Effects of Increasing L-Lysine HCl on Finishing Pig-Growth Performance and Carcass Characteristics

Kansas State University Swine Research. We conducted two studies to determine the effects of increasing L-lysine HCl in finishing pig diets. Experiment 1 used sorghum-soybean meal-based diets, and Exp. 2 used corn-soybean meal-based diets. Treatments included a control diet (no L-lysine HCl) or .15, .225, and .30% L-lysine HCl replacing the lysine provided by soybean meal. In Exp. 1, increasing L-lysine HCl from 0 to .15% had no effect on ADG, F/G, and percentage lean; however, pigs fed .225 and .30% L-lysine HCl had poorer ADG, F/G, and percentage lean. In Exp. 2, ADG and F/G were poorer for pigs fed .225 or .30% Llysine HCl compared with those fed the control diet or .15% L-lysine. Carcass charactistics were not affected by dietary treatment but tended to become poorer in pigs fed .225 or .30% L-lysine HCl. Unless diets are fortified with other amino acids, no more than .15% (3 lb/ton) L-lysine HCl should be added to sorghum- and corn-soybean meal finishing diets.