Poultry fat as a main fat source in a mixture to replace fish oil in diets for Oreochromis niloticus

An evaluation of the complete replacement of both fishmeal and fish oil in diets for juvenile Asian seabass, Lates calcarifer

Several reports show that aquaculture is the fastest food-producing sector globally, contributing nearly half of global fish production from all sectors. However, there has been a steady decline in production of fish oil (FO), which supports intensive aquaculture production. This has resulted in variable but generally increasing prices of FO. Finding suitable alternatives to scarce FO is essential for aquaculture sustainability. Therefore an experiment was carried out to investigate the influence of complete FO substitution with vegetable oil (VO) in the diet of Oreochromis niloticus fingerlings on growth performance, whole-body composition, and protein retention. Four isonitrogenous (30% crude protein), isolipidic (8% crude lipid), and isocalorific (17 MJ kg−1gross energy) basal diets were formulated as follows: a control diet was formulated to contain 5% FO and labeled FOD (fish oil diet), and three other diets were formulated and labeled SOD (soya oil diet), GOD (groundnut oil diet), and POD (palm oil diet); they contained soya oil (SO), groundnut oil (GO), and palm oil (PO) respectively as total replacements for FO. Triplicate O. niloticus fingerlings (N = 120, n = 10, 1.20 ± 0.03 g, mean weight ± SD) were randomly allocated to one of four experimental diets. Fish were hand-fed to apparent satiation twice daily for 63 days. The result obtained from the experiment revealed that dietary lipids significantly influenced growth performance and nutrient utilization of O. niloticus (P < 0.05). The fish fed POD had the least weight gain (WG) and highest feed conversion ratio (FCR) compared with fish fed FOD, SOD, and GOD from days 7–28 (P < 0.05). At day 35 the fish fed SOD had the highest WG (P < 0.05); fish fed GOD had the least WG. The best weekly overall growth at the end of day 56 was observed in fish fed FOD; fish fed POD had the least WG. At day 63, WG of fish fed FOD declined significantly compared to fish fed GOD, POD, and SOD, which had the best growth. At the end of the trial, the best cumulative growth in fish was observed for fish fed FO; however, there were no significant differences (P < 0.05) in WG and FCR between fish fed FOD and SOD. Survival was 100% for all treatments. Fish fed POD exhibited significantly lower levels of whole-body protein compared to fish fed FOD, SOD, and GOD. Fish fed a diet containing FO had the highest (P < 0.05) whole protein compared to diets with VO. However, no significant difference (P < 0.05) between whole-body protein of fish fed FOD and SOD was observed. Fish fed SOD had the highest (P < 0.5) body lipid compared with fish fed the FO, GO, and PO diets. In conclusion, the study has demonstrated that VO can completely replace FO in Nile tilapia diet without affecting growth performance of O. niloticus and that tilapia diet containing SO is a better alternative to FO compared to GO and PO. These findings are useful in dietary formulation to reduce feed costs without compromising tilapia fish growth.

This study evaluated the use of microalgae (Aurantiochytrium sp.) meal as a substitute for fish oil in the diet of juvenile Pacific white shrimp (Litopenaeus vannamei) reared in a clear-water system. Dietary treatments at five replacement levels (0%, 25%, 50%, 75%, 100%) were performed in triplicate. After 46 days, only a slight difference in shrimp final weight was observed among treatments (0.61 g). An increase in final weight was observed with replacement of up to 50% fish oil for microalgae meal, while the optimal percentage of replacement estimated was 44.7%. Feed conversion rate (FCR) of animals fed a diet of Aurantiochytrium sp.meal to replace up to 50% fish oil decreased, and the optimal percentage of replacement estimated was 49.3%. The fatty acids profile in shrimp muscle tissue demonstrated an increase in docosahexaenoic acid (DHA) from 10.03% to 14.28% with increased replacement of fish oil by microalgae meal in the diet. Therefore, the partial replacement of fish oil by microalgae meal resulted in improved shrimp growth and FCR, and total replacement of dietary fish oil had no negative effects on these parameters. In addition, inclusion of microalgae meal raises the level of DHA in shrimp muscle.

Effects of dietary protein source and protein–lipid source interaction on channel catfish ( Ictalurus punctatus) egg biochemical composition, egg production and quality, and fry hatching percentage and performance

Effect of using a fat mixture to replace partial to total fish oil in diets for Litopenaeus vannamei

This study evaluated biochemical responses of genetically male tilapia after replacing fish oil with plant-based oils in their diets. The sources of oils were coconut, olive, crude palm, sunflower and sesame seed. These oils were incorporated at 7% level and were used to formulate five isonitrogenous (42.5% CP) diets. In the control experiment (sixth diet) fish oil was used. Fish were reared in 1 m x 1 m x 1 m floating net-hapa. Feeing trial lasted for 12 weeks. At the end of the experiment, blood samples were collected and tested for serum protein, electrolytes and tissue lipid peroxidation. Results of the study revealed that the ratio of albumin to globulin was statistically similar (p &gt; 0.05) in all fish group examined. The results of serum electrolyte showed that olive oil treated fish recorded the highest (p &lt; 0.05) level. The amount of malondialdehyde (MDA) formed in fish tissues increased (p &lt; 0.05) in sunflower oil group by 69%, 43%, 20% and 32% in the liver, kidney, gills and heart respectively. This indicated that reactive oxygen species may be associated with the metabolism of sunflower oil leading to peroxidation of membrane lipids of the respective organs. However, this level of MDA deposition had not been associated with any negative effects on fish health. Inferences from this study conclusively support the direct use of these plant oils as total replacement for fish oil in diets of Oreochromis niloticus.

Reducing dependency on dietary fish meal (FM) and fish oil (FO) is extremely important for the sustainable development of the aquaculture industry. However, the metabolic consequences and mechanisms underlying the replacement of dietary FM and FO by terrestrial proteins (TPs) and lipids remain unclear. To reveal the effects of replacing dietary FM and/or FO on the metabolic changes, the integrated analysis of metabolomics and transcriptomics were employed to evaluate the changes in metabolites and genes of rainbow trout (Oncorhynchus mykiss) feeding different experimental diets. Four diets were formulated for the 84-day duration of the experiment: control group (FMFO), FM and vegetable oil (FMVO), terrestrial protein and FO (TPFO), and terrestrial protein and vegetable oil (TPVO). Integrated metabolomic and transcriptomic analyses revealed the significant difference in the metabolic pathways of O. mykiss among the three replacement schemes, i.e., single replacement of dietary FM by TP, single replacement of dietary FO by VO, and combined replacement of FM by TP and FO by VO. The combined replacement of FM and FO by TP and VO, respectively, disturbed immune function, energy metabolism, cellular protein biosynthesis capacity, and lipid metabolism of O. mykiss. The reduction of antioxidant capacity was only observed in individuals feeding diets with replacement of FM by TP. Furthermore, as soon as the dietary FM and/or FO were reduced, cellular protein biosynthesis ability was suppressed and accompanied by higher energy consumption in response to fluctuations of dietary quality, resulting in reduced growth performance. Interestingly, adenylosuccinate and adenosine monophosphate involved in purine metabolism were induced by both individual and combined replacement of FM and FO by TPs and lipids, respectively. It suggested that these two metabolites might be potential biomarkers for O. mykiss fed diets with reduction of FM and/or FO. This study constitutes a new understanding of the molecular and metabolic mechanisms of O. mykiss in response to the replacement of dietary FM and/or FO by TP and/or VO, respectively, and built a theoretical basis for further improvement of aquafeed formulation and sustainable development of aquaculture.

An 84-day growth trial was designed to investigate effects of dietary replacements fish oil with pork lard (PL) or rapeseed oil (RO) on growth and quality of gibel carp (Carassius auratus gibelio var. CAS III) (initial body weight: 158.2 ± 0.2 g), and responses of the fish refed fish oil (FO) diet. Three isonitrogenous (crude protein: 30%) and isolipid (crude lipid: 10%) diets were formulated containing 7.73% FO, PL or RO. Five experimental treatments including FO group (FO), PL group (PL), RO group (RO), group fed PL for 42 days and refed FO for 42 days (PL+rFO), RO and refed FO group (RO+rFO) was tested. At the end of first 42 days, the fish fed PL and RO had higher mortality than that of the control (P > 0.05). At the end of whole experiment, fish fed PL and RO showed higher plasma cortisol than FO fish (P < 0.05). RO+rFO fish showed higher lysozyme activity than RO fish (P < 0.05). Fish growth and feed utilization, composition of whole body and muscle, free amino acids, texture, off-flavour substances or sensory attributes were not affected by dietary treatments (P > 0.05). PL and RO diet decreased muscle EPA, DHA and n-3/n-6 ratio (P < 0.05), while FO-refeeding had recovery effect. It can be concluded that the replacement of FO by PL and RO does not affect the growth, feed utilization or fish tasting quality in gibel carp. Fish muscle fatty acids modified by dietary PL and RO can be recovered by refeeding with FO diet.

Influence of different lipid sources on growth performance, oxidation resistance and fatty acid profiles of juvenile swimming crab, Portunus trituberculatus

A 10-week feeding trial was conducted to evaluate the effects of dietary replacement of fish oil (FO) with black soldier fly larvae oil (BSFLO) and vegetable oils, namely moringa oil (MO), black cumin seed oil (BCSO) and flax seed oil (FSO) on growth and whole-body fatty acid profile, digestive enzyme activity, haemato-biochemical responses and muscle growth-related gene expression of juvenile striped catfish, Pangasianodon hypophthalmus. Five isonitrogenous (313.34 g kg−1) and isolipidic (81.82 g kg−1) experimental diets were formulated. A total of 450 fingerlings (5.02 ± 0.1 g per fish) were randomly distributed into 15 tanks and fed thrice a day. The final weight gain was significantly improved in fish fed FO (45.7 ± 0.72 g/fish), BSFLO (45.53 ± 1.32 g/fish) and MO diet (47.2 ± 0.26 g/fish) when compared to BCSO (36.3 ± 1.05 g/fish) and FSO (35.83 ± 0.71g/ fish) diets. The lower value of daily weight gain was recorded in the FSO and BCSO treatments compared with other oils could be due to effects on stress resistance and immunosuppression in fish, whereas the whole-body EPA and DHA content of fish fed with FSO and FO diets was substantially higher than fish fed with other experimental diets. However, the relative expression of Myo D and Myogenin was upregulated in fish fed with FO, BSFLO and MO diet than the BCSO and FSO diet. Present results indicate that the juveniles can be reared on diets in which FO has been replaced with BSFLO and MO, with no significant effects on fish performance.

This experiment was conducted to evaluate the effects of dietary lipid sources on growth, survival and body composition of 40 day post hatch larval grouper, Epinephelus coioides. Fish were fed fish meal and protein hydrolysate based diets for 32 days with either 100% maize oil or 100% fish oil in triplicate from 40-day after hatching to slaughter size (fish weight: 0.32 g to 11 g). Final body wet weight (FBW: 11.8±0.7 and 11.1±0.1, respectively), weight gain (WG: 3556±251 and 3360±189, respectively), specific growth rate (SGR: 11.2±0.2 and 11.1±0.2, respectively) and survival rate (80±5 and 79±4, respectively) were not significantly affected by dietary lipid sources (P>0.05). The effect of different oil sources on the composition of tissues was significant only for dorsal muscle lipid. In dorsal muscle, lipid content was significantly higher in fish oil group. The fatty acids composition of the muscle lipids well reflected the fatty acids composition of the experimental diets. The growth performance showed that a balance is required between growth-promoting essential fatty acids (EFA) qualities of dietary n-3 highly unsaturated fatty acid (n-3 HUFA) and their potentially growth-inhibiting (pro-oxidant) qualities. Results indicated when EFA of the diet are sufficient for the development of postlarvae, there is no difference whether use fish or maize oil in the formulated diets, 2.87% n-3 HUFA is sufficient for grouper postlarvae development and more n-3 HUFA are not necessarily beneficial to fish performance.

Nutritional intervention through dietary vegetable proteins and lipids to gilthead sea bream (Sparus aurata) broodstock affects the offspring utilization of a low fishmeal/fish oil diet

BackgroundThe finite marine resources make it difficult for us to obtain enough fish oil (FO) used in aquatic feeds. Another sustainable ingredients should be found to substitute FO. The effects of replacing FO with vegetable oil have been studied in a variety of crustaceans, but most studies have focused on the phenotypic effects. Little is known about the mechanisms of the effects.MethodsTo understand the molecular responses during the replacement of FO in Eriocheir sinensis, we investigated the effects of feeding FO or linseed oil (LO) on growth performance, digestive enzyme activity, fatty acid composition and protein expression in E. sinensis. Twenty-four juvenile crabs were fed diets containing FO or LO for 112 days. Weight, carapace length and width were recorded. Fatty acid composition of the diets and the hepatopancreas and protein expression in the hepatopancreas were analyzed.ResultsGrowth performance and molting interval were unchanged by diet. Crabs fed FO and LO had same activity of lipase and amylase, but comparing with crabs fed LO, crabs fed FO had higher trypsin activity and lower pepsin activity. Hepatopancreas fatty acid composition changed to reflect the fatty acid composition of the diets. In total, 194 proteins were differentially expressed in the hepatopancreas between the diets. Expression of heat shock proteins was higher in crabs fed LO. Expression of fatty acid synthase, long-chain fatty acid transport protein 4, acyl-CoA delta-9 desaturase, and fatty acid-binding protein 1, was higher in crabs fed FO.ConclusionsThe substitution of FO with LO didn’t have any effects on the growth and molting of mitten crab, but could significantly decrease the ability of mitten crab to cope with stress. The high content of HUFAs in the hepatopancreas of mitten crab fed FO is due to the high abundance of the proteins relative to the transport of the HUFAs. These findings provide a reason of the high content of EPA and DHA in crabs fed with FO, and provide new information for the replacement of FO in diets of mitten crab.

Five iso-nitrogenous (crude protein 32 %) and iso-energetic (gross energy 15 MJ kg−1) practical diets were formulated by totally replacing fish oil (FO) with soybean oil (SO), rapeseed oil (RO), linseed oil (LO) and pork lard (PL), respectively. These diets were fed to triplicate groups of 30 gift tilapia (Oreochromis niloticus) (mean initial weight 9 g). Fish were fed three times a day for 8 weeks at 26.5 ± 2.5 °C. The results showed that the replacement of FO with RO or LO or PL in tilapia diets did not affect growth or feed utilization. Fish fed SO exhibited lower specific growth rate and protein efficiency ratio, and higher feed conversion ratio. The lowest hepatosomatic index, hepatopancreas lipid content, hepatopancreas malondialdehyde contents, lipoprotein lipase and malate dehydrogenase activities in liver were observed in fish fed FO, LO and RO. Fish fed FO or LO exhibited higher aspartate transaminase and alanine transaminase activities in liver and higher total antioxidant capacity, superoxide dismutase and alkaline phosphatase activities in serum, but the values of these parameters were lower in fish fed PL in comparison with the other groups. This study showed that alternative lipid sources could be used successfully in tilapia diets except for SO. Total replacement of dietary fish oil by linseed oil could be possible without adverse effects on fish health.

Simple SummaryOne of the main concerns in aquaculture is the overreliance on wild-sourced fish oil as the main source of omega-3 fatty acids in diets for farmed fish. Microbes, such as Schizochytrium, naturally produce high levels of omega-3 fatty acids that could potentially replace fish oil in aquaculture feeds. In this study, we tested the oil from a new strain of Schizochytrium (T18) to replace fish oil in diets for farmed rainbow trout and looked at fish growth performance, muscle and liver fatty acid content, and the expression of transcripts involved in fat metabolism. Trout were raised for 8 weeks and fed diets with either: (1) fish oil control, (2) low inclusion of microbial oil, or (3) higher inclusion of microbial oil. Inclusion of Schizochytrium sp. (T18) oil at high or low levels in the diet resulted in a similar growth performance as seen in trout fed the control diet; however, muscle and liver fatty acid profiles were impacted by diet. Overall, our results showed that Schizochytrium (T18) is an effective source of omega-3 fatty acids in diets for rainbow trout.In this study, we evaluated whether oil extracted from the marine microbe, Schizochytrium sp. (strain T18), with high levels of docosahexaenoic acid (DHA), could replace fish oil (FO) in diets for rainbow trout (Oncorhynchus mykiss). Three experimental diets were tested: (1) a control diet with fish oil (FO diet), (2) a microbial oil (MO) diet with a blend of camelina oil (CO) referred to as MO/CO diet, and (3) a MO diet (at a higher inclusion level). Rainbow trout (18.8 ± 2.9 g fish−1 initial weight ± SD) were fed for 8 weeks and evaluated for growth performance, fatty acid content and transcript expression of lipid-related genes in liver and muscle. There were no differences in growth performance measurements among treatments. In liver and muscle, eicosapentaenoic acid (EPA) was highest in trout fed the FO diet compared to the MO/CO and MO diets. Liver DHA was highest in trout fed the MO/CO diet compared to the FO and MO diets. Muscle DHA was highest in trout fed the MO and MO/CO diets compared to the FO diet. In trout fed the MO/CO diet, compared to the MO diet, fadsd6b was higher in both liver and muscle. In trout fed the FO or MO/CO diets, compared to the MO diet, cox1a was higher in both liver and muscle, cpt1b1a was higher in liver and cpt1a1a, cpt1a1b and cpt1a2a were higher in muscle. Schizochytrium sp. (T18) oil was an effective source of DHA for rainbow trout.