Fish meals are currently the main ingredients in the diets for carnivorous fish species, due to their high protein requirements [1]. However, there are serious doubts about the economic, biological and ecological sustainability of their use in aquaculture. A class of alternative protein sources could be represented by insect meals, and in particular by insect larvae meals that for their chemical composition, more closely match the nutritional requirements of fish species [2]. Tenebrio molitor (mealworm beetle), is a coleopter belonging to the family Tenebrionidae. The aim of the study was to evaluate the effect of the inclusion of Tenebrio molitor larvae meal (TM) in practical diets for gilthead sea bream (Sparus aurata) juveniles on growth and feed efficiency. The trial was carried out in an indoor water recirculating system using 207 gilthead sea bream (45 g average initial body weight) randomly distributed in 9 fiberglass tanks. Three isoenergetic and isoproteic diets (Total lipid 19%; crude protein 44%; Gross energy, 23 MJ kg–1) were formulated: a control diet (FM), in which 999” fish meal was the sole protein source; TM25 and TM 50 diets in which 25% and 50% of fish meal protein was replaced by Tenebrio molitor larvae meal. Each diet was experimentally tested in triplicate. Fish were daily hand-fed twice a day (9:00 and 16:00) to visual satiety. The water temperature ranged between 21-23 °C. The trial lasted 60 days and at the end fish were group weighted. For each experimental group, weight gain (WG), daily intake rate (DIR), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER) were determined. The whole body composition of 6 pooled fish per replicate group were analysed for proximate composition. The results showed that up to 25%, the inclusion of TM meal in diet did not lead to adverse effects on WG and final weight, while a slight depression was observed for PER and FCR. TM 50 induced growth reduction and less favourable outcomes for SGR, FCR and PER. The whole body proximate composition analysis did not show any differences between treatments. These results showed that the substitution of fish meal protein in diets for gilthead sea bream juveniles is feasible up to 25% without adverse effects on growth performance and whole body proximate composition.
Use of Tenebrio molitor larvae meal in diets for Gilthead seabream Sparus aurata juveniles.
GASCO, Laura;
2014-01-01
Abstract
Fish meals are currently the main ingredients in the diets for carnivorous fish species, due to their high protein requirements [1]. However, there are serious doubts about the economic, biological and ecological sustainability of their use in aquaculture. A class of alternative protein sources could be represented by insect meals, and in particular by insect larvae meals that for their chemical composition, more closely match the nutritional requirements of fish species [2]. Tenebrio molitor (mealworm beetle), is a coleopter belonging to the family Tenebrionidae. The aim of the study was to evaluate the effect of the inclusion of Tenebrio molitor larvae meal (TM) in practical diets for gilthead sea bream (Sparus aurata) juveniles on growth and feed efficiency. The trial was carried out in an indoor water recirculating system using 207 gilthead sea bream (45 g average initial body weight) randomly distributed in 9 fiberglass tanks. Three isoenergetic and isoproteic diets (Total lipid 19%; crude protein 44%; Gross energy, 23 MJ kg–1) were formulated: a control diet (FM), in which 999” fish meal was the sole protein source; TM25 and TM 50 diets in which 25% and 50% of fish meal protein was replaced by Tenebrio molitor larvae meal. Each diet was experimentally tested in triplicate. Fish were daily hand-fed twice a day (9:00 and 16:00) to visual satiety. The water temperature ranged between 21-23 °C. The trial lasted 60 days and at the end fish were group weighted. For each experimental group, weight gain (WG), daily intake rate (DIR), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER) were determined. The whole body composition of 6 pooled fish per replicate group were analysed for proximate composition. The results showed that up to 25%, the inclusion of TM meal in diet did not lead to adverse effects on WG and final weight, while a slight depression was observed for PER and FCR. TM 50 induced growth reduction and less favourable outcomes for SGR, FCR and PER. The whole body proximate composition analysis did not show any differences between treatments. These results showed that the substitution of fish meal protein in diets for gilthead sea bream juveniles is feasible up to 25% without adverse effects on growth performance and whole body proximate composition.
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