Protein and Energy Metabolism of European Seabass (Dicentrarchus labrax) Juveniles and Estimation of Maintenance Requirements

Abstract

The present work aimed to study metabolic utilization of energy and protein by juvenile European seabass reared at 25°C and to estimate maintenance requirements, based on indirect calorimetry and nitrogen excretion measurements. Duplicate groups of fish (IBW=22 g) were fed a practical diet, for 28 days, at ration levels of 0, 0.25, 0.5, 1 and 1.5% of body weight. At the end of this period, oxygen consumption and ammonia nitrogen excretion were measured in fed and unfed fish. Weight gain linearly increased with ration level. Feed efficiency significantly increased with nitrogen intake up to 0.68 g N/kg/day. Nitrogen retention (% N intake) was positive at all feeding levels, being maximum at 0.5% BW and then decreased with increasing ration levels. There was negative energy balance at the lowest ration level and significantly increased at higher ration levels. Daily oxygen consumption (g/kg body mass) and ammonia excretion (mg N-NH 4 /kg body mass) significantly increased with ration level. Heat production and heat increment of feeding (kJ/kg/day) remained low at low ration levels and significantly increased as ration level increased from 0.5 to 1.5% BW. Below maintenance, protein energy represented 34% of total energy expenditure and significantly increased to 49-56% above maintenance. Based on indirect calorimetry and ammonia excretion data, maintenance energy and protein requirements were estimated to be 56.8 kJ DE/kg/day and 1.15 g DP/kg/day, respectively. The efficiencies of energy and protein utilization were estimated to be 0.83 and 0.66, respectively.

Blood chemistry profile as indicator of nutritional status in European seabass (Dicentrarchus labrax)

“…Thus, hepatic energy reserves provide a good indication of the overall nutritional condition status of seabass. Similar results were previously described in this species (Peres and Oliva-Teles 2005;Perez-Jimenez et al 2007) and in sea bream .…”

Evaluation of Protein Levels in Diets for Salema Porgy (<i>Sarpa salpa</i>) Juveniles, a New Candidate Species for the Mediterranean Aquaculture

“…This finding was also supported by the PERs in the present study with better protein utilization when fed diets lower than 40% protein. The findings in this study regarding nitrogen retention rates per intake (37-42%) in best performing protein groups are in close agreement with earlier reports in European seabass fed different ration levels (36-43%) [50], in rainbow trout (18-46%) [51], Atlantic turbot (28-36% and 36-42%) [52,53], the Black Sea turbot (38-40%, 19-41%, and 29-30%) [54][55][56]. Lower retention rate of nitrogen per intake have been reported in Blackfin seabream (20-40%) [31], zebra seabream (19-26%) [22], European seabass (23-32% and 16-26%) [57,58].…”

Effect of ration size on growth, body composition, and energy and protein maintenance requirement of fingerling Indian major carp, Labeo rohita (Hamilton)

“…As food availability increases, the quantity consumed by the fish will also increase, giving a linear increase in specific growth rate (SGR%) up to the point of maximum voluntary food intake. Growth rate is linearly correlated to food intake (Peres and Oliva-Teles 2005). If fish are fed above their appetite, the extra food will be wasted and an artificially high FCR will result.…”