title: Effect of L-lysine on expression of selected genes, serum concentration of amino acids, muscle growth and performance of growing pigs.
abstract: Lysine (Lys) is the first limiting amino acid (AA) in most feed formulations for pigs and most abundant, along with leucine, in muscle proteins. An experiment was conducted with 17 pigs (17.7 ± 0.05 kg initial BW) to identify a role of dietary Lys in the control of protein synthesis in pigs. Fourteen pigs were randomly assigned to one of the two wheat-based dietary treatments: Lys-deficient, 3.0 g/kg (DEF) and Lys-adequate, 10.8 g/kg (ADE). Samples from jejunum mucosa, liver, Longissumus and Semitendinosus muscles, and blood were collected. The other three pigs were sacrificed at the beginning of the trial to measure basal carcass composition. Weight gain, gain:feed ratio, Lys intake and loin eye area were greater in ADE than in DEF pigs (p < 0.01). Muscle-related carcass characteristics were better, and myosin heavy chain IIb expression (MyHC IIb) in Semitendinosus was higher in ADE than in DEF pigs. Expression of AA transporters CAT-1 was lower (p < 0.05), serum Lys was higher and serum Val was lower in pigs fed the ADE diet. The higher muscularity, MyHC IIb expression in Semitendinosus muscle and Lys serum of pigs fed the ADE diet suggest that Lys increases growth rate not only by functioning as protein construction unit but also as potential control of the protein synthesis process.
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: A
authors.initials: A
authors.lastname: Morales
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: H
authors.initials: H
authors.lastname: García
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: N
authors.initials: N
authors.lastname: Arce
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: M
authors.initials: M
authors.lastname: Cota
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
authors.forename: R T
authors.initials: RT
authors.lastname: Zijlstra
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: B A
authors.initials: BA
authors.lastname: Araiza
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Mexicali, BC, México.
authors.forename: M
authors.initials: M
authors.lastname: Cervantes
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism; D000596:Amino Acids / Q000097:blood*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005786:Gene Expression Regulation / Q000187:drug effects*; D008239:Lysine / Q000008:administration & dosage / Q000494:pharmacology*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000254:growth & development*; D013552:Swine / Q000254:growth & development*; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D008239:Lysine
keywords: gene expression; lysine; myosin; pig performance; serum amino acid