Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Richard C. Wahlstrom


The ultimate goal of the pork industry is efficient production of quality pork for the least monetary investment. Most swine diets are formulated using feedstuffs which supply 100% natural protein. Different protein sources differ in their amino acid content and availability. For example, soybean meal has been shown to contain more lysine than sunflower meal and the lysine in soybean meal is more available to the pig than that of sunflower meal. Protein sources which supply the correct balance of available amino acids relative to the needs of the animal are considered as being protein sources of the highest monetary as well as biological value. Within the last decade the amino acid lysine, which is normally first limiting in swine diets, has become available in synthetic form in quantity and price that make it economically feasible for use in swine diets. It was also discovered that the protein content of diets containing excesses of other essential amino acids could be lowered, without affecting pig performance, when diets were supplemented with lysine. These discoveries, in which it was shown that a synthetic amino acid could replace its natural counterpart have made it possible to correct previously imbalanced diets and/or lower the amount of natural protein required when supplementing with synthetic amino acids. Wahlstrom et al. fed a lysine supplemented, low protein, corn-sunflower meal diet to young pigs and reported that pigs responded to additions of tryptophan and threonine. Thus, the basis for the research reported therein was established. The objectives were to identify the optimum levels of the limiting amino acids tryptophan and threonine in a lysine supplemented, low protein sunflower meal diet.

Library of Congress Subject Headings

Swine -- Feeding and feeds
Amino acids in animal nutrition
Lysine in animal nutrition



Number of Pages



South Dakota State University


No Copyright - United State