Levels Of Fish Meal Research Articles

The digestive enzyme activity, intestinal microbiota and immune-related genes expression of snakehead fish (Channa argus) juveniles affected by dietary cricket (Gryllus testaceus) meal

This study aimed to investigate the potential of using cricket (Gryllus testaceus) meal as the main protein source in fish feed for snakehead fish (Channa argus) juveniles. A 10-week feeding trial was conducted to assess the effects of partial replacement of fishmeal (FM) with cricket meal (CM) on growth performance, digestive enzyme activity, intestinal microbial composition, liver antioxidant capacity, immune response and determine the appropriate replacement FM level with CM in juvenile Channa argus diet. Five isonitrogenous and iso-lipid experimental diets were formulated by replacing 0 %, 15 %, 30 %, 45 % and 60 % of FM with CM, respectively named T0 (control group), T15, T30, T45 and T60 groups. The results demonstrated T45 and T60 showed a significantly decreased feed conversion ratio (FCR) than T0 (P < 0.05). Crude lipid content was significantly higher in T45 and T60 than in T0 (P < 0.05). With increasing dietary CM content, the activities of amylase and lipase were significantly increased in T60 (P < 0.05). At the phylum level, 16S rDNA sequences revealed that Proteobacteria abundance was dominant in all treatments, while Ralstonia abundance had higher significance in T60 than others at the genus level (P < 0.05). The total antioxidant capacity (T-AOC) in liver in T30 and T45 were significantly higher than in T0 (P < 0.05). Glutathione peroxidase (GPx) activities had a significant increase in fish fed groups except T0 (P < 0.05), while malondialdehyde (MDA) content was significantly lower within T45 and T60 than T0 (P < 0.05). The up-regulated gene expression level (IL-1β, IL-10, and HSP70) and down-regulated expression level (IL-8) were showed in all treatments with CM replacement. HSP90 and Iκ-Bα expression levels were increased and peaked in T30 (P < 0.05). According to the results of the current study, in Channa argus diets, FM replacement with CM can be up to 30 % without compromising growth performance, enzyme activities, antioxidant capacity, intestinal microbiota, and immune response.

Stress response of European seabass (Dicentrarchus labrax) fed plant-based diets supplemented with swine blood hydrolysates

To improve fish welfare, it is essential that aquafeeds are designed to help fish cope with the stressful conditions of fish farms. One effective strategy to achieve this goal is to supplement the diet with bioactive hydrolysates. Here, diet supplementation to modulate oxidative stress after air exposure was investigated in European seabass, using swine blood hydrolysates (BH), obtained either by autohydrolysis (AH) or enzymatically. The enzymatically produced BH were further submitted to a micro- (RMF) and nanofiltration (RNF). Four isolipidic, isoproteic and isoenergetic diets were developed: a plant-based diet with low (12.5%) fishmeal levels (control, CTRL) and three diets where 3% of each BH (RMF, RNF and AH) was added to the CTRL. Diets were assigned to triplicate groups of 71 European seabass juveniles (initial weight 12.3 ± 1.4 g). After 12 weeks, 9 fish per treatment were either immediately sampled or air-exposed for 1 min and let to recover in a new system for 6 h prior to sampling. Stress response increased cortisol levels, followed by an increment in plasma lactate. The challenge increased liver lipid peroxidation (LPO) due to reactive oxygen species (ROS) accumulation. Carbonyls decreased post-stress, maybe due to a possible interaction with the LPO radicals, reducing protein oxidation. None of the BH improved plasma stress response. By reducing catalase levels without increasing LPO, the RNF treatment appears to adjust European seabass' antioxidant defences, indicating its potential to supply exogenous antioxidants to combat oxidative stress induced by ROS. However, this impact was not sufficient to lower LPO levels compared to a control plant-based diet. The tested diets seemed to affect the fish oxidative stress response in the liver, possibly due to the presence of bioactive peptides, which aided in the non-enzymatic modulation of stress response, as observed by the total antioxidant capacity values in the liver.

Yeast-extracted nucleotides and nucleic acids as promising feed additives for European sea bass (Dicentrarchus labrax) juveniles

Nowadays functional ingredients have a significant potential for improving current low fish meal (FM) aquafeed formulation in sustaining growth and enhancing animal robustness for Mediterranean aquaculture. Among them, nucleotides (NT) and nucleic acids (NA) drew attention for their application in the last two decades. NT are organic molecules involved in many life-supporting pathways, and are the building blocks of NA, which stand as genetic repositories. NT are naturally present in organic ingredients, and among them FM is known to be one of the highest NT sources. When this NT source is seriously limited, fish might be under the minimum NT requirements, especially in fast growing life stages of carnivorous species. Hence, a trial on European sea bass juveniles was carried out, testing two dietary FM levels (FM10, FM20 as 10% and 20% FM, respectively) supplemented with 500 mg kg-1 yeast-originate NT or NA dose over 80 days. Thereafter, fish were exposed to one week of sub-optimal thermal and dissolved oxygen condition (30°C and 4.0 mg/L O2) to further explore the effect of NT and NA inclusion on immune response and gut microbiome alteration. At the end of the growth period NT increased feed intake at both FM dietary levels. FM20 combined with NA and NT further improved growth performance, enhancing lipid efficiency and increased anti-inflammatory TGF-β. After sub-optimal environmental conditions both NT and NA exerted prebiotic functions on gut microbiome by promoting beneficial lactic acid bacteria such as Weissella and Leuconostoc. At the same time NT in 10% FM diet increased the abundance of Bacillus taxon. In conclusion, the combination of NT/NA included at 500 mg kg-1 was able to promote growth when included in 20% FM level, assuming higher nutritional NT requirement when combined with 10% FM. On the other hand, NT/NA added in 10% FM upregulate proinflammatory IL-1β and favor beneficial gut bacterial taxa.

Effects of Hermetia illucens larvae meal on the Pacific white shrimp (Litopenaeus vannamei) revealed by innate immunity and 16S rRNA gene sequencing analysis

The larvae of the black soldier fly, Hermetia illucens, are now attracting attention and becoming promising sources for aquafeed ingredient due to the nutritious substance. However, the introduction of a novel ingredient into the recipe may have unpredictable effects on the innate immune function and gut bacteria composition of crustaceans. Therefore, the present study aimed to evaluate how dietary black soldier fly larvae meal (BSFLM) affected the antioxidant ability, innate immunity and gut microbiome of shrimp (Litopenaeus vannamei) fed with a practical diet, including the gene expression of Toll and immunodeficiency (IMD) pathways. Six experimental diets were formulated by replacing gradient levels of fish meal (0 %, 10 %, 20 %, 30 %, 40 % and 50 %) based on a commercial shrimp diet. Four replicates of shrimp were fed different diets three times daily for 60 days. Growth performance linearly decreased with increasing BSFLM inclusion. Results of antioxidative enzyme activities and gene expression suggested that low dietary BSFLM levels activated the antioxidant capacity of shrimp, while dietary BSFLM levels up to 100 g/kg may induce oxidative stress and inhibit glutathione peroxidase activity. Although traf6, toll1, dorsal and relish were significantly upregulated in different BSFLM groups, the expression of tak1 was significantly downregulated in groups containing BSFLM, implying the immune susceptibility may be weakened. Gut flora analysis indicated dietary BSFLM altered both beneficial and opportunistic pathogenic bacterial abundance, with low levels of dietary BSFLM increased the abundance of bacteria that may contribute to carbohydrate utilization, while high levels of dietary BSFLM may cause intestinal disease and low intestinal immune response. To conclude, 60–80 g/kg of dietary BSFLM showed no adverse effects on the growth, antioxidant capacity and gut flora of shrimp, which was the adequate level in shrimp diet. While 100 g/kg dietary BSFLM may induce oxidative stress and potentially weaken the innate immunity of shrimp.

Effects of Yellow Mealworm (Tenebrio molitor) on Growth Performance, Hepatic Health and Digestibility in Juvenile Largemouth Bass (Micropterus salmoides).

This study investigated the effects of yellow mealworm meal (TM) on growth performance, hepatic health and digestibility in juvenile largemouth bass (Micropterus salmoides). The fish were fed with the basic feed and the test feed (70% basic feed and 30% raw materials) containing Cr2O3, and feces were collected for digestibility determination. The fish were fed with five isonitrogenous (47% crude protein) and isolipidic (13% crude lipid) diets, in which fishmeal (FM) was replaced with 0% (TM0), 12% (TM12), 24% (TM24), 36% (TM36) and 48% (TM48) TM. The fish were reared in cylindrical plastic tanks in a recirculating aquaculture system for 11 weeks. The apparent digestibility coefficients (ADC), of dry matter, crude protein and crude lipid, in largemouth bass of TM were 74.66%, 91.03% and 90.91%, respectively. The ADC of total amino acid (TAA) of TM in largemouth bass was 92.89%, and the ADC of essential amino acid (EAA) in TM in largemouth bass was 93.86%. The final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) in the TM24 group were significantly higher than those in other groups. Similarly, the highest mRNA expression levels of hepatic protein metabolism genes (pi3k, mtor, 4ebp2 and got) and antioxidant enzyme (glutathione peroxidase, Gpx; catalase, Cat) activities were observed in the TM24 group. Moreover, the expression levels of anti-inflammatory factors (il-10 and tgf) in liver were up-regulated and the expression levels of pro-inflammatory factors (il-8 and il-1β) in liver were down-regulated. Quadratic regression model analysis, based on weight gain rate (WGR) against dietary TM level, indicated that the optimum level of dietary TM replacing FM in largemouth bass diet was 19.52%. Appropriate replacement levels (less than 36%) of FM by TM in the diets can enhance the antioxidant capacity and immunity of largemouth bass. However, high levels of FM substitution with TM (more than 48%) in the feeds can damage the liver health and inhibit the growth of largemouth bass. Notably, largemouth bass has high ADC and high utilization of TM, which indicates that it is feasible to use TM as feed protein source for largemouth bass.

Impact of temperature and dietary replacement of fishmeal on cardiovascular remodelling and growth performance of adult Atlantic salmon (Salmo salar L.)

The development of pathophysiological cardiac alterations in farmed salmonids is a recurrent and widespread welfare issue. Although the aetiology of such cardiac alterations is still unclear, several factors, including rearing temperature, selective breeding programs, and feeding strategies, could induce a morpho-physiological remodelling of cardiac structure. This maladaptive cardiac remodelling could impair cardiac function and health of farmed salmonids leading to premature mortality and production losses. In this study, we aimed to better understand the impact of suboptimal elevated temperature, resembling a typical summer temperature in Tasmania, and different feed formulations with low inclusion of fishmeal on cardiovascular remodelling and growth performance of adult Tasmanian Atlantic salmon. Fish were reared in a seawater recirculating aquaculture system and fed one of three diets with different fishmeal contents (6, 12, and 18%), while exposed to a temperature profile characterised by an incremental increase (1 °C per day) from 15 to 19.5 °C, 84 days at 19.5 °C (elevated temperature), and finally 34 days at 15 °C (optimal temperature). In terms of cardiac morphometric parameters, ventricular roundness (measured as height:width ratio) was not affected by temperature or dietary treatment. Conversely, the angle between the bulbus arteriosus and the ventricle significantly increased after the elevated temperature phase, along with relative ventricular mass, showing signs of maladaptive remodelling compared to initial conditions. However, these cardiac parameters were not different between the elevated and optimal temperature phase, which was associated with no changes in transcript abundance of molecular markers of pathological hypertrophy and remodelling, such as, atrial natriuretic peptide (anp) and b-type natriuretic peptide (bnp). Collectively, standard growth rate (SGR) and temperature growth coefficient (TGC), along with feed conversion ratio (FCR), were significantly elevated following exposure to suboptimum elevated temperature relative to optimal temperature. However, no differences in growth rate were observed in fish fed distinct dietary treatments at both elevated and optimal temperatures. These results imply that feeds with low levels of fishmeal can be used under challenging Tasmanian summer conditions without detrimental effect on salmon growth performance. Furthermore, our findings suggest that suboptimal elevated temperatures may induce remodelling of cardiac structure in adult Atlantic salmon, thereby potentially compromising cardiac function and overall health. Future efforts to manage Atlantic salmon susceptibility to climate change will require further research on the effect of challenging environmental conditions on cardiac physiology and performance in an attempt to prevent cardiac pathology, thereby improving health and welfare of farmed salmonids.

Fish Meal Replacement and Early Mild Stress Improve Stress Responsiveness and Survival of Fish after Acute Stress.

Stress responsiveness and fish meal (FM) replacement are two of the most important concerns toward achieving sustainable aquaculture. The purpose of this study was to see how early mild stress (netting) and FM replacement with meat and bone meal (MBM) affected oscar (Astronotus ocellatus; 5.2 ± 0.9 g) growth, hematology, blood biochemistry, immune responses, antioxidant system, liver enzymes, and stress responses. Oscars were subjected to a 3 × 3 experimental design (three fish meal replacement levels: 250, 180 and 110 g/kg of FM in diets; three stress periods: 0-, 2- and 3-times early mild stress). After ten weeks of the experiment, FM levels in diets did not affect growth data, but the survival rate after the acute confinement (AC) stress was lower in 11FM treatments (47.7% compared to 67.7%) than others. Fish exposed to the 3Stress schedule had a lower growth (31.03 ± 6.50 g) and survival rate (55.5%) after the AC stress than the 2Stress group (38.92 ± 6.82 g and 70.0%). Lower survival and growth rate in the 3Stress and 11FM groups coincided with the lowest blood performance, total protein, lysozyme, complement C4, complement C3, immunoglobulin, superoxide dismutase, catalase, glutathione peroxidase, and the highest glucose, cortisol, low-density lipoprotein and aspartate aminotransferase serum levels. Altogether, this study revealed that it is possible to replace FM with MBM up to 28% (180 g/kg of FM) without negative effects on the growth and health of juvenile oscar as dietary 110 g/kg of FM impaired fish health. While fish welfare should be considered, we can conclude that mild stress (2Stress) during the farming period, but without adding excessive alternative protein sources, can improve the stress responsiveness of oscar.

English

A 12-week feeding trial was conducted to evaluate the effects of replacing fishmeal with black soldier fly larvae (BSFL) meal on growth performance and carcass composition of African catfish fingerlings. Five isonitrogenous (40% CP) diets of 0 (Control), 25, 50, 75 and 100% fishmeal with BSFL were used in triplicate. A randomized complete block design was used, and 600 fingerlings (0.46&plusmn;0.02g) were randomly selected and stocked at a rate of 40 fingerlings in 15 plastic tanks respectively. Results showed that the treatment diets significantly (P&lt;0.05) affected growth indexes, feed utilisation indices, and carcass composition of fish. Furthermore, 25% fishmeal could be replaced by BSFL meal without significantly reducing growth indexes and feed utilisation indices. However, water quality and condition factors between treatments were not significantly (P&gt;0.05) affected by the diets. Decreased concentration of crude protein, ash, nitrogen free extracts in carcass composition of fingerlings with corresponding increase in dietary BSFL meal inclusion was observed. Increasing inclusion levels of BSFL meal and decreasing levels of fishmeal increased the concentration of ether extracts and fibre contents of the body composition. Therefore, BSFL meal protein can be used to partially replace fish meal up to 25% to improve growth performance and feed utilisation. Key words: Feed utilization, fishmeal, indices, insect meal, proximate analysis.

Effects of poultry by-product meal replacing fish meal on growth performance, feed utilization, intestinal morphology and microbiota communities in juvenile large yellow croaker (Larimichthys crocea)

An 8 weeks feeding trail was conducted to evaluate the potential of poultry by-product meal (PBM) replacing fish meal (FM) in the diet of juvenile large yellow croaker (Larimichthys crocea). Five iso-nitrogenous (45% crude protein), iso-lipidic (10% crude lipid) and iso-energetic (about kcal 400 g diet −1) diets were formulated with 0, 25%, 50% 75% and 100% FM being replaced by PBM (marked as FM, PBM25, PBM50, PBM75 and PBM100). Crystal methionine and lysine were added into PBM-containing diets to match its concentration in FM diet. Each diet was randomly assigned to triplicate groups of 30 fish (initial weight 18.43 ± 1.28 g) in floating sea cages. The weight gain, specific growth rate and feed efficiency of L. crocea decreased significantly when the replacement level of FM was higher than 25%. The feed intake of fish fed PBM100 was significantly lower than those fed FM, PBM25 and PBM50. Juveniles fed PBM-containing diets showed significantly lower value of muscular thickness in intestine when compared to those fed FM. Villi length decreased significantly when the replacement of FM in diets was more than 50%. Fish fed FM diet had the relative higher abundances of Exiguobacterium (from order to genus), Bacillus (from order to genus), Pseudomonadales (from order to genus) and Acinetobacter genus, those fed PBM25, PBM50 and/or PBM75 showed higher abundance of Peptostreptococcaceae and Vibrio. Overall, PBM replacing dietary FM may inhibit growth performance of L. crocea through reducing digestibility via declining the abundance of intestinal bacteria that producing digestive enzyme, and improving the abundance of pathogen. Peptostreptococcaceae and Vibrio could be the indicator in the intestinal of L. crocea fed high PBM diets. The optimum dietary FM replacement level by PBM was 25% for L. crocea.

Transcriptomic Analysis of Liver in Silver sillago, Sillago sihama Fed with High-Level Low-Gossypol Cottonseed Meal in Replacement of Fishmeal Diet

Understanding the molecular mechanisms involved in adaptation to alternate diets has become a significant concern, as increasing amounts of fishmeal (FM) protein in aquafeeds are being substituted with plant protein. Thus, the goal of this study was to assess growth performance, quality, and liver function of juvenile Sillago sihama (S. sihama) through growth indices, whole-body composition, histology of the liver, and RNA-sequencing (RNA-seq), after they were fed a formulated diet with 64% low-gossypol cottonseed meal (LCSM) for 56 days, compared to those fed a traditional FM-based diet. Indicators of growth, including final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER), and condition factor (CF), were considerably lower in the 64% LCSM (R64) group than in the FM diet group. In the R64 diet, the whole crude lipid was significantly lower than in the FM diet. The hematoxylin-eosin section showed that dietary high levels of LCSM resulted in diffuse lipid vacuolation in the liver of S. sihama. According to a liver transcriptome analysis, high LCSM intake in the diet significantly impacted lipid synthesis and catabolism, elevated pathways for cholesterol synthesis, blocked several amino acid metabolic pathways, and adversely affected hepatic gluconeogenesis and glycolysis. The findings of this study indicate that feeding high levels of LCSM in S. sihama is harmful to the growth of the organism and can harm the liver's structural integrity, as well as obstruct the normal metabolism of amino acids, lipids, and carbohydrates. Therefore, it is not recommended to substitute LCSM for high levels of FM in the diet of S. sihama.

Effects of Fishmeal Replacement by Clostridium Autoethanogenum Protein Meal on Cholesterol Bile Acid Metabolism, Antioxidant Capacity, Hepatic and Intestinal Health of Pearl Gentian Grouper (Epinephelus Fuscoguttatus ♀ × Epinephelus Lanceolatus ♂)

In this study, we present data from an eight-week growth trial with pearl gentian grouper fed either a reference diet (FM) with a fishmeal level of 50%, or test diet wherein 15% (CAP15), 30% (CAP30), 45% (CAP45), and 60% (CAP60) fishmeal was replaced by Clostridium autoethanogenum protein meal (CAP). Results showed that the weight gain and daily feed intake ratio of CAP60 were significantly lower than the FM group. In the serum, compared to the FM group, the content of malondialdehyde (MDA), the activities of alanine aminotransferase in CAP60 and CAP45 groups, and acid phosphatase in the CAP60 group were significantly higher, while the content of total cholesterol in CAP60 and CAP45 groups was significantly lower. In the liver, compared to the control group, the content of MDA in the CAP60 group was significantly higher. 3-hydroxy-3-methylglutaryl coenzyme A reductase in CAP30 to CAP60 groups and farnesoid X receptor in CAP60 were significantly upregulated. In distal intestines, the activities of trypsin and superoxide dismutase of CAP30 to CAP60 groups were significantly lower than the FM group. In conclusion, for pearl gentian grouper, CAP could replace up to 45% of the fishmeal in the feed, while a 60% replacement level will affect cholesterol bile acid metabolism and health.

Substitution effect of fish meal with meat meal in diet on growth performance, feed consumption, feed utilization, chemical composition, hematology, and innate immune responses of rockfish (Sebastes schlegeli)

Fish meal (FM) is widely used as a main protein source in formulated feed for marine fish culture. However, the production of FM has shrunk or plateaued due to the overfishing and climate change in the wild. Meat meal (MM) is known as a good replacer for FM in fish feeds. Dietary replacement effect of MM for FM on the growth, feed consumption, feed utilization, body composition, hematology, and innate immune responses of rockfish was determined. A total of 630 fish (initial weight of 2.3 g) was randomly distributed into 21, 50 L flow-through tanks (30 fish/tank). Seven experimental diets were formulated. The control (MM0) diet contained 55% FM. Then, 10, 20, 40, 60, 80, and 100% FM in the MM0 diet were replaced with MM, referred to as the MM10, MM20, MM40, MM60, MM80, and MM100 diets, respectively. All experimental diets were allocated to triplicate groups of fish. Fish were hand-fed to visual satiation twice a day for 8 weeks. Increased substitution of FM with MM in diets resulted in decreased essential amino acids (EAA), such as lysine and threonine and the sum n-3 highly unsaturated fatty acids, but increased EAA, such as arginine and methionine, and the sums of saturated and monoene FA. Weight gain (9.8 g/fish) of fish fed the MM10 diet was significantly (P < .003) greater than that (8.8, 8.9, 8.2, and 7.9 g/fish, respectively) of fish fed the MM0, MM60, MM80, and MM100 diets. Specific growth rate (SGR) (2.93%/day) of fish fed the MM10 diet was significantly (P < .004) higher than that (2.79, 2.69, and 2.64%/day, respectively) of fish fed the MM0, MM80, and MM100 diets. Weight gain and SGR of fish fed the MM100 diet were (P < .05) significantly lower than those of fish fed the MM0 diet. Feed consumption (9.34 g/fish) of fish fed the MM10 diet was significantly (P < .002) higher than that (8.72, 8.59, 8.32, and 8.10 g/fish, respectively) of fish fed the MM0, MM60, MM80, and MM100 diets. Feed efficiency (1.04%) of fish fed the MM10, MM40, and MM60 diets was significantly (P < .009) higher than that (0.99, and 0.98%, respectively) of fish fed the MM80, and MM100 diets. Condition factor, protein efficiency ratio, protein retention, hematological parameters, and innate immune responses (lysozyme and superoxide dismutase activities) of fish was not significantly (P > .05) different among the experimental diets. The chemical composition, and AA and FA profiles of the whole-body fish were not influenced by the experimental diets. In conclusion, dietary substitution FM up to 80% with MM can be made without deteriorating growth performance of rockfish. However, the optimum substitution level of FM with MM in diets were estimated to be 18.5, and 18.2% based on regression analysis of weight gain and SGR of rockfish, respectively.

Curcumin Supplementation Enhances the Feeding and Growth of Largemouth Bass (Micropterus salmoides) Fed the Diet Containing 80 g/kg Fish Meal

Two feeding trials were conducted to evaluate the influence of dietary curcumin level on fish meal replacement with poultry by-product (PBM) in a largemouth bass (Micropterus salmoides) diet. In trial I, the reference diet (R) contained 400 g/kg fish meal, and PBM replaced 60 and 80% of the fish meal (P16 and P8). In trial II, the diet containing 80 g/kg fish meal (P8) served as control (C), and curcumin was added at 5000 and 10000 mg/kg (C5 and C10), respectively. Replacement of fish meal with PBM significantly influenced feed intake, phosphorus retention efficiency (PRE), body lipid content, the ratio of fish meal consumption to fish production (RCP), and wastes of carbon and phosphorus but did not result in significant alternation in weight gain, feed conversion ratio (FCR), retention efficiencies of nitrogen (NRE), carbon (CRE) and energy (ERE), viscerosomatic index (VSI), hepatosomatic index (HSI), and body composition. The RCP, body lipid content, and phosphorus waste were higher in fish fed diet R than in fish fed diets P16 and P8. Curcumin supplementation influenced weight gain, feed intake, FCR, carbon waste, and RCP, but did not result in significant alternation in CRE, NRE, PRE, ERE, condition factor, VSI, HSI, body composition, and nitrogen and phosphorus wastes. The weight gain and feed intake were higher in fish fed diet C10 than in fish fed diet C, while the carbon waste was higher in fish fed diets C5 and C10 than in fish fed diet C. Overall, the minimum dietary fish meal level for largemouth bass could be dropped to 80 g/kg when PBM was used as an alternative ingredient, and 10000 mg/kg curcumin could obviously improve growth of fish fed diet containing 80 g/kg fish meal.

The Effect of using different levels of Fishmeal on growth and carcass performance Characteristics of broiler Chickens

سعى هذا البحث إلى تنفيذ تجربة تسمين على 4 معاملات من الدجاج اللاحم من سلالة الهابرد من عمر 7-35 يوما، وتكونت كل معاملة من 3 مكررات، وكل مكرر 10 طيور، بمجموع 120 طيرا في حضيرة التجارب التابعة لكلية الزراعة والطب البيطري في جامعة ذمار؛ بهدف معرفة استخدام مستويات مختلفة من مسحوق السمك على صفات أداء النمو والذبيحة في الدجاج اللاحم وقسمت التجربة إلى المعاملة الأولى التي استخدمت فيها كسبة فول الصويا بدون مسحوق السمك، والمعاملة الثانية تم استخدام 2% من مسحوق السمك، والثالثة تم استخدام 4% من مسحوق السمك، والمعاملة الرابعة تم استخدام 6% من مسحوق السمك، إلى جانب كسبة فول الصويا في علائق البادي (7-12 يوما)، والنامي (21-35 يوما). وبينت نتائج هذه التجربة عدم وجود فروق معنوية لمسحوق السمك على صفات النمو في المدة الأولى (7-21 يوما)، والثانية (21-35 يوما)، بين طيور جميع معاملات التجربة. في هذه التجربة بينت النتائج خلال المدة الكلية للتجربة (7-35 يوما) أن استخدام مسحوق السمك بنسبة 4% و6% في عليقة طيور المعاملات الثالثة والرابعة على التوالي قد أدى إلى زيادة معنوية في الوزن الحي النهائي والزيادة الوزنية الكلية وكمية العلف المستهلكة (جم/طير)، مقارنة بطيور المعاملة الثانية التي تغذت على عليقة فيها 2% من مسحوق السمك، كذلك أظهرت طيور المعاملة الثالثة والرابعة وزن ذبيحة أعلى معنويات مقارنة بطيور المعاملة الثانية.

Two-Stage Fermented Feather Meal-Soybean Meal Product Improves the Performance and Immunity of Lactating Sows and Piglets

This study aimed to investigate the effects of a two-stage fermented feather meal-soybean meal product (TSFP) on the performance, clinical blood biochemistry, and immunity of sows and piglets. TSFP was fermented by Saccharomyces cerevisiae Y10 for three days in the second stage, which showed similar results to the five-day fermentation of B. coagulans (p &gt; 0.05). Fifty hybrid sows (Duroc × KHAPS black pig) were randomly assigned into dietary supplementation groups of 2% fish meal or different levels of TSFP at 0%, 1%, 2%, or 3%. The results showed that body weight gain and feed conversion ratio of 2% and 3% TSFP groups were better than the control group and fish meal group during the gestation period (d 80–114) (p &lt; 0.05). During the lactation period, the 3% TSFP group showed the best weaning litter weight (p &lt; 0.05). In sows, interferon-γ and immunoglobulin G (IgG) of 2% and 3% TSFP groups were higher than the control group and fish meal group (p &lt; 0.05). In piglets, in groups of 2% and 3% TSFP blood urea decreased (p &lt; 0.05). The IgG of fermented groups was superior to the control group (p &lt; 0.05). The oxidative burst of phagocytes in the 3% TSFP was higher than those of the control and fish meal groups (p &lt; 0.05). In conclusion, TSFP supplementation exhibits the advantages of performance and immunity of lactating sows and piglets. Furthermore, adding 3% TSFP in the feed showed the best performance.

Dietary Fish Meal Level and a Package of Choline, β-Glucan, and Nucleotides Modulate Gut Function, Microbiota, and Health in Atlantic Salmon (Salmo salar, L.).

Steatosis and inflammation have been common gut symptoms in Atlantic salmon fed plant rich diets. Choline has recently been identified as essential for salmon in seawater, and β-glucan and nucleotides are frequently used to prevent inflammation. The study is aimed at documenting whether increased fishmeal (FM) levels (8 levels from 0 to 40%) and supplementation (Suppl) with a mixture of choline (3.0 g/kg), β-glucan (0.5 g/kg), and nucleotides (0.5 g/kg) might reduce the symptoms. Salmon (186 g) were fed for 62 days in 16 saltwater tanks before samples were taken from 12 fish per tank for observation of biochemical, molecular, metabolome, and microbiome indicators of function and health. Steatosis but no inflammation was observed. Lipid digestibility increased and steatosis decreased with increasing FM levels and supplementation, seemingly related to choline level. Blood metabolites confirmed this picture. Genes in intestinal tissue affected by FM levels are mainly involved in metabolic and structural functions. Only a few are immune genes. The supplement reduced these FM effects. In gut digesta, increasing FM levels increased microbial richness and diversity, and changed the composition, but only for unsupplemented diets. An average choline requirement of 3.5 g/kg was indicated for Atlantic salmon at the present life stage and under the present condition.

Effects of Crab Shellmeal Inclusions to Fishmeal Replacement on the Survival, Growth, and Feed Utilization of Mangrove Crab Scylla serrata (Forsskal 1775)

Mangrove crab Scylla serrata is associated with mangroves throughout the Indian and Pacific oceans. This species is crucial to aquaculture and fishing. As wild stocks decline and demand rises, mangrove crab aquaculture has become increasingly popular. However, feed development research and its quality are still meager in the industry. This study examined the interactive effects of different levels of crab shellmeal (CSM) to fishmeal (FM) replacement on proximate composition, feed utilization, carcass composition, growth, and survival performance of mangrove crab S. serrata. Four formulated diets were prepared, and one for chopped trash fish (TF) supplement: 30% FM and 0% CSM (Diet 1) as a negative control, 20% FM and 10% CSM (Diet 2), 10% FM and 20% CSM (Diet 3), 0% FM and 30% CSM (Diet 4), and TF as a positive control (Diet 5). Experiments were conducted in each group for 30 days with ten replicates. Results revealed that formulated diets using different levels of CSM and FM did not significantly affect mangrove crabs' growth and survival rates as well as feed utilization. However, the proximate composition of Diet 4 was significantly higher among other experimental diets. Moreover, the crab's whole body composition (ash, moisture, carbohydrates, crude protein, crude fat, and calories) with different levels of CSM and FM was significantly improved. Hence, it is possible to enhance the carcass composition and proximate composition by supplementing CSM; however, it has no effect on feed utilization, as well as the growth and survival rates of mangrove crab S. serrata.

Inclusion effect of jack mackerel meal as feed stimulants in diets replacing different levels of fish meal with various animal protein sources on growth performance of olive flounder (Paralichthys olivaceus)

Incorporated feed stimulants into fish feeds is a very sustainable aquaculture technique, especially in developing low FM diet to improve feed consumption and growth performance. This study aims to evaluate inclusion effect of jack mackerel meal (JMM) as feed stimulants in diets replacing different levels of FM with various animal protein sources on the growth, feed utilization, biochemical composition, and non-specific immune response of olive flounder (Paralichthys olivaceus). Two-way [3 substitution source; tuna by-product meal (TBM), chicken by-product meal (CBM), and meat meal (MM) × 2 substitution ratio; 25% and 50%] ANOVA experimental design was applied. Seven experimentally formulated diets were prepared. The control (Con) diet contained 60% FM. Twenty-five and 50% of FM in the Con diet were substituted with TBM, CBM, and MM when 12% JMM was included at the expense of FM, referred to as the TBM25, TBM50, CBM25, CBM50, MM25, and MM50 diets, respectively. All experimental diets were formulated to be isonitrogenous at 56.1% and isolipidic at 10.2%. Four hundred and twenty juvenile fish were randomly distributed into 21 flow-through tanks. Severn experimental diets were assigned to triplicate groups of fish. Both dietary substitution source and ratio had significant (P < 0.0001, P < 0.003, P < 0.0001, P < 0.003, P < 0.0001, and P < 0.0001, respectively) effects on weight gain, specific growth rate (SGR), and feed consumption of fish. Weight gain, SGR, and feed consumption of fish fed the Con diet was significantly (P < 0.0001) inferior to fish fed the TBM25, TBM50, and CBM25 diets. However, no significant (P > 0.05) difference in feed utilization, biochemical composition, and non-specific immune response of fish was observed among the experimental diets. Conclusively, TBM and CBM, and MM could be used as the proper substitutes for FM up to 50%, and 25%, respectively in olive flounder feeds with inclusion of JMM as feed stimulants.

Dietary sulfate-based alginate polysaccharide supplementation boosts growth, gut health, immune response and disease resistance in juvenile hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatus) fed cottonseed protein concentrate-based diets

To study the dietary prebiotic role of Sulfate-Based alginate polysaccharide (SAP) in cottonseed protein concentrate-based diets, six iso-nitrogenous and iso-lipid feeds were prepared to feed grouper, including a fishmeal control group (FM) was set at 50% fishmeal level, on this basis 5 groups replacing 50% fishmeal protein with cottonseed protein concentrate and supplementing sulfate-based alginate polysaccharide 0%, 1%, 2%, 3% and 4% (SAP0, SAP1, SAP2, SAP3 and SAP4 groups). The healthy and vigorous grouper (initial weight = 8.63 ± 0.01 g) were selected and randomly divided into 6 treatment groups in triplicates (30 fish in each repetition). The feeding experiment was conducted for 8 weeks, followed by a one-week Vibrio harveyi challenge. The experimental results showed that the weight gain and specific growth rate reached the significant maximums in SAP2 and SAP3 groups (P < 0.05). The malondialdehyde and triglyceride levels in serum decreased, while the antioxidant indicators and non-specific immune enzymes activity (lysozyme, acid phosphatase, alkaline phosphatase) in serum and intestinal tissue got increased (P < 0.05). The intestinal digestive enzymes activity and histomorphology indices (plica height, plica width and muscle layer thickness) were increased (P < 0.05). Microbial sequencing revealed that the ACE and Chao1 indices increase firstly and then decreased, while the Shannon and Simpson indices showed a decreasing trend (P < 0.05). The expression level of pro-inflammatory factors (IL-1β and TNF-α) was down-regulated, yet the expression of anti-inflammatory factors (IL-10) was up-regulated in intestinal tissue (P < 0.05). The cumulative mortality of Vibrio harveyi challenge was significantly reduced (P < 0.05). In one word, the adverse effects on growth, immunity and intestinal health of grouper feeding cottonseed protein concentrate-based diets were repaired by the supplementing sulfate-based alginate polysaccharide. According to the binary regression analysis of specific growth rate among SAPs treatments, the optimum level of supplementing sulfate-based alginate polysaccharide of grouper was 2.25%.

Optimal Levels of Fish Meal and Methionine in Diets for Juvenile Litopenaeus vannamei to Support Maximum Growth Performance with Economic Efficiency.

This work investigated the optimal levels of fish meal (FML) and dietary methionine (Met) required for maximum growth performance of juvenile Litopenaeus vannamei with economic efficiency. Four sets of diets were prepared to contain 0.00, 6.00, 12.00 and 18.00% FML. Each set was supplemented with DL-methionyl-DL-methionine (DL-Met-Met) to result in a total dietary Met (Met + Cys) content of 0.58 (1.05), 0.69 (1.16), and 0.82% (1.29%), on a fed basis. Shrimp of 1.00 ± 0.08 g were stocked in 60 outdoor tanks of 1 m3 with 100 shrimp/m2, allowing five replications per dietary group. Shrimp in all the groups were fed 10 times daily for 70 days. In a subsequent trial, dietary protein and amino acid digestibility of four FML groups, but only at high dietary Met levels (~0.82%), were evaluated in 40 60 L indoor tanks (11 replicates per diet) for 93 days with 70 shrimp/m2. Final shrimp survival (92.85 ± 4.82%, mean ± standard deviation), weekly weight gain (1.17 ± 0.08 g), apparent feed intake (13.3 ± 0.5 g of feed per stocked shrimp), and feed conversion ratio (1.18 ± 0.06) were unaffected by dietary FML level and Met content. Gained yield was adversely affected when FML was reduced from 18 and 12% (1156 and 1167 g/m2, respectively) to 0 (1090 g/m2), but no change was observed at 6% (1121 g/m2). A significant interaction was detected between FML level and dietary Met. Under 0 and 6% FML conditions, higher levels of total dietary Met, 0.69 and 0.82%, respectively, were required to maximize shrimp BW. In comparison, at 12 and 18% FML, a dietary Met content of only 0.58% was sufficient. Overall, results indicated the use of FML can be minimized or completely eliminated without major detrimental effects on feed digestibility or shrimp growth performance, as long as proper supplementation of Met is carried out. Diets with 0 FML or with only 6% delivered the highest profit and return on investment compared to diets with higher levels.