Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Richard C. Wahlstrom


Supplementation of individual amino acids to low protein swine diets is of current interest in the swine industry due to attempts to reduce feed costs. Although cereal grains provide the majority of the total protein requirements for swine, the remainder must be supplied either from natural protein supplements or synthetic amino acids. Research has shown amino acid content and balance are of greater importance than total protein alone in meeting nutrient needs. Because of this, a great deal of effort has been directed toward determining single amino acid requirements of swine. Research of this nature is complicated by the varying levels and availabilities of amino acids found both within and among feedstuffs and the numerous interrelationships concerning utilization of amino acids in the animal body. Recently, additions of amino acids to low protein diets resulting in improved performance has stimulated research attempting to identify limiting amino acids in swine diets and the level of supplementation needed to achieve performance equal to that obtained by feeding diets containing protein levels currently recommended for swine. Amino acid requirements for young pigs differ when expressed as a pe1"cent of the diet. Some of this variation can be attributed to differences in the level of dietary protein fed. A factor often prohibiting additions of amino acids to swine diets is cost. Presently, only a few synthetic amino acids can be supplemented economically. The cost of natural protein supplements can be expected to increase, consistently, studies on supplementation of cereal proteins with synthetic amino acids are needed. Amino acid use will increase if they can be made available at a price which provides a feasible alternative to natural protein. The trials reported herein were ·designed to (1) determine the efficacy of replacing DL-tryptophan with N-acetyl-DL-tryptophan and (2) to determine the level of tryptophan supplementation to a low protein corn-soybean meal starter diet for optimum performance.

Library of Congress Subject Headings

Swine -- Feeding and feeds.
Feed additives.
Amino acids in animal nutrition.



Number of Pages



South Dakota State University