Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science

First Advisor

Richard C. Wahlstrom


Lysine is the first limiting amino acid in most cereal-based diets for swine. Thus, in cereal-based diets the lysine- requirement must be met first if the pig's protein anabolism is to be efficient and maximal. The most widely used diet in the swine industry today is the corn-soybean meal diet. Corn is deficient in lysine, but soybean meal is a relatively good source of lysine, so soybean. meal is added to the corn base to increase the diet's lysine content. Synthetic lysine also can be added to corn-soybean meal diets to increase lysine content or added as a replacement for part of the soybean meal. However, the dietary protein level should be reduced a maximum of only 2% or other amino acids may become limiting. Recent research has indicated that the lysine level recommended by the National Research Council (NRC) may be inadequate for maximum growth and feed efficiency for 10- to 20-kg pigs. This is in agreement with European estimates of the lysine requirement for starter pigs. In fact, many commercial starter diets contain lysine levels closer to European recommendations than that level recommended by the NRC. However, little research has been conducted to determine if the higher lysine levels responsible for improved performance in the starter period are beneficial to performance for the entire growth period (8 to 100 kg). or if higher levels of lysine in starter diets affect carcass characteristics of finished pigs. Therefore, it is important to determine if increasing the lysine content of starter diets is economically beneficial when raising pigs from approximately 8 to 100 kg. The ultimate objective of this study was to determine the optimum lysine level in swine starter diets (8 to 20 kg) which would result in maximum performance from 8 to 100 kg without adversely affecting carcass characteristics. The parameters used were as follows: (1) Pig performance as measured by average daily gain, average daily feed intake and feed efficiency during the starter (8 to 20 kg) , grower (20 to 35 kg and 20 to 55 kg), finishing (35 to 100 and 55 to 93 kg) and overall (8 to approximately 100 kg) periods. (2) Quantitative carcass characteristics at 100 kg including carcass length, average backfat, longissimus muscle area and percent muscle.

Library of Congress Subject Headings

Swine -- Feeding and feeds
Swine -- Growth
Swine -- Carcasses
Lysine in animal nutrition



Number of Pages



South Dakota State University


No Copyright - United State