Effects of increasing L-lysine HCl in corn- or sorghum-soybean meal-based diets on growth performance and carcass characteristics of growing-finishing pigs

• Published in: Journal of animal science Vol. 80; no. 9; pp. 2420 - 2432
• Main Authors: De la Llata, M, Dritz, S. S, Tokach, M. D, Goodband, R. D, Nelssen, J. L
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.09.2002; American Society of Animal Science
• Subjects: Amino Acids - deficiency; Animal Feed; Animal Nutritional Physiological Phenomena; Animal productions; Animals; Biological and medical sciences; Body Composition; Body Weight - drug effects; Digestion; Dose-Response Relationship, Drug; Eating; Female; Fundamental and applied biological sciences. Psychology; Glycine max; Hydrochloric Acid; Lysine - administration & dosage; Lysine - metabolism; Male; Meat - standards; Nutritional Requirements; Random Allocation; Swine - growth & development; Swine - metabolism; Terrestrial animal productions; Vertebrates; Zea mays; Performance evaluation; Monocotyledones; Animal feeding; Weight gain; Cereal crop; Carcass; Body composition; Fattening; Sorghum bicolor; Meat animals; Gramineae; Angiospermae; Ungulata; Farming animal; Zea mays; Experimental study; Pig; α-Aminoacid; Vertebrata; Mammalia; Treatment; Diet; Lysine; Spermatophyta; Artiodactyla
• ISSN: 0021-8812; 1525-3163

We conducted three experiments to determine the effects of increasing L-lysine HCl in growing-finishing pig diets. Experiments 1 and 2, conducted at the Kansas State University research center, each used 360 growing-finishing pigs with initial BW of 56 and 63 kg, respectively. Dietary treatments were sorghum- (Exp. 1) or corn- (Exp. 2) soybean meal-based and consisted of a control (no L-lysine HCl) or 0.15, 0.225, and 0.30% L-lysine HCl replacing lysine provided by soybean meal. Experiment 3 was conducted in a commercial research facility using a total of 1,200 gilts with an initial BW of 29 kg. Pigs were allotted to one of eight dietary treatments fed in four phases. These consisted of a positive control diet with no added L-lysine HCl and the control diet with 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30% L-lysine HCl replacing the lysine provided by soybean meal. The eighth dietary treatment was a negative control diet with no added L-lysine HCl and formulated to contain 0.10% less total lysine than the other treatments to ensure that dietary lysine was not above required levels. In Exp. 1, increasing L-lysine HCl decreased (linear, P < 0.01) ADG, feed efficiency (G:F), and percentage lean and increased (linear, P < 0.01) backfat depth. In Exp. 2, increasing L-lysine HCl decreased (quadratic, P < 0.03) ADG, G:F, and ADFI, but carcass characteristics were not affected. In Exp. 3, increasing L-lysine HCl decreased ADG (linear, P < 0.01) and G:F (quadratic P < 0.03). In all three experiments, the greatest negative responses were observed when more than 0.15% L-lysine HCl was added to the diet. Therefore, unless other synthetic amino acids are added to the diet, no more than 0.15% L-lysine HCl should replace lysine from soybean meal in a corn- or sorghum-soybean meal-based diet to avoid deficiencies of other amino acids. Based on the content of diets containing 0.15% Lysine-HCl, it appears the requirements for methionine plus cystine expressed as ratios relative to lysine are not greater than 50% during the early growing-finishing period (30 to 45 kg) and 62% during the late finishing period (90 to 120 kg) on a true digestible basis. For similar periods, the ratio requirements for threonine are not greater than 59% and 64% on a true digestible basis.