Aquaculture Nutrition最新文献

This study investigated the effect of adding the compound acidifiers on the intestine health of hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) fed diet with higher cottonseed protein concentrate (CPC). To assess the benefits of compound acidifiers helping CPC to replace more fish meal (FM) for hybrid grouper, five isonitrogen and isolipid experimental diets were formulated. The five diets consisted of a control diet (FM, 50%) and four experimental diets (27.5% FM, 27.27% CPC), each of which contained compound acidifiers to varying degrees (FCA0, FCA0.05, FCA0.1, and FCA0.2). Each diet was fed to three replicates of each group for 8 weeks. In the FCA0.05 group, the results demonstrated a statistically significant increase in protein efficiency ratio, lipid efficiency ratio, and the activity of digestive enzymes in the intestine (P < 0.05). In the FCA0.05 group, there was a clearly enhanced expression of anti-inflammatory cytokines in the intestines (P < 0.05). In the FCA0.1 group, there may be an increase in the expression of important genes involved in fatty acid metabolism in the intestinal (P < 0.05). Appropriate compound acidifiers decreased the relative abundance of Vibrio and other harmful bacteria in the intestine flora that were brought by high CPC. In conclusion, when the hybrid grouper was given a diet containing more CPC, the FCA0.05 group was able to promote intestinal development, enhance digestive enzyme activity and feed consumption, raise antioxidant enzyme activity and anti-inflammatory factor expression, and improve intestinal health.

This study aimed to investigate the effects of replacing inorganic trace minerals (ITM) with organic trace minerals (OTM) on growth performance, body composition, gut histomorphometry, digestive enzyme activity, apparent digestibility coefficients (ADC), and mineral balance in juvenile Nile tilapia, Oreochromis niloticus. Fish (n = 432; 2.5 ± 0.5 g) were randomly distributed into four groups with four replicates each (27 fish per replicate). A control diet (gross 15.2 MJ gross energy kg⁻¹; 367.3 g crude protein kg⁻¹) was elaborated to meet the dietary requirements of zinc (Zn), manganese (Mn), and copper (Cu) using ITM in the sulfate form (ITM100). From the control diet, three diets were elaborated using OTM to supply 100% (OTM100), 75% (OTM75), and 50% (OTM50) of Zn, Mn, and Cu ITM of the control diet, respectively, supplied in the glycinate form. Fish were hand-fed six times daily for 8 weeks. Growth performance was not changed by dietary treatments. Fish fed on the diet OTM50 showed higher whole-body and vertebrae ash contents and higher whole-body calcium (Ca), Zn, and iron (Fe) retention than those fed on the control diet. The activity of digestive enzymes and the ADC of energy and nutrients, including Zn, Mn, and Cu, were similar in fish fed on diets OTM50 and ITM100. A reduction in Zn (−39.8%), Mn (−11.1%), and Cu (−14.0%) loss was observed in fish fed on the diet OTM50 than in fish fed diet ITM100. The dietary treatments did not affect the gut histomorphometry. In conclusion, the inclusion of OTM in Nile tilapia’s diets represents a promising strategy to reduce 50% of ITM sources by utilizing Zn, Mn, and Cu OTM as glycinates without detrimental effects on growth performance, nutrient utilization, and gut function. These results additionally reinforce the environmental benefits of using OTM for precise mineral nutrition in aquaculture.

The present study aims to evaluate the effect of liquid fish protein hydrolysate (FPH) following fishmeal substitution with full-fat and defatted BSF (black soldier fly, Hermetia illucens) meal in the feeds of juvenile ornate spiny lobster, Panulirus ornatus. The physiological aspects of juvenile lobsters including growth, fatty acids profile, and histopathology were observed. Six isoenergetic experimental feeds having a protein-to-energy ratio of 26 CP mg kJ⁻¹ were formulated with the substitution of fishmeal at 25% using liquid FPH, full-fat BSF (FBSF), defatted BSF (DBSF), and their combination. The specific growth rate, final body weight, final total length, and length increment of juvenile lobsters (initial weight was 0.21 ± 0.01 g and total length was 20.53 ± 0.12 mm) were significantly affected by the fishmeal substitution (P  < 0.05) and improved with the addition of liquid FPH in the feeds containing FBSF and DBSF. The whole body proximate analysis showed that the liquid FPH to the feeds containing DBSF increased the ash and protein content significantly (P  < 0.05). The total monounsaturated fatty acids (∑MUFA), saturated fatty acids (∑SFA), and omega 9 fatty acids (∑n−9 FA) of juvenile lobsters’ whole bodies fed with dietary DBSF and FPH supplementation were significantly higher than those of others (P  < 0.05). The histopathological analysis indicated that the villus size and the muscle thickness in the intestine were not significantly affected by FPH supplementation. However, the hepatopancreas histopathology indicated the presence of B-cells and R-cells in the juvenile lobsters fed with FPH-supplemented feeds. The present results suggested the supplementation of liquid FPH to the formulated feed with FBSF and DBSF for juvenile lobsters can improve the lobsters’ growth and fatty acids availability.

Herbal extracts have been successfully used as feed additives in fish culture with attractive growth-promoting, immunostimulant, antimicrobial, and antioxidant properties for several fish and shellfish species. Therefore, we have designed a feeding trial to assess the impacts of dietary incorporation of Perovskia abrotanoides extract (PAE) on common carp (Cyprinus carpio). For this purpose, five isonitrogenous (35% protein) and isocaloric (~4,000 kcal/kg) diets have been supplied by supplementing PAE at the varying inclusion levels as 0.0%, 0.25%, 0.5%, 1.0%, and 2.0% diets, and growth performance and feed utilization, digestive enzyme activities, serum biochemical variables, antioxidant responses, and immunological factors were studied. The experiment continued for 60 days. At the termination of the experiment, the mean final weight, weight gain percentage (WG%), feed conversion rate (FCR), and specific growth rate (SGR) have been improved significantly in all fish groups fed PAE-based diets with regard to those fed the reference diets. A second-order polynomial regression equations indicate that the optimum dietary supplementation level of PAE in fish diets was ~1%. Serum cortisol, glucose, triglyceride, cholesterol, and malondialdehyde levels as well as catalase, alanine aminotransferase, and aspartate aminotransferase activities were significantly decreased generally in all PAE-supplemented groups compared to the control groups before and/or after high-temperature stress (32°C). Moreover, serum total protein, albumin, and total immunoglobulin levels as well as ACH50, lysozyme, superoxide dismutase, and glutathione peroxidase activities were increased before and/or after high-temperature stress (32°C). In conclusion, the results showed, for the first time, that dietary supplementation with ~1% PAE can improve growth performance, stimulated the digestive enzymes, and enchanced antioxidant status as well as immune parameters and prevented high-temperature stress of common carp.

In the present study, we conducted a 10-week culture experiment to investigate the effects of taurine on the growth performance, antioxidant properties, and muscle quality of the common carp fed an oxidized lipid diet. There were five experimental groups with three replicates each. Based on the fresh fish oil group (FO), equal amounts of oxidized fish oil (with a thiobarbituric acid-reactive substances value of 49.57 ± 2.34 mg/kg) and 0 g/kg (OFO), 4 g/kg (OT4), 8 g/kg (OT8), and 12 g/kg (OT12) taurine were added to the diet, while the same composition ratio was maintained by changing the microcrystalline cellulose content. Compared to the FO group, the feed conversion ratio, weight gain rate, muscle crude lipid, and n-3/n-6 polyunsaturated fatty acids (PUFA) ratio were significantly lower in the group OFO (P < 0.05). In addition, compared to the FO group, OFO fish showed an increased content of malondialdehyde and protein carbonylation and decreased hardness, brightness, pH, superoxide dismutase, and catalase levels in the muscle (P < 0.05). Notably, the growth index significantly improved in the OT4 group compared to that in the OFO group (P < 0.05). In addition, dietary taurine increased the crude lipid content, n-3/n-6 PUFA, antioxidant capacity, hardness, springiness, brightness, pH, and collagen content in the muscle compared with OFO fish (P < 0.05). Moreover, taurine supplementation significantly reduced myofiber diameter and increased myofiber density (P < 0.05) and enhanced the expression levels of paired box 7 (pax7), myogenic factor 5 (myf5), myogenic differentiation antigen (myod), and myogenic regulatory factor 4 (mrf4) compared with that of the OFO group (P < 0.05). Considering growth performance and muscle quality, the optimal supplemental levels of taurine in the oxidized lipid diet were 4 g/kg and 6.84–7.70 g/kg, respectively.

A 9-week feeding trial was conducted to evaluate the effects of replacing soybean meal (SBM) with sunflower meal (SM) or fermented sunflower meal (FSM) on the growth performance, intestinal microbiota, and intestinal health of genetically improved farmed tilapia (Oreochromis niloticus) (initial weight 6.55 ± 0.01 g). Eleven isonitrogenous and isolipidic experimental diets were formulated by replacing 0%, 20%, 40%, 60%, 80%, and 100% of dietary SBM with SM or FSM. The results showed that the replacement of more than 40% of SBM with SM decreased the weight gain and special growth rate of tilapia, while the complete replacement of SBM with FSM did not affect the growth performance of tilapia. From transmission electron microscopy analyses, it was shown that high levels of both SM and FSM substitution resulted in damage to the intestinal epithelium of tilapia. Replaced of 20% SBM with SM upregulated intestinal tight junction (zo-1, claudin, occludin) and anti-inflammatory (tgf-β1, tgf-β2) gene expression and downregulated pro-inflammatory gene expression (tnf-α, il-1β, il-6, il-8). However, the expression of tight junction, anti-inflammatory, and pro-inflammatory genes showed opposite trends when SBM was substituted by SM at high levels. FSM completely replaces SBM and downregulates the expression of tight junction genes (claudin, occludin), replacement of more than 20% of SBM with FSM downregulated pro-inflammatory (tnf-α, il-1β, il-8) gene expression, whereas substitution of less than 80% increased the expression of anti-inflammatory genes (tgf-β1). The 100% FSM group exhibited a decreased abundance of Fusobacteriota and an increased abundance of Actinobacteriota compared to the control and 100% SM groups. In summary, our data confirm that replacing more than 40% of SBM with SM induces gut inflammation, damages gut health, and decreases growth performance, whereas FSM replacement of SBM did not negatively affect tilapia growth and health, it also did not have a significant ameliorative effect, with some parameters negatively affected at high replacement levels. Therefore, FSM replacement of SBM levels above 80% is not recommended.

This study investigated the effects of substituting fish meal (FM) in practical diet by chlorella meal on the growth, feed utilization, and flesh quality of Pacific white shrimp (Penaeus vannamei). First, a basal diet was prepared with 200 g/kg FM inclusion (FM-20), and then chlorella meal was used to reduce FM inclusion to 150 g/kg (FM-15), 100 g/kg (FM-10), 50 g/kg (FM-5), and 0 g/kg (FM-0), corresponding to the replacement levels of 25%, 50%, 75%, and 100% of dietary FM, respectively. Shrimp (1.37 ± 0.10 g) were fed with the five isonitrogenous and isolipidic diets for 56 days. No significant difference was observed in feed conversion ratio (FCR) and weight gain (WG) between FM-20 and FM-15 group (P > 0.05), but when chlorella meal substituted 50% of dietary FM, WG, protein and lipid retention, and n-3/n-6 PUFAs in flesh were significantly reduced with significant increase in FCR (P < 0.05). Survival, feed intake, meat yield, apparent digestibility coefficient of crude protein, dry matter, and flesh shear force showed no significant difference between FM-20 and substituted groups (P > 0.05). When dietary FM was totally substituted by chlorella meal, the body yellowness and redness and essential amino acid content in flesh, including Lys and Met, were significantly reduced (P < 0.05). No significant differences were found in flesh total collagen, crude lipid, crude protein, serum biochemical indexes, flesh texture profiles (hardness, springiness, etc.), water holding capacity, antioxidant capacity, fatty acid, free amino acid composition, and muscle fiber density among the five treatments (P > 0.05). To sum up, in a practical diet with 200 g/kg FM inclusion, chlorella meal successfully replaced 25% of dietary FM without adverse impacts on the growth and feed utilization, and the substitution of 75% of dietary FM did not negatively affect the flesh quality of Pacific white shrimp.

Erucic acid (EA) in rapeseed oil has adverse effects on terrestrial animal and fish health. However, its antinutritional role in fish remains unclear due to the limited information on EA. Therefore, this study was conducted to assess the impact of EA on growth performance, antioxidative capacity, fatty acid profile, and lipid metabolism in tilapia. Six diets containing different amounts of EA (0, 3, 6, 12, 20, and 27 g/kg diet) were fed to tilapia (initial weight: 3.01 ± 0.01 g) for 8 weeks. The results exhibited that dietary EA did not affect growth performance but remarkedly increased the crude lipid contents (in the whole body, liver, and muscle). It also markedly increased the levels of low-density lipoprotein cholesterol, total cholesterol, nonesterified fatty acids, and triglyceride in the liver and serum in a dose-dependent manner. The EA groups had lower values of total superoxide dismutase, total antioxidant capacity, catalase, and higher activities of aspartate aminotransferase and alanine aminotransferase, as dietary EA levels increased. Feeding fish with diets containing EA (20 and 27 g/kg diet) significantly increased the malondialdehyde content. Moreover, dietary EA greatly altered the fatty acid profile in the liver and muscle. It especially elevated the percentages of C18 : 2n-6, C20 : 1n-9, and C22 : 1n-9 while decreasing the C18 : 0 and C16 : 0 levels. When the levels of EA in diets were 12, 20, and 27 g/kg, genes correlated with lipophagy, lipolysis, and β-oxidation were significantly reduced. Meanwhile, genes concerned in triglyceride synthesis were largely increased in the liver and muscle. In summary, high-dose EA (20 g/kg diet) in the diets significantly induced fat accumulation, hepatic oxidative damage, and abnormal lipid metabolism in tilapia. The current findings expand our understanding on the antinutritional role of EA in lipid homeostasis and fish health.

This study investigated the effects of the dietary replacing fishmeal (FM) with fermented cottonseed meal (FCSM) on growth performance, body coloration, serum biochemistry, muscle quality, and liver antioxidant capacity of juvenile golden pompano (Trachinotus ovatus). Fish were fed with five experimental diets (0 (FM), 12.5% (CSM12.5), 25% (CSM25), 50% (CSM50), and 100% (CSM100) replacement levels) for 8 weeks. The weight gain rate (WGR), specific growth rate (SGR), and condition factor (CF) in fish fed with CSM25 were significantly higher than those of the FM (P < 0.05). ALT, GLU, TG, TC, and LDL of fish fed with CSM100 diet were significantly higher than those in FM (P < 0.05). No significant difference was observed in SOD, CAT, and MDA among all treatments (P > 0.05). The relative gene expression of Nrf2 of fish fed with CSM25 diet was higher than that of the other groups (P < 0.05). The relative gene expression of Keap-1 of fish fed with CSM25 diet was lower than those in FM (P < 0.05). In addition, the replacement of a high proportion of FM with FCSM negatively affect the liver antioxidant capacity of fish. With dietary replacement of FM with FCSM increasing 0%–25%, the relative expressions of GH, myf5, and MSTN were significantly upregulated (P > 0.05). Based on these results, we recommend that of FCSM in the diet of golden pompano, whereas the optimal level of FCSM should be carefully evaluated. In conclusion, the optimum level of dietary replacing FM with FCSM in T. ovatus diet was 24.74%−29.38% based on SGR and WGR.

This study aims to elucidate manipulation impacts of jack mackerel meal (JMM) in the red sea bream (Pagrus major) feeds replacing various animal protein sources for different levels of fish meal (FM) on growth and feed availability. Two-way ANOVA experimental design was applied with three substitution sources: animal protein sources (tuna byproduct meal (TBM), chicken byproduct meal (CBM), and meat meal (MM)) and two FM substitution levels (25% and 50%). The control (Con) diet contained 60% FM. In the Con diet, 25% and 50% of FM were replaced with TBM, CBM, and MM, respectively, and then 24% jack mackerel meal (JMM) was included at the expense of FM, named as the TBM25, TBM50, CBM25, CBM50, MM25, and MM50 diets, respectively. Red sea bream juveniles averaging 11.8 g were distributed in 21 flow-through tanks (20 fish per tank) with triplicate. Fish were carefully hand-fed to apparent satiation for 8 weeks. At the end of the 8-week feeding experiment, the TBM-substituted diets produced significantly (P < 0.0001 for all) greater weight gain, specific growth rate (SGR), and feed consumption of fish than the CBM- and MM-substituted diets. Furthermore, dietary substitution of 25% FM achieved significantly (P < 0.0001, P < 0.0001, and P < 0.0003, respectively) greater weight gain, SGR, and feed consumption than dietary substitution of 50% FM based on two-way ANOVA analysis. Fish fed the TBM50 diet achieved the greatest weight gain, SGR, and feed consumption. Protein retention, biological indices, plasma and serum parameters, and the whole body chemical composition and amino acid (AA) profiles of red sea bream were not significantly influenced by dietary treatments. The TBM-substituted diets achieved significantly (P < 0.0001) greater economic profit index (EPI) than the CBM- and MM-substituted diets. Furthermore, dietary substitution of 25% FM achieved significantly (P < 0.002) greater EPI than dietary substitution of 50% FM. The TBM50 diet produced the greatest EPI. In conclusion, TBM and MM and CBM could replace 50% and 25% FM in the feeds with 24% JMM inclusion, respectively, without compromising the growth, feed utilization, plasma and serum parameters, chemical composition and AA profiles of red sea bream, and EPI. The TBM50 diet was the most desirable treatment in terms of the greatest growth performance of red sea bream and the highest economic return to farmer.