From the sea to aquafeed: A perspective overview

Aquaculture has been one of the fastest-growing food production systems sectors for over three decades. With its growth, the demand for alternative, cheaper and high-quality feed ingredients is also increasing. Innovation investments on providing new functional feed alternatives have yielded several viable alternative raw materials. Considering all the current feed ingredients, their circular adaption in the aquafeed manufacturing industry is clearly of the utmost importance to achieve sustainable aquaculture in the near future. The use of terrestrial plant materials and animal by-products predominantly used in aquafeed ingredients puts a heavily reliance on terrestrial agroecosystems, which also has its own sustainability concerns. Therefore, the aquafeed industry needs to progress with functional and sustainable alternative raw materials for feed that must be more resilient and consistent, considering a circular perspective. In this review, we assess the current trends in using various marine organisms, ranging from microorganisms (including fungi, thraustochytrids, microalgae and bacteria) to macroalgae and macroinvertebrates as viable biological feed resources. This review focuses on the trend of circular use of resources and the development of new value chains. In this, we present a perspective of promoting novel circular economy value chains that promote the re-use of biological resources as valuable feed ingredients. Thus, we highlight some potentially important marine-derived resources that deserve further investigations for improving or addressing circular aquaculture

Deniz levreğinin (Dicentrarchus labrax) tatlısuda semirtilme olanağı

TEZ3230Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 1999.Kaynakça (s. 51-58) var.vi, 58 s. ; 30 cm.

Deniz levreği (Dicentrarchus labrax)'nin alıştırılması ve tatlısuda optimal yemleme oranının belirlenmesi

TEZ4521Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2003.Kaynakça (s. 97-111) var.vıı, 111 s. ; 30 cm.…Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi Tarafından Desteklenmiştir. Proje No:FBE.2002.D.6

Değişik tuzluluklarda ve tatlı suda yetiştirilen deniz levreğinde (Dicentrarchus labrax) büyüme performansı, vücut özellikleri ve fileto kompozisyonu

The effects of various salinities and fresh water (FW) (0.4 ppt) on the growth performance, body traits and fillet composition of juvenile and young sea bass (Dicentrarchus labrax) in FW were investigated in two separate experiments in this study. In Experiment 1, following acclimation, sea bass juveniles (9.5 $\pm$ 0.5 g) were reared in 240-L fibreglass tanks (40 x 40 x 150 cm) for 90 days in five different treatments (FW, 10, 20, 30 and 40 ppt). The fish cultured in FW, 10 and 20 ppt grew better than those at 30 or 40 ppt (P 0.05). Yet, the dry weight of the fish grown in FW was significantly lower than those reared in saline waters (P 0.05). Fish growth rates were 0.72 g day-1 in SW and 0.81 g day-1 in FW. Salinity did not significantly affect the meat crude protein, lipid or ash content (P > 0.05). Food conversion efficiency (FCE) was slightly higher in SW (77%) than in FW (74%). The mean fillet weight of the fish reared in FW was 16% higher than for SW. Fillet yields in FW and SW were 52% and 50%, respectively. From the blood plasma ions, Na+ and Cl- were lower in the fish grown in FW as compared to SW (P 0.05). Yet, the dry weight of the fish grown in FW was significantly lower than those reared in saline waters (P 0.05). Fish growth rates were 0.72 g day-1 in SW and 0.81 g day-1 in FW. Salinity did not significantly affect the meat crude protein, lipid or ash content (P > 0.05). Food conversion efficiency (FCE) was slightly higher in SW (77%) than in FW (74%). The mean fillet weight of the fish reared in FW was 16% higher than for SW. Fillet yields in FW and SW were 52% and 50%, respectively. From the blood plasma ions, Na+ and Cl- were lower in the fish grown in FW as compared to SW (P < 0.05), but K+ level did not vary between the treatments

Balık Yağına İkame Eden İki Farklı Bitkisel Yağ Sınıfının Juvenil Avrupa Deniz Levreğinde (Dicentrarchus Labrax) Besinsel Sindirime Etkileri

Bu çalışmada, balık yağı (BY) ve iki farklı bitkisel yağ (tekli doymamış yağ asitlerince zengin kolza yağı, KY ve n-6 çoklu doymamış yağ asitlerince zengin pamuk tohumu yağı; PTY) içeren yemlere tabi tutulan Avrupa deniz levreğindeki çoklu doymamış yağ asidi (PUFA)/ yüksek doymamış yağ asidi (HUFA) oranı değerlendirilmiştir. 20 adet Avrupa deniz levreği, (?35 g) 130 gün boyunca %100 balık yağı (BY), %100 rafine edilmiş kolza yağı (KY) ve %100 rafine edilmiş pamuk tohumu yağı ilave edilmiş 3 yemle beslenmiştir. Final ağırlığı, ağırlık kazancı ve spesifik büyüme oranı karşılaştırıldığında BY ve KY yemi ile beslenen balıklar PTY yemi ile beslenenlere göre önemli düzeyde daha yüksek bulunmuştur. KY ile beslenen balıklarda final ağırlığı (87,3±3,1 g), BY(84,3±1,2 g) ve PTY (80,4±2,3; P<0,05) ile beslenenlere kıyasla önemli ölçüde daha yüksek bulunmuştur. Filetodaki eikosapentaenoik asit, (EPA) ve dokosahekzaenoik Asit (DHA) yoğunluğu, yemlerdeki MUFA ve n-6 PUFA seviyelerinin artmasıyla azalmıştır. Buna göre, PTY ile beslenen balıkların DHA miktarı %9,41 iken KY (%7,93) ile beslenen balıkların kaslarındaki DHA miktarı daha düşüktür. Tahmin edildiği üzere, diyetlerdeki bireysel yağ asitlerinin emilimi zincir uzunluğu ile azalmakta ve doymamışlık derecesiyle artmaktadır. Diyetlerdeki PUFA/HUFA oranının artmasıyla görünen total yağ sindirilebilirliği azalmaktadır.This study evaluated dietary polyunsaturated fatty acid (PUFA)/highly unsaturated fatty acid (HUFA) ratios in European sea bass subjected to feeds containing fish oil (FO) or two different vegetable oils (the monounsaturated fatty acid: MUFArich rapeseed oil, RO; and the n-6 PUFA-rich cottonseed oil, CSO). Triplicate groups of twenty fish (35±0.2 g) were fed three fish-based diets in which the added lipid was 100% fish oil (FO), 100% refined low-erucic-acid-rapeseed oil (RO), 100% cottonseed oil (CSO) for a period of 130 days. As a result of this study, final weight, weight gain and specific growth rate were significantly higher in fish fed FO and RO diet compared to fish fed CSO. Final weight in fish fed the RO diet were significantly higher (87.3±3.1 g) in comparison to fish fed the FO (84.3±1.2 g) and CSO diets (80.4±2.3, <0.05). The concentration of eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) in flesh was significantly reduced with increasing levels of MUFA and n-6 PUFA in the diet. Accordingly, DHA value in fish fed the CSO diet was 9.41% whereas fish fed the RO diet had lower (7.93%) DHA content in the flesh. As expected, the absorption of individual dietary fatty acids decreased with chain length and increased with the degree of unsaturation. The apparent total lipid digestibility decreased with increasing the PUFA/HUFA ratio in the diet

Determination of Hematological Status as Health Indicator of European Sea Bass (Dicentrarchus labrax L.) Fed Different Dietary Fatty Acids

In this study, the European Sea Bass (Dicentrarchus labrax) were fed rich canola oil which is containing monounsaturated fatty acid (MUFA) and rich cottonseed oil which is containing n-6 polyunsaturated fatty acid (PUFA) and the effects of these feeds on some hematological parameters were investigated. Experimental fish were fed two times daily with 100% fish oil (FO-control), 100% cottonseed oil (CSO), 100% canola oil (CO) and 50% CSO - 50% CO (CSO50-CO50) for 162 days. End of the experiment, total erythrocyte (RBC) amount was highest in the CSO group 269.0 x (104 mm3 -1 ) compared to all other groups. Leukocyte (WBC) 96.280 x (103 mm3 -1 ), monocyte, lymphocyte and neutrophil amounts showed significant increases in only CSO group. Therefore, in terms of fish health and welfare, the exclusive use of cottonseed oil without mixing with the other vegetable oils in sea bass diet formulation can be a viable alternative to fish oil since it has the most suitable fatty acids.In this study, the European Sea Bass (Dicentrarchus labrax) were fed rich canola oil which is containing monounsaturated fatty acid (MUFA) and rich cottonseed oil which is containing n-6 polyunsaturated fatty acid (PUFA) and the effects of these feeds on some hematological parameters were investigated. Experimental fish were fed two times daily with 100% fish oil (FO-control), 100% cottonseed oil (CSO), 100% canola oil (CO) and 50% CSO - 50% CO (CSO50-CO50) for 162 days. End of the experiment, total erythrocyte (RBC) amount was highest in the CSO group 269.0 x (104 mm3 -1 ) compared to all other groups. Leukocyte (WBC) 96.280 x (103 mm3 -1 ), monocyte, lymphocyte and neutrophil amounts showed significant increases in only CSO group. Therefore, in terms of fish health and welfare, the exclusive use of cottonseed oil without mixing with the other vegetable oils in sea bass diet formulation can be a viable alternative to fish oil since it has the most suitable fatty acids

The effects of rate-restricted feeding regimes in cycles on digestive enzymes of gilthead sea-bream, Sparus aurata

In order to understand enzymatic alteration during the restricted-to-fed feeding schedules in cycles, the modulation of key enzyme activities in digestion was studied in different part of gastrointestinal track of juvenile gilthead sea bream (Sparus aurata). Juveniles (6.4 g) were stocked into 12 tanks at a density of 16 fish per tank. Four different feeding schedules were tested on triplicate groups of juvenile fish: (1) fish were fed to apparent satiation twice a day throughout 48 days, (2) starvation for 1 day and then re-fed for 2 days (S1), (3) 50% satiation for 2 days and then re-fed to apparent satiation for 2 days (R2), (4) 50% satiation for 6 days and then re-fed to apparent satiation for another 6 days (R6). The activity of total protease, amylase and lipase in the control group was higher than those S1 and R6 in whole gastrointestinal track. The restricted feeding in R2 enhanced the activities of lipase, amylase, and, to some extent, total protease in fish, with the mostly pronounced effect exhibited in the pyloric caeca. Generally, total protease and lipase activity of fish in R2 exhibited no significant difference compared to the control, except amylase activity in mid-intestine. Thus, because of preserved digestive enzyme activities, some food restriction (R2) cycles may be recommended as a routine procedure in commercial production of juvenile gilthead sea bream.In order to understand enzymatic alteration during the restricted-to-fed feeding schedules in cycles, the modulation of key enzyme activities in digestion was studied in different part of gastrointestinal track of juvenile gilthead sea bream (Sparus aurata). Juveniles (6.4 g) were stocked into 12 tanks at a density of 16 fish per tank. Four different feeding schedules were tested on triplicate groups of juvenile fish: (1) fish were fed to apparent satiation twice a day throughout 48 days, (2) starvation for 1 day and then re-fed for 2 days (S1), (3) 50% satiation for 2 days and then re-fed to apparent satiation for 2 days (R2), (4) 50% satiation for 6 days and then re-fed to apparent satiation for another 6 days (R6). The activity of total protease, amylase and lipase in the control group was higher than those S1 and R6 in whole gastrointestinal track. The restricted feeding in R2 enhanced the activities of lipase, amylase, and, to some extent, total protease in fish, with the mostly pronounced effect exhibited in the pyloric caeca. Generally, total protease and lipase activity of fish in R2 exhibited no significant difference compared to the control, except amylase activity in mid-intestine. Thus, because of preserved digestive enzyme activities, some food restriction (R2) cycles may be recommended as a routine procedure in commercial production of juvenile gilthead sea bream

Effect of feeding frequency on growth, feed efficiency and nutrient utilization of juvenile flounder (Platichthys flesus luscus)

Eroldogan, Orhan Tufan/0000-0001-6978-7524; AYDIN, ILHAN/0000-0001-8333-3852; aydin, ilhan/0000-0001-6880-4935WOS: 000332315700030An experiment was conducted to determine the effects of optimal feeding frequency on growth performance, feed efficiency, nutrient utilization and body composition in juvenile flounder. Four feeding frequencies of one (F1), two (F2), three (F3) and four (F4) times a day were evaluated as treatments in triplicate for a period of 60 days. Forty-seven hatchery produced juveniles (2.5 +/- A 0.7 g) were stocked into 160-L rectangular fiberglass tanks and fed with a commercial diet containing 54 % protein to satiation. At the end of the experiment, the final weight of F1, F2, F3 and F4 were 5.06 +/- A 0.29, 5.91 +/- A 0.42, 6.24 +/- A 0.42 and 6.16 +/- A 0.46 g, respectively. Growth rates and feed consumption were highest in F3 and lowest in F1. Feed conversion ratios ranged between 0.83 +/- A 0.04 and 0.90 +/- A 0.03. There were no significant differences in either moisture or ash content of the fish groups. Protein content decreased with increasing feeding frequency, while lipid content partly increased with increasing feeding frequency. Nitrogen intake and lipid intake were significantly higher in fish fed under F3 and F4 treatment, whereas the nitrogen gain decreased and lipid gain increased with increasing feeding frequency. It is concluded that the flounder juveniles can achieve maximum growth performance and better nutrient utilization when they are fed a given ration two times a day. the findings have practical significance toward establishing an appropriate flounder nursery rearing and will directly benefit the nursery operations.Ministry of Agriculture and Rural Affairs, the Central Fisheries Research InstituteGida Tarim ve Hayvancilik BakanligiThis study was supported by Ministry of Agriculture and Rural Affairs, the Central Fisheries Research Institute, with project entitled "Research on Rearing Possibilities of Flounder (Platichthys flesus luscus L.)"