Effect of isoenergetic diets with different protein and lipid content on the growth performance and heat increment of rainbow trout

摘要: Abstract The heat increment of feeding (HiE) is the metabolic cost associated with feeding, typically measured in fish as increase oxygen consumption (MO2) over some estimate standard rate (SMR). present study sought to accurately measure HiE using a variety different methods order remove influence routine activity and excitement which could overestimate HiE. Protein handling makes up large component Thus, there an expectation that variations dietary protein content Therefore, growth performance parameters were assessed juvenile rainbow trout fed daily satiation one three isoenergetic diets equivalent carbohydrate (12%) but variable (P) lipid (L) [theoretical protein:lipid levels were: 55%:10% (HP:LL); 45%:15% (MP:ML) 35%:20% (LP:HL)]. estimated digestible (DP) energy (DE) ratios 19.8, 24.8 29.8 g/MJ bracketed recommended 22–25 g/MJ for trout. values same groups maintained on test after trial subsequently following single meal (by gavage) 2% their body mass so be compared estimates. Some (i.e., specific rate, feed efficiency dry intake) did not vary significantly among diets, whereas percent deposition was inversely related DP DE ratio. dissimilar diet treatments result differences SMR, RMR, peak MO2 or time-to-peak estimates mean SMR from all combined across 50.4 ± 3.4 mg O2/kg/h. increased above by 4-h postprandial peaked at 116.2 ± 7.7 mg O2/kg/h, representing 131%. (as % DE) low, best ranged between 4.0 4.8%.