title: Day length has a major effect on the response of protein synthesis rates to feeding in growing Japanese quail.
abstract: We investigated the effect of day length on mixed protein fractional synthesis rates (K(S)) in 14- and 21-d-old Japanese quail (Coturnix c. japonica) habituated to either a long day length, 18 h light/6 h dark (LDL), or short day length, 6 h light/18 h dark (SDL), with free access to food during the light period. Rates of protein synthesis were measured by a flooding dose of L-[1-(13)C]leucine. In both groups, we measured K(S) of pectoral muscle, liver and heart after an overnight period of food deprivation and after 2-h food access at dawn. Rates of protein synthesis were also measured in LDL quail starved for 18 h and refed for 2 h. SDL chicks were smaller and had lower tissue weights at 2 wk of age than did LDL chicks (P<0.05). Starvation led to a lower rate of protein synthesis in those animals starved for 18 h. Food availability after starvation for 18 h induced a significant rise in tissue protein synthesis in both SDL and LDL quail (P<0.05). This increase was absent in LDL quail after a 6-h starvation period. There was an increase in K(S) to ad hoc changes in food supply. By determining the daily period in which feeding can occur, day length has a major effect on protein synthesis rates. This effect will determine the overall growth chicks are able to achieve that have been subjected to different day lengths.
authors.affiliation: Zoological Laboratory, University of Groningen, Haren, the Netherlands. p.e.boon@rikilt.wag-ur.nl
authors.forename: P
authors.initials: P
authors.lastname: Boon
authors.forename: P W
authors.initials: PW
authors.lastname: Watt
authors.forename: K
authors.initials: K
authors.lastname: Smith
authors.forename: G H
authors.initials: GH
authors.lastname: Visser
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D002940:Circadian Rhythm; D003370:Coturnix / Q000254:growth & development* / Q000378:metabolism; D005247:Feeding Behavior; D005508:Food Deprivation; D007700:Kinetics; D007930:Leucine / Q000378:metabolism*; D008027:Light; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D011506:Proteins; D007930:Leucine