, 30.2 and 42.9; NaOH treated SFH, 34.3 and 44.0; NH4OH treated SFH, 26.2 and 35.3; and KOH treated SFH, 37.4 and 42.0.

Library of Congress Subject Headings

Ruminants -- Feeding and feeds
Sunflowers -- Seeds


Includes bibliographical references (pages 48-56)



Number of Pages



South Dakota State University

Included in

Dairy Science Commons