Understanding the Interaction Effects between Dietary Lipid Content and Rearing Temperature on Growth Performance, Feed Utilization, and Fat Deposition of Sea Bass (Dicentrarchus labrax)

This study was conducted to elucidate the interaction effects of temperature and dietary lipid levels (2 × 2 factorial experiment) on the growth performance, muscle, and liver composition in adult farmed European sea bass (Dicentrarchus labrax). Two groups of fish (190 g; 60 fish per group) were distributed in 12 tanks in triplicates and kept at two different temperature regimes; one starting at 23 °C and then changed to 17 °C for 61 days, and the other starting at 17 °C and then changed to 23 °C for 39 days. Two commercial diets containing both ~44% crude protein but incorporating different dietary lipid levels, 16.5% (D16) and 20.0% (D20) (dry matter (DM)), were fed to the fish to apparent satiation; the type of diet fed to each fish group remained constant throughout the experiment. Final body weight, weight gain, and specific growth rate were significantly higher for the fish group held at 23 °C compared to the fish group at 17 °C (before the temperature changes), while the dietary fat content did not have any profound effect in both groups. Furthermore, the different temperature regimes did not affect muscle or liver composition, but, on the contrary, dietary lipids affected hepatosomatic, perivisceral fat, and visceral indexes. Feed conversion ratio and specific growth rate were not affected by the dietary lipid level. An interaction of temperature and dietary lipid content was observed in daily feed consumption (DFC) and final body weight (FBW).info:eu-repo/semantics/publishedVersio

Dietary Tenebrio molitor Larvae Meal Inclusion Exerts Tissue-Specific Effects on Cellular, Metabolic, and Antioxidant Status in European Sea Bass (Dicentrarchus labrax) and Gilthead Seabream (Sparus aurata)

The present study addresses the effects of dietary Tenebrio molitor (TM) larvae meal inclusion on cytoprotective, cell death pathways, antioxidant defence, and intermediate metabolism in the heart, muscle, and digestive tract of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax). Three experimental diets were formulated to contain 0%, 25%, or 50% inclusion TM levels. Heat Shock Proteins (HSPs) induction was apparent in both species’ muscle at 50% inclusion. Conversely, p44/42 Mitogen-Activated Protein Kinase (MAPK) activation was increased () in both species’ muscle and digestive tract at 25% inclusion. Regarding the apoptotic machinery, TM inclusion exerted no influence on gilthead seabream, while suppression through autophagy may have occurred in the muscle. However, significant apoptosis () was evident in European sea bass muscle and digestive tract. Both fish species’ heart seemed to additionally rely on lipids compared to muscle and digestive tract. In contrast to gilthead seabream, European sea bass exhibited increased () antioxidant activity at 50% TM inclusion. The present findings highlight the dietary derived induction of cellular responses in a species- and tissue-specific manner, whereas European sea bass appears to be more susceptible to TM inclusion

Tenebrio molitor larvae meal inclusion affects hepatic proteome and apoptosis and/or autophagy of three farmed fish species

Acknowledgements Financial support for the trial on European sea bass was provided by the AQUAEXEL Project PROINSECTLIFE (Ref. No. 0013/03/05/15B), the AQUAEXEL Project INDIFISH (Ref. No. 0125/08/05/15/TNA), and by the University of Turin (ex 60%) Grant (Es. fn. 2014). NP (Scholarship Code: 1752) has been fnancially supported by the General Secretariat for Research and Technology (GSRT) of Greece and the Hellenic Foundation for Research and Innovation (HFRI) and MM by the Operational Programme “Human Resources Development, Education and Lifelong Learning” in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research” (MIS-5000432) as implemented by the State Scholarships Foundation (ΙΚΥ). Tanks to Evelyn Argo and Craig Pattinson (University of Aberdeen) for providing help with 2DE. EM was fnancially supported by Marine Alliance for Science and Technology Scotland (MASTS) visiting Fellowship.Peer reviewedPublisher PD

Effect of Citric Acid on Growth and Red Coloration of Red Porgy (Pagrus pagrus)

This study investigates the effect of dietary citric acid supplementation on the growth and red coloration of red porgy (Pagrus pagrus). Red porgy (~0.5 g) were fed one of four diets: (a) an unsupplemented control, (b) a diet containing astaxanthin at 0.06 g/kg, (c) a diet containing citric acid at 30 g/kg, or (d) a diet containing both astaxanthin at 0.06 g/kg and citric acid at 30 g/kg. After two months, fish reached ~6 g with no differences in growth between groups. Astaxanthin increased the total carotenoid concentration in the skin from 3.16 to 45.15 μg/g in fish fed the astaxanthin-supplemented diet and from 2.61 to 50.07 μg/g in fish fed the diet supplemented by both astaxanthin and citric acid, producing a distinctive red skin color. Diet composition did not affect the melanin concentration of the skin, which ranged 57.60-68.18 μg/g and did not differ between groups. Dietary supplementation of citric acid did not affect growth or coloration in red porgy, thus alternative means of administering citric acid should be sought, for example, adding citric acid to the rearing water or injecting it into the fish body

Evaluation of Feed Stimulants in Diets for Sea Bream (Sparus aurata)

Six isoprotein and isolipidic diets were formulated to investigate the effect of dietary additives on growth and feed efficiency of sea bream (Sparus aura- ta) fry fed a fishmeal-based diet for 80 days. The additives (protorsan, hydrolyzed fish protein, squid meal, krill meal, and betaine + inosine-5’- monophosphate) were added to the diets at the expense of fishmeal. The specific growth rates of the fish ranged from 2.17-2.18% per day for the pro- torsan and control groups to 2.42% per day for the group fed the squid addi- tive. Significant differences (p0.05) between treatments. The feed stimulating action of taurine was tested by observation. Pellets coated in a taurine solution were more actively consumed than control pellets during the morning feeding but consumption did not differ during the afternoon feeding

Effects of Dietary Lecithin, Nucleoside, and Krill Supplementation to a Fishmeal Based Diet on Growth and Feed Utilization of Sharpsnout Sea Bream (Diplodus Puntazzo)

The aim of this 96 day feeding trial was to investigate the effects of the addition of different combinations of dietary lecithin, nucleosides, and krill to a fishmeal-based diet on the growth, feed utilization, feed consumption, and body composition of sharpsnout sea bream (Diplodus puntazzo). Six hundred (600) fish (average weight 21.21 ± 0.06SD g) were divided into 8 groups (triplicate treatments) and fed eight isoenergetic fishmeal-based diets, (C-control, L-lecithin, N-nucleosides, K-krill, L+N-lecithin+nucleosides, N+K-nucleosides+krill, L+K-lecithin+krill, L+N+K-lecithin+nucleosides+krill). The effects of the dietary regimes were evaluated in terms of specific growth rate (SGR), feed conversion ratio (FCR), daily feed intake (DFI), and whole body chemical composition (moisture, crude ash, crude protein and crude lipid). At the end the trial the fish had tripled their initial weight. SGR, FCR and DFI were 1.17-1.24 %, 0.95-1.01, and 1.03-1.14% respectively. Although differences were observed between some groups, none of the tested feed additives improved SGR, FCR, and DFI, compared to the control diet. Analysis of whole body proximate composition showed that moisture, crude ash, crude protein, and crude lipid ranged 61.45-64.00%, 3.96-4.26%, 15.44-17.26% and 14.87-18.82% respectively. Crude lipid concentration was higher in whole body of fish fed the nucleoside supplemented diet compared to control, lecithin, and krill groups. No other effects of the dietary regime on the whole body composition of sharpshout sea bream were observed