Dietary lipid level affects growth performance and nutrient utilisation of Senegalese sole ( Solea senegalensis) juveniles.
Over the last few years, several aspects of Senegalese sole (Solea senegalensis) culture have been developed and optimised but the dietary lipid level for optimal growth has never been determined. Hence, five isonitrogenous diets (56 % dietary protein) with increasing dietary lipid levels (4, 8, 12, 16 and 20 % DM) were fed to satiation to triplicate groups of twenty fish (mean initial weight 10 g). Fifteen tanks were randomly assigned one of the five diets. Feed was distributed using automatic feeders, and fish were fed over a 16-week period. At the end of the experiment the fish fed on diets containing the two lowest dietary lipid levels (4 and 8 %) showed a 3-fold body-weight increase with a significantly higher daily growth index than fish fed higher lipid levels (1.2 v. 0.8). Moreover, these fish displayed a significantly lower dry feed intake (12 g/kg per d) and feed conversion ratio (1.0) compared with fish fed higher lipids levels (16-19 g/kg per d; feed conversion ratio 2.0). Low dietary lipid levels ( < 12 %) significantly improved nutrient retention and gain and hence growth, without major effects on whole-body composition. Despite the slight alteration in n-3 PUFA muscle content in the fish fed low-fat-diets, this fish fed low dietary lipid still remains a rich n-3 PUFA product and generally maintained its nutritional value. These results evidenced a low lipid tolerance of Senegalese sole juveniles and suggest a maximal dietary inclusion level of 8 % lipids for both optimal growth and nutrient utilisation without compromising flesh quality.
Borges
Pedro
P
CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental and ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Portugal.
Oliveira
Beatriz
B
Casal
Susana
S
Dias
Jorge
J
Conceição
Luis
L
Valente
Luísa M P
LM
D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D017756:Aquaculture / Q000379:methods; D001823:Body Composition / Q000187:drug effects; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D004435:Eating / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D005412:Flatfishes / Q000254:growth & development / Q000502:physiology*; D006128:Growth / Q000187:drug effects*; D050356:Lipid Metabolism / Q000187:drug effects; D018482:Muscle, Skeletal / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
D004041:Dietary Fats; D005227:Fatty Acids