PLoS ONE (Jan 2012)

Constraints on energy intake in fish: the link between diet composition, energy metabolism, and energy intake in rainbow trout.

  • Subramanian Saravanan,
  • Johan W Schrama,
  • A Claudia Figueiredo-Silva,
  • Sadasivam J Kaushik,
  • Johan A J Verreth,
  • Inge Geurden

DOI
https://doi.org/10.1371/journal.pone.0034743
Journal volume & issue
Vol. 7, no. 4
p. e34743

Abstract

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The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2 × 2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (H(P/E)) vs. low (L(P/E)) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg(-0.8) d(-1)) and growth (g kg(-0.8) d(-1)) of trout were affected by the interaction between P/E ratio and NPE source of the diet (P0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism.