Feed Formulation Research Articles

Modelling the effect of prebiotics, probiotics and other functional additives on the growth, feed intake and feed conversion of European sea bass (Dicentrarchus labrax) juveniles

Dietary supplementation of aquafeeds with functional additives is a commonly employed strategy in order to reduce the potential negative effects associated to fishmeal (FM) and fish oil (FO) replacement by alternative protein and oil sources. Nevertheless, the wide variety of functional ingredients with different bioactive properties hinders the selection of appropriate dietary supplementation strategies on feed formulation. The present study aimed to develop an observational multiple-linear regression (MLR) model to identify the effects of a variety of functional ingredients supplementation on European sea bass juveniles (Dicentrarchus labrax) growth performance and feed utilization. A literature survey was conducted gathering a total of 61 dietary treatments. The functional ingredients were classified in three main groups, namely, “probiotics”, “prebiotics” or “others” (including plant derived compounds such as essential oils, extracts and powders). Three different MLR were obtained and validated, allowing to describe the effects of functional ingredients supplementation on fish specific growth rate (SGR) (with a final R-squared (R2) = 0.96, adjusted R-squared (adj R2) = 0.92 and a p-value= 7.21E-08)), fish feed intake (FI) (R2 = 0.97, adj R2 = 0.95 and a p-value= 5.42E-12)) and fish feed conversion ratio (FCR) (R2 = 0.90, adj R2 = 0.80 and a p-value= 2.02E-05)). MLR model trimming, allowed the detection of a significant positive correlation (cor) between dietary prebiotics supplementation and SGR (cor= 0.32, p-value= 8.52E-04). On the contrary, prebiotic supplementation presented a negative correlation with fish FI (cor= −0.44, p-value= 6.27E-05) and FCR (cor= −0.41, p-value= 8.96E-05).

Feed Regime Slightly Modifies the Bacterial but Not the Fungal Communities in the Intestinal Mucosal Microbiota of Cobia Fish (Rachycentron canadum).

The bacterial community of the intestinal microbiota influences many host functions, and similar effects have been recently reported for the fungal community (mycobiota). Cobia is a tropical fish that has been studied for its potential in marine aquaculture. However, the study of its bacterial community has been underreported and the mycobiota has not been investigated. We analyzed the gut bacterial and fungal profile present in the intestinal mucosa of reared adult cobias fed two diets (frozen fish pieces (FFPs) and formulated feed (FF)) for 4 months by sequencing the 16S rRNA (V3-V4) and internal transcribed spacer-2 (ITS2) regions using Illumina NovaSeq 6000. No significant differences in the alpha diversity of the bacterial community were observed, which was dominated by the phyla Proteobacteria (~96%) and Firmicutes (~1%). Cobia fed FF showed higher abundance of 10 genera, mainly UCG-002 (Family Oscillospiraceae) and Faecalibacterium, compared to cobia fed FFPs, which showed higher abundance of 7 genera, mainly Methylobacterium-Methylorubrum and Cutibacterium. The inferred bacterial functions were related to metabolism, environmental information processing and cellular processes; and no differences were found between diets. In mycobiota, no differences were observed in the diversity and composition of cobia fed the two diets. The mycobiota was dominated by the phyla Ascomycota (~88%) and Basidiomycota (~11%). This is the first study to describe the gut bacterial and fungal communities in cobia reared under captive conditions and fed on different diets and to identify the genus Ascobulus as a new member of the core fish mycobiota.

Nutritional Properties Evaluation of Blowfly Larvae from Fish and Chicken Wastes for Asian Sea Bass Feed Formulation Application

This present research characterized the proximate nutrient, fatty acids and amino acids compositions of the wild third instar blowfly larvae collected from fish and chicken wastes as well as its mixture, in view of aquaculture feeding for Asian sea bass (Lates calcarifer). Analyses of crude protein, crude lipids, crude fiber, ash, carbohydrates, amino as well as fatty acids were performed. Results revealed that the larvae that fed on the mixed substrates (chicken and fish, 50:50 ratio) had significantly the highest nutritional values (51.47 ± 0.32% of crude protein, 29.4 ± 1.47% of crude fat, 4.81 ± 0.83% of crude fiber, 4.85 ± 0.01% of ash and 12.71 ± 1.67% of carbohydrate) for formulating feeds for Asian sea bass when compared with that of chicken and fish wastes alone (P < 0.05). Similarly, significantly higher percentages of fatty acids (DHA and EPA) and amino acids (Arg, Lys, Met, Trp, His, Val, Ile, Leu and Phe) were observed in the larvae from mixed-substrates when compared with that of the remaining two substrates (P < 0.05). The findings supported the utilization of blowfly larvae harvested on mixed substrate as a possible candidate of nutrients for Asian sea bass feed formulations

Magnesium in dairy cattle nutrition: A meta-analysis on magnesium absorption in dairy cattle and assessment of simple solubility tests to predict magnesium availability from supplemental sources

Supplemental Mg sources differ in bioavailability, and solubility is one of the determining factors. We explored whether and which in vitro solubility tests could reliably differentiate the quality of supplemental Mg sources. In experiment 1, we compared 3 chemical methods using an acetic acid solution (50 mL/L, termed vinegar test), a 1 M ammonium nitrate solution, and an artificial rumen buffer fluid without rumen microbiota. The Mg solubility results suggested the vinegar test was the best method due to its robustness, simplicity, and reproducibility. In experiment 2, we validated the reliability of the vinegar test using 4 MgO sources from experiment 1 and 12 new MgO sources plus a laboratory-grade MgO as a standard. Accordingly, we repeated the vinegar test with short (0.5 h) and long (3.0 h) incubation times on these sources and then conducted ruminal incubations in 24-h batch culture experiments. The repeated vinegar test resulted in similar results as in experiment 1. Linear regression across both experiments showed the soluble Mg content (g/kg) = 44.46 (±2.55) × pH - 142.9 (±14.9), root mean square error (RMSE) = 10.2, P slope <0.001, and concordance correlation coefficient (CCC) = 0.953. The predictable pH range was from 4 to 6. The equation cannot be applied to low-alkaline sources such as Mg sulfate, Mg acetate, or a group of MgO with exceptionally high alkaline properties showing a cluster of pH above 8.5. Solubility of the MgO sources in the vinegar test ranged from 5 to 35%, whereas the 24-h ruminal incubations led to more solubility (15-70%). Nevertheless, the differences among most MgO sources were parallel to the data from the in vitro rumen solubility. Next, we performed a meta-analysis of published studies (21 studies, 94 treatments) to assess the true Mg absorption in vivo and potential factors affecting Mg absorption in dairy cows. It appeared that on average dairy cows absorbed about 20% of the Mg intake (range 10-40%), regardless of their lactation status. We revealed a new strategy to predict Mg absorption relative to dietary K as follows: true Mg absorption (g/d) = 0.3395 (±0.025, P < 0.001) × Mg intake (g/d) - 1.9273 (±1.16, P = 0.11) when dietary K ≤20 g/kg DM, and 0.154 (±1.06, P = 0.05) + 0.209 (±0.026, P < 0.001) × Mg intake (g/d) when dietary K >20 g/kg DM (RMSE = 2.19). This strategy improved the accuracy of prediction as compared with the existing prediction (CCC = 0.922 vs. 0.845). Still, over- or underestimations inherent to individual studies were evident and might be related to unaccountable factors, especially the quality of supplemental Mg sources. In conclusion, the vinegar test is a useful tool to rank inorganic Mg sources with alkaline properties. Including in vitro solubility data in Mg nutrition research could help to refine the prediction of bioavailable Mg contents and increase precision in feed formulation.

Aquaculture ecosystem microbiome at the water-fish interface: the case-study of rainbow trout fed with Tenebrio molitor novel diets

BackgroundSustainable aquaculture relies on multiple factors, including water quality, fish diets, and farmed fish. Replacing fishmeal (FM) with alternative protein sources is key for improving sustainability in aquaculture and promoting fish health. Indeed, great research efforts have been made to evaluate novel feed formulations, focusing especially on the effects on the fish gut microbiome. Few studies have explored host-environment interactions. In the present study, we evaluated the influence of novel insect-based (Tenebrio molitor) fish diets on the microbiome at the water-fish interface in an engineered rainbow trout (Oncorhynchus mykiss) farming ecosystem. Using 16S rRNA gene metabarcoding, we comprehensively analyzed the microbiomes of water, tank biofilm, fish intestinal mucus, fish cutis, and feed samples.ResultsCore microbiome analysis revealed the presence of a highly reduced core shared by all sample sources, constituted by Aeromonas spp., in both the control and novel feed test groups. Network analysis showed that samples were clustered based on the sample source, with no significant differences related to the feed formulation tested. Thus, the different diets did not seem to affect the environment (water and tank biofilm) and fish (cutis and intestinal mucus) microbiomes. To disentangle the contribution of feed at a finer scale, we performed a differential abundance analysis and observed differential enrichment/impoverishment in specific taxa, comparing the samples belonging to the control diet group and the insect-based diet group.ConclusionsOmic exploration of the water-fish interface exposes patterns that are otherwise undetected. These data demonstrate a link between the environment and fish and show that subtle but significant differences are caused by feed composition. Thus, the research presented here is a step towards positively influencing the aquaculture environment and its microbiome.

Characterization of By-products with High Fat Content Derived from the Production of Bovine Gelatin.

Background:Gelatin is a protein obtained by partial hydrolysis of collagen contained in skins, connective tissue and/or animal bones, which are by-products of the meat industry. The main raw material to produce bovine gelatin is the dermis of the skin, but there is a variation in fat and moisture content depending on the bovine skin origin. As a contribution to the circular economy and sustainability, these by-products with high fat content and the fat released from them during the gelatin production process can be managed for food industries, mainly in the development or formulation of animal feed. Methods:For the initial physicochemical characterization, moisture, fat, protein and ashes content were determined. Once the by-products with high fat content were identified, alteration parameters such as acidity, peroxide and saponification indexes were evaluated. Additionally, thermal, rheological and fatty acid composition characterization was carried out in order to study the possible applications of the by-products. Results and Discussion:The results showed that certain by-products have a fat content of less than 15%, so the viability of their use is limited. On the other hand, some by-products have a fat content exceeding 30%; however, their extraction can only be done manually, resulting in a low efficiency process. By-products removed from the supernatant in the extractors presented fat percentages of 99.9 and 98.9%, and there exists the possibility of implementing a mechanical method for their extraction. The analysis of alteration and oxidation parameters, thermal and rheological characterization, fatty acid profile and solid fat content were exclusively conducted on these high-fat content by-products. Based on the characterization, these by-products could be valued and incorporated into animal feed formulations. Nevertheless, certain limitations exist for their use in applications such as biodiesel production or the food industry.

A comparison of digestive strategies for fishes with different feeding habits: Digestive enzyme activities, intestinal morphology, and gut microbiota.

Fish feeding habit determines the digestive tract structure and intestinal microflora. However, the relationship between feeding habit, digestive intestinal morphology, and microbial diversity of omnivorous, herbivorous, plankton feeder, and carnivorous fish from the same environment has not been compared. This study compared the digestive enzyme activities, intestinal morphology, and intestinal microflora of omnivorous (Carassius auratus), herbivorous (Ctenopharyngodon idellus), carnivorous (Siniperca chuatsi), and plankton feeder (Schizothorax grahami) fishes and predicted the potential functions of specific microflora on different nutrients. Twelve intestine samples were collected from each of the four fishes from Dianchi Lake. The composition and diversity of microbial communities were determined by using high-throughput sequencing of 16S rDNA. The results showed that the carnivorous fish (S. chuatsi) had higher trypsin and pancrelipase activities in the hepatopancreas and enteropeptidase in the intestine, but lower amylase activities in the intestine. The carnivorous fish intestine had more microvilli branches and complex structures than other fish species in the order carnivorous > herbivorous > plankton feeder > omnivorous. The intestinal microflora diversity was higher in the omnivorous fish and followed the order omnivorous > herbivorous > plankton feeder > carnivorous. Acinetobacter species and Bacteroides species were the most dominant flora in the carnivorous and herbivorous fishes, respectively. Acinetobacter species and Pseudomonas species might help the host to digest protein, while Bacteroidetes species may help the host to digest cellulose. Taken together, feeding habit determines the digestive enzyme activities, intestinal tissue morphology, and differential colonization of fish intestinal flora. The knowledge obtained is useful in feed formulation and feeding practices for the studied fish species.

Application of a stoichiometric bioenergetic approach and whole-body protein synthesis to the nutritional assessment of juvenile Thenus australiensis

The present study successfully combined a stoichiometric bioenergetic approach with an endpoint stochastic model to simultaneously determine specific dynamic action, metabolic substrate use and whole-body protein synthesis in juvenile slipper lobster Thenus australiensis. Juvenile lobsters were fasted for 48 h to investigate routine metabolism before receiving a single meal of formulated feed containing 1% 15N-labeled Spirulina. Postprandial oxygen consumption rate, dissolved inorganic carbon, and total nitrogen excretion returned to the pre-feeding level within 24 h. The rate of whole-body protein synthesis was 0.76 ± 0.15 mg CP g−1 day−1, with a significant reduction from 24 to 48 h post-feeding. The postprandial increase in whole-body protein synthesis accounted for 13–19% of total oxygen uptake. Protein was the primary energy substrate for 48 h fasted (45% oxygen consumption) and post-feeding lobster (44%), suggesting that dietary protein was not efficiently used for growth. The secondary energy substrate differed between carbohydrates in 48 h fasted and lipids in post-feeding lobsters. The present study recommends integrating protein synthesis into protein requirement experiments of marine ectotherms to acquire a more comprehensive picture of protein and energy metabolism and nutritional physiology crucial for formulating cost-effective aquafeeds.

Investigating the Genetic and Dietary Factors Influencing Foot Muscle Color and Growth in Haliotis gigantea

Haliotis gigantea, a commercially cultivated abalone in China, predominantly displays the pale-yellow-footed trait. However, a limited occurrence of the orange-footed muscle trait makes it a valuable candidate for breeding programs. In our research, we examined the inheritance pattern of the orange-footed trait and conducted a 90-day feeding trial for H. gigantea to compare the influence of formulated feed and macroalgae on pigment enrichment and growth rates. Our results suggest that the orange-footed trait has a recessive nature relative to its common counterpart and demonstrates stable inheritance. We also identified a significant correlation between color-difference values (a*) and total carotenoid content (TCC) (R2 = 0.955, p &lt; 0.05), suggesting the TCC in abalone foot muscle can be estimated using the a* value. Furthermore, introducing carotenoids to formulated feed imparts an orange hue to the foot muscle, but this effect is inferior compared to using Gracilariopsis lemaneiformis with a similar carotenoid content. This suggests that H. gigantea has a higher absorption efficiency for the carotenoids from the macroalgae G. lemaneiformis compared to formulated feed. Growth assessments indicate that the formulated feed, enriched with higher crude protein than G. lemaneiformis, optimally supports H. gigantea growth. Our findings furnish valuable insights that could steer breeding strategies and feeding practices towards achieving the orange-footed muscle trait in H. gigantea.

Comparative study on the valorization of Sargassum from the Mexican Caribbean coast and Gulf of California as an ingredient on healthy diets for shrimp farming

Sargassum biomass is a potential ingredient for aquaculture formulations due to its high nutritional value and availability, as it contains a variety of essential nutrients including proteins, carbohydrates, lipids, vitamins, antioxidants, fiber, and minerals, which are essential for aquatic growing, development and health parameters including digestibility and immune response against diseases. Therefore, in this work, five experimental diets were formulated considering 2.5 % and 5 % levels of inclusion of Sargassum spp. from the Mexican Caribbean coasts (SC), and from the Gulf of California (SG), and one reference diet as a control. The characterization of the raw material and the proximal analysis of the five diets were evaluated according to standard reference methods. A 35-day feeding trial was conducted using juvenile Litopenaeus vannamei showed a shrimp survival rate of 97 ± 6 % (p > 0.05) on SC. Excellent weight gain (WG) performance of SC and SG diets at 2.5 % of inclusion resulted in >10 % WG compared to the control. The specific activity of amylase, lipase, trypsin, and chymotrypsin showed a significant increase by including Sargassum in diets, compared with the reference diet. Incorporating Sargassum at 2.5 % in feed formulations for shrimps showed a great opportunity to use it as an ingredient and improved production yields. The digestion and absorption parameters were represented by the enzymatic activity in which the diets based on Sargassum spp. from the Mexican Caribbean coast (SC) have resulted in the best performance.

Growth Performance and Nutrient Utilization of Clarias. gariepinus Fed Soaked Boscia senegalensis Supplemented Diets

The present study investigated the nutritional suitability and cost effectiveness of a Sahelian plant seeds, Aizien (Boscia senegalensis) as alternative to Soy bean meal in the diet of African Catfish (Clarias gariepinus Burchell, 1822). Raw seeds of the B. senegalensis were subjected to processing method intended to reduce levels of the most important antinutritional factors (ANFs). The resultant product was used to formulate five isonitrogenous (40%) diets, containing the seed meals at inclusion levels of 25% to 100% of dietary protein and fed to Fingerlings of the African Catfish at 5% of their body weight for a period of 24 weeks. The feeding trial involved one hundred and fifty (150) fingerlings of C. gariepinus(2.43g –3.10g) randomly stocked at ten fish per Tank (200L) in a non-flow through design with regular water replacement and water quality monitoring. Important growth performance and nutrient utilization indices, weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and Feed conversion efficiency (FCE) of fish in the experimental groups fed SBS based showed that Fish fed 50% SBS diet recorded the highest WG (439.14g), SGR (1.34%/day) and FCR (1.35). This could be attributed to the protein quality of the diets in relation to the dietary essential amino acid profile of the experimental diets used. Generally, the Fish fed the 100%SBS diet recorded the lowest growthperformance with regards to WG (360.68g), SGR(1.25), FCR (1.61), PER (1.58) and FCE (62.22%).From the results of this experiment, for better production of African catfish C. gariepinus, replacement levels of 50 SBS may serve as good alternative to SBM in feed formulation for C. gariepinus.

Weight–Length Relationship and Condition Factor of Gibel Carp (Carassius auratus gibelio var. CAS V) at Different Growth Stages and Feed Formulations

Accurate recording of growth indicators for aquaculture species at different stages is essential for evaluating aquaculture production effectiveness and the rationality of feed formulations. Due to their convenience and non-invasiveness, weight, length, and condition factor are commonly used to assess the growth of aquaculture species. However, fish growth indicators, can vary significantly with age structure and feed components (nutrition), and relying on a single indicator may lead to misjudgments. In this study, we investigated the growth indicators of Gibel carp (Carassius auratus gibelio var. CAS V) at different growth stages (juvenile and adult) and different feed formulations. Meanwhile, the fish weight–length relationship (W=bLa) was used to assess the growth indicators. The results showed that the weight–length relationship of Gibel carp varied significantly with age and feed formulation. Additionally, the condition factor calculated depended on the weight–length relationship being more similar with weight and length change trend than the condition factor was measured. Weight analysis indicated that weight, length, depth, body width, and carcass ratio had higher weights when analyzing fish growth. Therefore, during aquaculture production, fish growth evaluating requires considering diverse indicators such as weight, length, body depth, body width, and carcass ratio, as well as the condition factor, to avoid misjudging the actual growth situation. Meanwhile, the use of the condition factor should consider the sufficient number of data and whether the assumptions (such as being in an isometric growth period) are met.

Dietary methylmercury and fatty acids affect the lipid metabolism of adipose tissue and liver in rainbow trout

Methylmercury (MeHg) is a pervasive environmental contaminant in aquatic ecosystems that can reach elevated concentrations in fish of high trophic levels, such as salmonids. The present study aims at investigating the individual and combined impacts of dietary MeHg and fatty acids on lipid metabolism in juvenile rainbow trout (Oncorhynchus mykiss) with a focus on two key organs, adipose tissue and liver. MeHg and fatty acids are both known to act on energy homeostasis although little is known about their interplay on lipid metabolism in fish. Fish were fed diets enriched in linoleic acid (LA, 18:2 n-6), α-linolenic acid (ALA, 18:3 n-3), eicosapentaenoic acid (EPA, 20:5 n-3) or docosahexaenoic acid (DHA, 22:6 n-3) for ten weeks, with the addition of MeHg to the diets during the last six weeks (0, 2.4 or 5.5 mg MeHg/kg dry matter). LA and ALA are polyunsaturated fatty acids (PUFA) typical of plant-derived oils whereas EPA and DHA are n-3 long chain PUFA largely found in fish oil, all used in feed formulation in aquaculture. The results showed that the LA-enriched diet induced a higher whole-body lipid content compared to the three other diets. On the contrary, the addition of MeHg led to a significant reduction of the whole-body lipid content, regardless of the diet. Interestingly, the adipocytes were larger both in presence of LA, compared to EPA and DHA, or MeHg, indicating a lipogenic effect of these two compounds. No effect was, however, observed on lipid accumulation per gram of adipose tissue. The fatty acid composition of adipose tissue and liver was significantly modified by the dietary lipids, reflecting both the fatty acid composition of the diets and the high bioconversion capacity of the rainbow trout. Exposure to MeHg selectively led to a release of n-6 PUFA from the hepatic membranes of fish fed the LA-enriched diet, showing a disruption of the pathways using n-6 PUFA. This study highlights the significant impact of MeHg exposure and dietary fatty acids on lipid metabolism in fish. Further investigation is needed to elucidate the underlying mechanisms and to explore the potential involvement of other organs.

Utilization of Kelakai Wetland Plants (Stennochlaena palutris) and Different Doses of Probiotics in Feed Formulations on the Growth of Climbing Perch (Anabas testudineus Bloch)

The aim of the study was to test the provision of feed made from kelakai with the best probiotic dose for the growth of climbing perch. It is expected that the feed formulation made from kelakai in the form of pellets will increase its growth by administering probiotics. The research method used a completely randomized design (CRD) with 4 treatments and 3 replications, rearing for 30 days in an aquarium. Treatment A: feeding pellets with 20% kelakai flour and 0% probiotics, treatment B: feeding pellets with 20% kelakai flour and 5% probiotics treatment C: feeding pellets with 20% kelakai flour and 10% probiotics, treatment D: giving pelleted feed with 20% kelakai flour and 15% probiotics. The results showed that all treatments were not significantly different, the highest relative length growth was in treatment C (20% kelakai flour; 10% probiotics), the highest relative weight growth of climbing perch was in D treatment (20% kelakai; 15% probiotics), survival 100 % in all treatments. Water quality is within a range that supports the growth and survival of climbing perch.

Design, Fabrication and Performance Evaluation of a Poultry Feed Pelleting Machine

The poultry industry plays a crucial role in meeting the global demand for animal protein. To ensure optimal growth and productivity of poultry, the formulation and processing of high-quality feed are essential. Feed pelleting is a common method employed to enhance the nutritional value, digestibility, and handling characteristics of poultry feed. The machine which meant for the production of poultry feed pellets in good quantities, was designed, fabricated and its performance evaluation was carried out accordingly. The independent dual operated Poultry Feed Pelleting Machine permits constant production line since the prime mover (diesel engine) would be plunged into operation as at when due, that is, when electricity power supply failed. The materials used were locally sourced which included; mild steel, high carbon steel, aluminum, 3hp electric motor, prime mover and axle. The base materials are corn, soybean, wheat, rice bran, wheat bran, herbs, fish meal, groundnut cake etc. The machine functioned reliably at the throughput capacity of 95kg per hour and up to 800kg per day with 95% efficiency proved its high performing rate. Moreover, the study showed that useful information in designing pelleting machine that produced pellet optimally when the appropriate moisture condition for feed materials is considered ranging from 20% - 30% with temperature range of 500C-700C. The results indicate that the developed machine offers significant advantages in terms of pellet quality, production efficiency, and energy consumption compared to conventional pelleting methods. The developed machine is recommended to facilitate the production of poultry feed pellets for small scale and medium scale farmers.

Nutritional Composition of House Cricket (Acheta domesticus) and Dung Beetle Larva (Oryctes boas) in Osun State: Implication to Dietary Improvement in Nigeria

Background: Edible insects and the act of eating insects (Entomophagy) are common across the globe. Feeding variations and species differences, among other factors, influence these individuals’ chemical and mineral components. The current study elucidated the nutritional composition of house cricket (Acheta do-mesticus) and dung beetle larva (Oryctes boas) collected in Osun State, Southwestern Nigeria. Methods: The nutritional composition of the two species of insects sampled randomly was determined following standard methods of the Association of Official Analytical Chemists. The ground crickets and beetle larvae were digested with HNO3 and HCl in a microwave digestion system; inductively coupled plasma-optical emission was used to determine the amounts of Calcium, Sodium, Potassium, Phosphorus, Magnesium, Iron, Copper, Manganese, and Zinc in the samples. Following a standard procedure, the amino acid profile was performed using a Biochrom30+ amino acid analyzer (Pharmacia-Biotech, Buckinghamshire, UK). Data obtained were expressed as means ± standard deviations of triplicate analyses and compared among the two insect species using Student’s t-test at p &lt; 0.05. Results: Generally, the nutritional components of A. domesticus were higher than that of O. boas. The O. boas was not significantly higher (P&gt; 0.05) in Iron (6. 83 ± 1. 80 mg/100 g dry matter) but significantly high-er (P&lt; 0.05) in Magnesium (730. 94 ± 2. 64 mg/100 g dry matter) than A. domesticus. All Essential Amino Acids (EAAs) and Non-Essential Amino Acids (NEAAs) were present in the two insect species with varying concentrations. House cricket, however, has a significantly higher (P&lt; 0.05) Arginine, Valine, Phenylalanine, Glutamine, and Glutamic Acid than O. boas. Conclusion: The two insects under this study are edible and of great nutritional values. The results of the nutritional composition of Acheta domesticus and Oryctes boas may serve as the basis for improvement in human food and feed formulation in Nigeria

The use of maggot (Hermetia illlucens) oil in artificial feeds on the growth performance and survival rate of saline tilapia (Oreochromis niloticus)

Tilapia is one of the commodities favored by the community and is widely cultivated in Indonesia. At this time, the development of tilapia cultivation has entered the location of marine and brackish waters, known as saline tilapia. The increase in tilapia cultivation has increased feed production, so the price of raw materials, especially fish oil, has increased. The source of crude fat that is usually used in feed formulations is fish oil, but the availability of fish oil is limited, so the price is increasing. One of the alternatives that can replace fish oil is maggot oil. Maggot contains 42-48% lipids. The purpose of this study is to find the effect of giving maggot oil on the growth and survival of saline tilapia. The method used was experimental, with a completely randomized design (CRD) consisting of 4 treatments and three replications. The treatments tested were treatment A (control), B (1.5 ml of maggot oil), C (2 ml of maggot oil), D (2.5 ml of maggot oil)) on 100 grams of feed. The saline tilapia used was 1.4-1.9 grams/head. The fish were reared for 30 days in 15-liter volume containers, ten fish density, and were fed three times a day. The results showed that fish oil substitution using maggot oil (H. illucens) significantly affected FUE, SGR, absolute weight, FCR, and SR of saline tilapia. The best dose of maggot oil was found in treatment B with a dose of 1.5 ml/100 grams of feed capable of producing FUE (88.78±3.80%), SGR (7.98±0.23%/day), absolute weight (41 .17± 4.57gram), FCR (1.13±0.05), and SR (100±0.00%).Keywords:BSFBrackish waterSGRProductionWeight

Effect of different inclusion levels of defatted Hermetia illucens larvae meal on fillet quality of gilthead sea bream (Sparus aurata)

Abstract In recent years, insect meal has attracted increasing interest as an innovative protein source to replace fish meal in feed formulation due to its valuable nutritional profile. This research aimed to compare the effects of different dietary inclusion levels (5, 10, and 15%) of Hermetia illucens (HI) larvae meal on Sparus aurata (initial weight: 98.6 ± 0.6 g) sensorial, technological, and nutritional fillets quality. Fish were fed experimental diets over 113 days. Results showed that the inclusion of defatted HI larvae meal did not induce off-flavours in gilthead sea bream fillets. No significant differences were found in appearance, mouthfeels, and texture, while a difference emerged in the trait ‘cooked chicken breast’ for odour and flavour characteristics. Moreover, fillets’ quality traits and proximate composition analyses performed did not show significant differences between the treatments. The fillets’ fatty acid content showed that higher inclusion of HI meal leads to higher saturated fatty acids content, while no significant difference in polyunsaturated fatty acids was observed among treatments. Results have a positive implication as dietary HI did not negatively affect the fatty acids composition or quality of sea bream fillets.

Oleic acid as potential immunostimulant in metabolism pathways of hybrid grouper fingerlings (Epinephelus fuscoguttatus × Epinephelus lanceolatus) infected with Vibrio vulnificus

Grouper culture has been expanding in Malaysia due to the huge demand locally and globally. However, due to infectious diseases such as vibriosis, the fish mortality rate increased, which has affected the production of grouper. Therefore, this study focuses on the metabolic profiling of surviving infected grouper fed with different formulations of fatty acid diets that acted as immunostimulants for the fish to achieve desirable growth and health performance. After a six-week feeding trial and one-week post-bacterial challenge, the surviving infected grouper was sampled for GC–MS analysis. For metabolite extraction, a methanol/chloroform/water (2:2:1.8) extraction method was applied to the immune organs (spleen and liver) of surviving infected grouper. The distribution patterns of metabolites between experimental groups were then analyzed using a metabolomics platform. A total of 50 and 81 metabolites were putatively identified from the spleen and liver samples, respectively. Our further analysis identified glycine, serine, and threonine metabolism, and alanine, aspartate and glutamate metabolism had the most impacted pathways, respectively, in spleen and liver samples from surviving infected grouper. The metabolites that were highly abundant in the spleen found in these pathways were glycine (20.9%), l-threonine (1.0%) and l-serine (0.8%). Meanwhile, in the liver l-glutamine (1.8%) and aspartic acid (0.6%) were found to be highly abundant. Interestingly, among the fish diet groups, grouper fed with oleic acid diet produced more metabolites with a higher percent area compared to the control diets. The results obtained from this study elucidate the use of oleic acid as an immunostimulant in fish feed formulation affects more various immune-related metabolites than other formulated feed diets for vibriosis infected grouper.

Reassessment of dietary protein and lipid requirements for large yellow croaker, Larimichthys crocea, reared in net pens

AbstractAt present, large yellow croaker, Larimichthys crocea, a carnivorous fish ranked fifth in aquaculture production among marine finfishes in the world, still relies on raw fish diet because formulated feed alone is not able to sustain rapid growth of the fish. The present study evaluated growth, feed utilization efficiency, body composition and antioxidant capacity of large yellow croaker fed diets containing four protein (430, 460, 490 and 520 g/kg) and three lipid (60, 90 and 120 g/kg) levels. Fish weighing 11.4 ± 2.8 g were fed with the test diets in net pens for 8 weeks. Final body weight and nitrogen retention efficiency (NRE) were dependent on dietary protein and lipid levels and their interaction. Weight gain, body protein content, serum catalase (CAT) activity and liver glutathione peroxidase (GSH‐Px) activity were dependent on dietary protein and lipid levels. Phosphorus retention efficiency was dependent on dietary protein level and interaction between protein and lipid levels. Hepatosomatic index, body lipid and energy contents, activities of superoxide dismutase (SOD) and GSH‐Px in serum, and CAT activity and malondialdehyde content in liver were dependent on dietary lipid level. The final body weight and weight gain of fish fed at 490 g/kg protein level did not significantly differ from those fed at 520 g/kg protein level. The final body weight, weight gain and NRE of fish fed at 90 g/kg lipid level were higher than those fed at 60 g/kg lipid level, but did not significantly differ from those fed at 120 g/kg lipid level. The maximum weight gain occurred in fish fed the diets either containing 520 g/kg protein or 90 g/kg lipid. The body lipid content, as well as SOD and GSH‐Px activities in serum, were higher in fish fed the diets with 90 and 120 g/kg lipid compared to fish fed the diets with 60 g/kg lipid. The present study reveals that the optimal dietary protein and lipid levels for large yellow croaker reared in net pens were 490–520 g/kg and 90 g/kg, respectively.