Performance of juvenile turbot (Scophthalmus maximus) fed varying dietary L-carnitine levels at different stocking densities

Authors

  • José Fernando Magalhães Gonçalves CIMAR; Centro Interdisciplinar de Investigação Marinha e Ambiental
  • Bruno Graziano da Silva Turini Universidade do Porto; Instituto de Ciências Biomédicas de Abel Salazar
  • Rodrigo Otávio de Almeida Ozório CIMAR; Centro Interdisciplinar de Investigação Marinha e Ambiental

DOI:

https://doi.org/10.1590/S0103-90162010000200004

Keywords:

compensatory growth, feed additives, stress, husbandry, nitrogen excretion

Abstract

Commercial farming of turbot (Scophthalmus maximus) at high stocking densities may lead to growth depression and increasing production costs. Moreover, the high levels of accumulated waste in an intensive system may cause rapid deterioration of water quality, which may undermine the production. L-carnitine is known as a growth-enhancer which shows promise as mitigator of crowding effects. The effects of stocking densities (4, 8, 11 and 14 kg m²) on growth performance, feed utilization and body composition were evaluated during 75 days on turbot (75.6 ± 2.8 g) fed two dietary L-carnitine levels (40 or 240 mg kg¹). At the end of the feeding trial, total ammonia excretion (TAN) was measured postprandially for 24h. Specific growth rate and weight gain decreased with increasing stocking density. Fish held at 4 kg m² had higher final body weight (94-96 g) than fish held at higher densities (80-87 g). Protein efficiency ratio was higher in fish held at 4 kg m² (1.33-1.36), in comparison to fish stocked at 8 kg m² (0.98) or 14 kg m² (0.45). Voluntary feed intake decreased from 0.70 to 0.56% BW with increasing stocking density. Dietary L-carnitine supplementation did not affect growth performance and body composition, except for body L-carnitine content which increased from 75 to 128 mg kg¹ BW with supplementation. Fish fed 240 mg L-carnitine supplements had lower TAN that the ones fed 40 mg L-carnitine (p < 0.05).

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Published

2010-04-01

Issue

Section

Animal Science and Pastures

How to Cite

Performance of juvenile turbot (Scophthalmus maximus) fed varying dietary L-carnitine levels at different stocking densities . (2010). Scientia Agricola, 67(2), 151-157. https://doi.org/10.1590/S0103-90162010000200004