Effect of Dietary Lysine on Plasma Amino Acid Profile and Selected Metabolites of Late-Stage Finishing Pigs

The objective of this study was to evaluate the effects of dietary lysine on plasma concentrations of amino acid (AAs) and other metabolites of finishing pigs. Eighteen crossbred late-stage finishing pigs (9 barrows and 9 gilts) were assigned to three dietary treatments, Diets I (lysine-deficient), II (lysineequate), and III (lysine-excess), according to a randomized complete block design with gender as block. After 4 weeks on trial, jugular vein blood were collected and centrifuged for plasma samples, which were analyzed for concentrations of 24 AAs using HPLC method and 6 selected metabolites related to major nutrient metabolism using ACE Alera Clinical Chemistry System. Dietary lysine had a significant effect on plasma concentrations of 13 AAs and 3 metabolites (albumin, cholesterol, and urea nitrogen). The patterns of AA and metabolite concentrations alteration indicated complex metabolic interactions between lysine and other AAs, which subsequently had effects on other metabolites and animal growth performance