Aquaculture and Fisheries Group, Wageningen Institute of Animal Sciences, Wageningen University, Wageningen, The Netherlands.
PLoS One. 2012;7(4):e34743. doi: 10.1371/journal.pone.0034743. Epub 2012 Apr 9.
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 (P<0.05). Regardless of dietary P/E ratio, the inclusion of carbohydrate compared to fat as main NPE source reduced DEI and growth of trout by ~20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). 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.
假设进行了测试，即让吃饱的鱼摄入不同宏量营养素组成的等能量饮食，它们将具有不同的可消化能摄入量（DEI），但总热量产生相似。设计了四种等能量饮食（2×2 析因设计），在 i）蛋白质与能量的比例（P/E）：高（H(P/E)）与低（L(P/E)）和 ii）非蛋白质能量（NPE）来源的类型之间存在差异：脂肪与碳水化合物，它们在能量上是等交换的。三组（每组 35 条鱼/缸）虹鳟鱼在非限制水氧条件下，每天两次手喂每种饮食至饱食，持续 6 周。鱼的摄食量（FI）、可消化能摄入量（kJ kg(-0.8) d(-1))和生长（g kg(-0.8) d(-1))受到饮食 P/E 比和 NPE 来源之间相互作用的影响（P<0.05）。无论饮食 P/E 比如何，与脂肪相比，将碳水化合物作为主要 NPE 来源包含在内，会使鱼的 DEI 和生长减少约 20%。饮食引起的 FI 和 DEI 差异表明，鱼不会补偿可消化能量或可消化蛋白质含量的饮食差异。此外，体脂肪储存和血浆葡萄糖的变化似乎不会对 DEI 产生稳态反馈控制。独立于饮食组成，鱼的热量产生没有差异（P>0.05）。我们的数据表明，鱼的 DEI 控制可能是热量产生的功能，这反过来可能反映了与氧化代谢相关的生理限制。
