title: The effect of the protein level in a pre-starter diet on the post-hatch performance and activation of ribosomal protein S6 kinase in muscle of neonatal broilers.
abstract: The cytoplasmic serine/threonine ribosomal protein S6 kinase (S6K1) plays a critical role in controlling protein translation. There is evidence that amino acids regulate S6K1 and protein synthesis in avian species, but the effect of dietary protein level on the activation of S6K1 in neonatal chicks is unknown. Therefore, the aim of the present experiment was to investigate the effect of different protein levels, supplied during the first 5 d post-hatch, on body growth, breast muscle development and on the activation of S6K1 and its downstream target, the S6, in neonatal chicks. Chicks were fed a pre-starter diet during the first 5 d post-hatch containing low (19.6 % crude protein (CP); LP), medium (23.1 % CP; MP) or high (26.7 % CP) levels (HP) of protein. Weight gain of chicks fed the HP diet was higher (P < 0.05) compared with those fed the LP diet during day (d)3-d5 and the numerical advantage of this group was maintained from d2 to d7. On d2 and d3, greater levels of S6K1 and S6 phosphorylation and/or activity were observed in chicks receiving the HP diet compared with LP and MP diets, without differences between results of the latter two dietary treatments. In conclusion, the present results suggest that early protein nutrition impacts the development of broiler chicks.
authors.affiliation: Laboratory for Physiology and Immunology of Domestic Animals, Department of Biosystems, K.U. Leuven, Kasteelpark Arenberg, 30, 3001 Leuven, Belgium. nadia.everaert@biw.kuleuven.be
authors.forename: Nadia
authors.initials: N
authors.lastname: Everaert
authors.forename: Quirine
authors.initials: Q
authors.lastname: Swennen
authors.forename: Sonia Métayer
authors.initials: SM
authors.lastname: Coustard
authors.forename: Hilke
authors.initials: H
authors.lastname: Willemsen
authors.forename: Christine
authors.initials: C
authors.lastname: Careghi
authors.forename: Johan
authors.initials: J
authors.lastname: Buyse
authors.forename: Veerle
authors.initials: V
authors.lastname: Bruggeman
authors.forename: Eddy
authors.initials: E
authors.lastname: Decuypere
authors.forename: Sophie
authors.initials: S
authors.lastname: Tesseraud
mesh_terms: D000821:Animal Feed; D000818:Animals; D000831:Animals, Newborn; D002645:Chickens; D004044:Dietary Proteins / Q000494:pharmacology*; D004734:Energy Metabolism; D006128:Growth / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology*; D010766:Phosphorylation; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
chemical_list: D004044:Dietary Proteins; D019893:Ribosomal Protein S6 Kinases; D038744:Ribosomal Protein S6 Kinases, 90-kDa