Amino Acid Supplementation of a Corn-Cottonseed Meal Diet for Growing-Fattening Swine1

A significant growth response was obtained by supplementing a corncottonseed meal type diet for swine with dl lysine. There was a highly significant difference in the response resulting from feeding different levels of dl lysine. The optimum level of supplementary dl lysine fed in the presence of fish solubles was 0.1 percent. Levels of supplementary dl lysine greater than 0.1 percent appeared to depress growth, whereas, levels lower than 0.1 percent failed to support maximum growth. The addition of dl tryptophan at levels used in these experiments promoted growth significantly when added in the presence of fish solubles. The addition of 0.05 percent dl methionine did not result in a statistically significant growth response. Significant increases in growth rate were paralleled by increases in efficiency of feed utilization.