Apparent Digestibility Coefficients Of Nutrients Research Articles

Use of Cracker Residue in the Diet of Dairy Heifers: Impacts on Animal Health, Ruminal Fatty Acids Profile, Digestibility, Weight Gain, and Economic Viability.

This study determined whether the isomeric or isoenergetic/isoproteic substitution of corn in the diet of Jersey heifers in the rearing phase with cracker residue would impair growth and health, as well as reducing production costs. Fourteen Jersey females in the growth phase were used, separated into two treatments with seven animals in each lot in collective pens. The experiment used 7-month-old animals (169.8 ± 2.89 kg) and lasted for four months. In Experiment I, the animals were divided into two groups: treatment, with the partial replacement of 40% corn with cracker residue, and control, in which the animals consumed the same diet with 100% corn (isometric diet kg for kg). In Experiment II, the animals with a body weight of 200.2 ± 3.85 kg were divided into two groups: Treatment, replacing 100% of the corn with cracker residue, and control, in which the animals consumed an isoprotein and isoenergetic diet but with 100% of the corn in the formulation. The diet consisted of concentrate, Tifton 85 hay, and corn silage, supplied twice a day individually, with animals contained in their feeders by kennels. There was water ad libitum in the bay. Biweekly weighing and monthly blood analysis were performed, totaling four collections per part for hematologic evaluation, carbohydrate, lipid, and protein metabolism variables. At the end of each experiment, ruminal fluid was collected to measure the volatile fatty acid profile, and feces were collected to determine the apparent digestibility coefficient (ADC). Experiments I and II showed no effect of treatment on body weight, weight gain, average daily weight gain, feed intake, and feed efficiency. There was no effect of treatment on leukocyte, erythrocyte, lymphocyte, neutrophil, monocyte, and eosinophil counts, hematocrit, and hemoglobin concentration (p > 0.05). Experiment I showed a difference between groups for the variables albumin, globulin, total proteins, cholesterol, glucose, and urea, which did not happen in Experiment II. In both experiments, a higher ADC of nutrients was found in the treatment group which had cracker residue (p > 0.05). The concentration of volatile fatty acids in Experiment I was higher in the control group, unlike in Experiment II, where the highest concentration was in the treatment group (p > 0.05). Because experiment I had an isometric substitution, the diets had different bromatological composition, which is the probable cause of the difference between groups; this did not happen in experiment II, in which the diets consumed by the animals was isoproteic and isoenergetic. Based on these data we conclude that the substitution of cracker residue in an isomeric or isoenergetic/isoproteic form does not negatively affect weight gain and animal health, as well as reduces the cost of the concentrate, consequently reducing the cost of production of these animals.

Effects of Increasing Levels of Purified Beta-1,3/1,6-Glucans on the Fecal Microbiome, Digestibility, and Immunity Variables of Healthy Adult Dogs.

Yeast-purified beta-1,3/1,6-glucans (BG) can modulate dogs' immune systems and microbiome, but the optimal inclusion dose remains unknown. The aim of the study was to evaluate the effects of 0.0, 0.07, 0.14, and 0.28% inclusion of BG in a dry extruded diet on the digestibility, immunity, and fecal microbiota of healthy adult dogs. Eight male and female border collies [n = 4; body condition score (BCS) = 5] and English cocker spaniels (n = 4; BCS = 5), aged 3.5 ± 0.5 years, were randomly distributed into two 4 × 4 balanced Latin squares. Fecal microbiota (using 16S rRNA sequencing, Illumina®), apparent digestibility coefficients (ADC) of nutrients, fecal concentrations of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA), ammoniacal nitrogen, lactic acid, IgA and pH, lymphocyte immunophenotyping, intensity and percentage of phagocytosis and oxidative burst were determined. No differences were observed in Faith (p = 0.1414) and Pielou-evenness (p = 0.1151) between treatments, but beta diversity was different between 0.0% and 0.14% BG groups (p = 0.047). Moreover, the Firmicutes phylum was the most abundant in all groups and exhibited the highest relative abundance after the consumption of 0.14% BG, a finding considered beneficial for the canine microbiome. The Erysipelotrichaceae and Ruminococcaceae families, along with the Faecalibacterium and Prevotella genera, considered favorable for their involvement in butyrate production and other metabolites, showed increased abundance after the consumption of 0.14% BG. The potentially pathogenic Proteobacteria phylum displayed lower abundance after the consumption of 0.14% BG. Fecal concentrations of the evaluated compounds and pH did not differ after consumption of the BG at all percentages. Higher crude protein ADC was found after 0.14 and 0.28% BG consumption (p < 0.0001), but no differences were found for other nutrients. Phagocytosis, oxidative burst, and lymphocyte populations were not modulated by any of the treatments; however, 0.14% BG modulated the lymphocyte T CD4+:CD8+ ratio (p = 0.0368), an important marker of immune system efficiency. The inclusion of 0.14% BG resulted in the best responses and was the best dose evaluated.

Digestible energy content and apparent digestibility coefficients of fish meal, soybean meal, corn, wheat middlings and soybean oil in paiche Arapaima gigas

A balanced feed will optimize the performance and nutrient utilization of the paiche according to its genetic potential. Information is required regarding the nutritive value of the ingredients and the bioavailability of the nutrients. For this reason, and given the limited information available, the objective of this research was to determine the apparent digestibility coefficients of nutrients and digestible energy of fish meal, soybean meal, corn, wheat middlings and soybean oil through the indirect method using chromic oxide as an inert marker. The apparent digestibility of dry matter ranged from 49 % -87 %, protein ranged from 68-90 %, lipids ranged from 73-93 % and energy ranged from 54-97 % for the different ingredients tested. The digestible energy of the fish meal was determined to be 4.34 Mcal.DE/kg. Soybean meal, corn, wheat middlings and soybean oil had values of 3.67 Mcal.DE/kg, 2.63 Mcal.DE/kg, 2.24 Mcal.DE/kg and 9.19 Mcal. DE/kg. Knowledge of the digestibility of nutrients will allow the development of feeds for the paiche with ingredients of greater digestibility, allowing to increase the productive performance of the paiche, the reduction of feeding costs resulting in the improvement of the profitability of fish farmers for a sustainable activity.

Complete Replacement of Fish Meal with Potential Aquafeed Ingredients for Rainbow Trout in Iran

Iran, as one of the largest rainbow trout producers in the world, needs sustainable aquafeed resources to fulfill the requirements of this growing industry. Therefore, locally available canola meal, feather meal, blood meal and poultry by-product meal were evaluated on their suitability for feeding rainbow trout. Fish growth performance and apparent digestibility coefficients (ADCs) of nutrients were investigated for three casein-based fish meal-free diets, a practical feed including 10% spray-dried blood meal, 22% poultry by-product meal, 10% feather meal (GOLDMEHL®), 10% canola meal and 15.5% wheat flour in comparison to a commercial diet containing fish meal. The diets were allocated to aquaria in three replicates arranged in a random-block-design. Findings of the present study illustrated that growth performance remained unchanged (p&gt;0.05) among fish fed fish meal-free diets and the commercial one. Formulating aquafeed using properly processed local feed ingredients such as poultry slaughterhouse by-products, canola meal, and crystalline amino acids can provide a sustainable solution to meet the feed requirements of the growing aquaculture industry on a regional scale. This research shows the potential for using locally available resources in aquafeed manufacturing.

Performances and nutritional values of a new hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) as hay or silage for sheep under Mediterranean conditions

The hooded barley phenotype produces an extra sterile flower in spikelets instead of awns. Hence, it might improve the nutritive value of the whole plant. The aim of this work was to evaluate a new variety of hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) harvested and processed as hay and silage during 2 consecutive years for sheep. Digestibility was determined using 32 ewes which were distributed in 2 balanced groups by treatment, and fed with hay and silage sequentially. Results showed differences in the chemical composition of hay and silage according to harvesting year, but no differences were found on voluntary intake by year, species, or their interaction. Both forages showed high sheep fill values (sFV) either as hay or as silage (2.65 ± 0.030 and 3.09 ± 0.042 sFV/kg DM, on average, respectively). Impact on apparent nutrient digestibility coefficients varied according to preservation method, the digestibility of hays being mainly affected by the harvesting year, and that of silages by species. Digestible undegradable protein values were greater in hooded barley than in triticale for silages. In conclusion, marked compositional differences between years, but slight differences between species, were observed. Consequently, intake was similar, although triticale revealed slightly greater nutritive values than hooded barley. The obtained values for hooded barley as forage were greater than those reported in the literature for common fodder barley.

Methanotroph (Methylococcus capsulatus, Bath) bacteria meal alleviates soybean meal-induced enteritis in spotted seabass (Lateolabrax maculatus) by modulating immune responses and the intestinal flora

The effect of methanotroph (Methylococcus capsulatus, Bath) bacteria meal (FeedKind®, FK) supplementation in a high-soybean meal diet on growth, non-specific immunity, and gut health in spotted seabass (Lateolabrax maculatus) was investigated. Six experimental diets were formulated: control (containing 38% fish meal, FM, and 16.5% soybean meal, SBM), a high-soybean meal diet (containing 28% FM and 35% SBM), and four experimental diets each containing 28% FM and 35% SBM with the addition of FK at 2% (FK2), 4% (FK4), 6% (FK6) or 8% (FK8) in the diet to replace wheat gluten. All diets also contained 0.1% yttrium oxide to determine apparent digestibility coefficients (ADCs) of dry matter, crude protein and crude lipid. Following a 14-day acclimation period, fish were fed the diets for 56 days. Results showed that the FK2 and FK4 groups showed significantly higher weight gain (WG) compared to the SBM group (P < 0.05), whilst the FK2, FK6, and FK8 groups showed higher WG compared to the FM group (P < 0.05). The FK2, FK4, and FK8 had lower feed conversion rate (FCR) compared to the SBM group (P < 0.05). No differences were noted in overall survival. Intestinal lipase activity was significantly increased in the FK2 and FK4 groups and trypsin activity was significantly increased in the FK2 group compared to the SBM group (P < 0.05). The FK2 group showed significantly higher apparent digestibility coefficients of nutrients than the SBM group (P < 0.05). The expressions of anti-inflammatory genes (tgfβ, il-4, and il-10) in the intestine of the FK-supplemented group showed a significant increment (P < 0.05), whilst the expressions of pro-inflammatory genes (tnfα, il-1β, and il-8) significantly decreased (P < 0.05). The results of 16S rRNA gene sequencing showed that indexes of alpha diversity in the SBM group were decreased (P < 0.05) compared with all other diets. In addition, the FK2 group showed significantly higher serum acid phosphatase (ACP), alkaline phosphatase (AKP), complement 4 (C4), and total protein (TP), levels than the SBM group (P < 0.05). Inclusion of FeedKind in high SBM diets alleviated SBM-induced intestinal inflammation by modulating the expression of intestinal inflammatory factors and regulating intestinal flora. Overall, supplementation of SBM diets with 2%–4% FK improved growth, non-specific immunity, and ADC's in spotted seabass.

The effects of a Bacillus licheniformis and phytase mixture added to broiler diets on growth performance, nutrient digestibility, and cecal microecosystem

Abstract This study aims to evaluate the effects of Bacillus licheniformis and 6-phytase added alone or in combination to broiler chicken diets on the growth performance, apparent ileal digestibility coefficient (AID) of nutrients, microbial activity, and cecal bacterial communities. In total, 400 one-day-old female Ross 308 chicks were randomly allocated to 4 dietary treatments (10 replicate pens, 10 birds each). The following groups were defined: NC (negative control), basal diet without any feed additive supplementation; NC+Pro, basal diet with addition of the B. licheniformis preparation (500 g/t of diet); NC+Phy, basal diet with addition of phytase (200 g/t of diet); and NC+Pro+Phy, basal diet combined with both studied additives. B. licheniformis positively affected (P&lt;0.05) the feed intake (FI) and feed conversion ratio (FCR) in the first 10 d of bird rearing. Moreover, phytase supplementation elevated the FCR from 21 to 35 d. In the entire experiment, an interaction between phytase and probiotic was observed only in terms of decreasing the bird FI (P=0.005) without a negative effect on the FCR (P&gt;0.05). Furthermore, the AID of ether extract was improved by phytase supplementation. In terms of the cecal microecology, both separately administered factors promoted Lactobacillaceae in the ceca. Interactions between probiotic preparation and phytase were noted that indicated a decreased Clostridiales population and favored Ruminococcaceae proliferation. It can be concluded that for the first time in the available literature, the favorable interactions between B. licheniformis and phytase resulted in improved performance and cecal microbiota changes in broilers.

Partial dietary fishmeal replacement with mixture of plant protein sources supplemented with exogenous enzymes modify growth performance, digestibility, intestinal morphology, haemato-biochemical and immune responses for Nile tilapia, Oreochromis niloticus

For the aquaculture sector, expanding the amount of plant proteins substituting fish meal (FM) is favorable. This study was conducted to evaluate the properties of diets containing a blend of plant protein sources (cotton seed meal, sunflower meal and jojoba (CSJ)) instead of FM and supplemented with a mixture of exogenous enzymes on the growth performance, intestinal morphology, blood indices, activity of endogenous and digestibility also, immune response of Nile tilapia, Oreochromis niloticus. Three groups of the experimental diet (29.5% crude protein) and (18.76 MJ kg −1 gross energy) were performed. The first group CSJ1 was (FM: CSJ = 2:1), the second group diet CSJ2 was (FM: CSM = 2:2) and the third CSJ3 was (FM: CSJ = 2:1), the replaced was based on content of protein. All groups of diets were supplemented with mixture of enzymes (Protease, pepsin, trypsin, xylanase and amylase) at 0 and 0.5 g kg −1 diet therefore six diet was formulated. Fingerlings (6.30 ± 0.09 g) were randomly allocated into eighteen plastic tank (450 L capacity) in triplicate per each treatment (25 fish/ treatment) for 90 days. After 90-days of the feeding trial, results indicated that the highest wight gain and best FCR, higher (P < 0.05) activity of trypsin and lipase, apparent digestibility coefficient of nutrients were detected in fish fed diet of FM: CSJ 2:1 and 2:2 supplemented with 0.5 g enzymes mixture kg−1 diet with insignificant differences between group. The diet incorporating FM: CSJ 2:1 with 0.5 g enzymes mixture showed the maximum (P < 0.05) villi length/width, ASA, and MSR values. Fish fed a diet containing FM: CSJ 1:2, and supplemented with 0.5 g of an enzyme mixture kg−1 diet had the maximum Hb, Htc, RBCs and WBCs values (P < 0.05). The highest (P < 0.05) TP and GL value was estimated in diet containing FM: CSJ; 1:2 without the addition of enzymes mixture. while, the best (P < 0.05) value of ALT and AST were showed in diet containing FM: CSJ 2:1 without the addition of enzymes. The highest TAC, GSH and SOD values were recorded by fish fed diet containing FM: CSJ 1:2 or 2:2 with 0.5 g enzymes mixture kg−1 diet. Fish fed diets comprising various ratios of FM: CSJ with 0.5 g enzymes mixture kg−1 diet had the lowest (P < 0.05) MDA value. In conclusion, using mixture of enzymes (protease, pepsin, trypsin, xylanase and amylase) at 0.5 g kg−1 in combination with a high blend of CSJ instead of FM; 2:2 improved the growth performance, digestibility, digestive enzyme, intestinal morphology, blood indices, and immune response of Nile tilapia.

Composition and apparent digestibility coefficients of essential nutrients and energy of cyanobacterium meal produced from Spirulina (Arthrospira platensis) for freshwater-phase Atlantic salmon (Salmo salar L.) pre-smolts

Composition and apparent digestibility coefficients (ADCs) were determined for whole-cell Spirulina meal produced from Arthrospira platensis (UTEX LB 2340). Spirulina meal contained 60 % crude protein, 20 MJ kg−1 gross energy, 16 % nitrogen-free extract (NFE), 10 % ash, 5 % moisture and 4 % crude lipid. Its protein was comprised of 25 % essential (EAAs) and 25 % non-EAAs. Spirulina meal protein demonstrated high EAA indices (1.0–1.3) relative to egg albumin and premium fishmeal. Spirulina meal was rich (mg 100 g−1) in chlorophyll a (1803) and c (369), β-carotene (141) and zeaxanthin (88) with low concentrations of antinutritional compounds crude fibre (4 %), trypsin inhibition activity (7 TUI mg−1) and phytate (17 mg g−1/ g) and undetectable heavy metal contaminants. A substitution digestion assay using cylindro-circular tanks (100L) equipped with faecal settlement columns was conducted with 164 juvenile (25 g) freshwater Atlantic salmon (Salmo salar L.) at 13 °C fed to apparent satiation with a reference diet (100 % basal mixture) or a test diet (80 % basal mixture and 20 % test ingredient) for 7 weeks. Single-ingredient ADCs for Spirulina meal were dry matter (75 %), ash (61 %), protein (81 %), lipid (73 %), NFE (63 %), energy (77 %), EAAs (average 91 %) and polyunsaturated fatty acids (PUFAs, 96 %). Digestible indispensable AA scores (DIAAS) for Spirulina meal were equal to or higher than 1 (range 1.0–4.6) showing Spirulina meal to be a high-quality protein for Atlantic salmon. Diet ADCs for the 20 % Spirulina meal diet were statistically the same as the reference diet for dry matter (73–74 %), ash (36–41 %), crude lipid (93–94 %), NFE (23–32 %) and energy (82–83 %), while crude protein ADC was slightly reduced from 92 to 90 %. Inclusion of 20 % Spirulina meal had no significant effects on diet ADC for the required EAAs (93–98 %), n-6 PUFA (96 %), n-3 PUFA (100 %) or essential n-3 long-chain PUFAs eicosapentaenoic acid and docosahexaenoic acid (100 %).

Fish Viscera Silage: Production, Characterization, and Digestibility of Nutrients and Energy for Tambaqui Juveniles

Fish viscera can be an important source of protein and energy for aquafeed, and its use contributes to circular aquaculture. The aim of this study was to produce acid and fermented silage from fish viscera to determine their nutritional value and the apparent digestibility coefficient of nutrients and energy for juvenile tambaqui (Colossoma macropomum). An acid silage and three fermented silages with different sources of carbohydrates (molasses, wheat bran, and cassava waste) were produced with 0.25% sorbic acid as an antifungal in the formulation. Silages presented an average of 55% dry matter, 62.9% lipids, and 12% crude protein. Leucine and lysine predominated as essential amino acids in the acid silage and fermented silages. Fish viscera silages presented EPA and DHA content from 5.4 to 17.8 and 1.7 to 8.9 mg.g−1 of lipids, respectively. The apparent digestibility coefficient (ADC) (indirect method) was above 82% for gross energy for all the formulations. The ADCs for protein were similar for the fermented silages, with a maximum 92% level for the fermented wheat bran silage. The bioconversion of fish viscera into silage makes it an energy ingredient for aquafeed that is well digested by tambaqui juveniles.

Complexo enzimático comercial (AllzymeR) melhora a digestibilidade da ração para tilápias do Nilo em crescimento

ABSTRACT Recent studies have evidenced exogenous enzymes as nutritional tool to elaborate low-polluting aquafeeds. This study aimed to evaluate effects of enzyme complex (EC) on apparent digestibility coefficients (ADC) of energy and nutrients, including amino acids, as well nitrogen (N) and phosphorus (P) loss in pre-growout Nile tilapia (Oreochromis niloticus). Diets without EC (Control) or with EC supplemented at 225 (EC225) or 450 mg/kg diet (EC450) and fed to Nile tilapia (n = 135, 150 ± 20 g) distributed in an entirely randomized design of three treatments and three replicates of 15 fish each. Fish fed diet EC450 showed higher digestibility of energy, protein, amino acids and mineral, and increased digestible energy (DE; +221.25 kcal/kg diet), digestible protein (DP; +10.54 g/kg diet) contents of diets, whereas reduced N (−23.82%) and P (−18.46%) loss relative to fish fed diet control. This study evidenced that EC at 450 mg/kg diet optimizes the ADC of multiple nutrients, including amino acids, and identified its potential to enhance the nutritive value of feeds and elaborate sustainable feeds for Nile tilapia.

Effect of dietary soybean saponin Bb on the growth performance, intestinal nutrient absorption, morphology, microbiota, and immune response in juvenile Chinese soft-shelled turtle (Pelodiscus sinensis).

Soybean meal is widely applied in the aquafeeds due to the limitation of fish meal resources. Numerous studies have manifested that dietary soybean saponin, an anti-nutrient factor in soybean meal, may slow growth and induce intestinal inflammation in aquatic animals, but the possible causes are unclear. The juvenile Pelodiscus sinensis (mean initial body weight: 6.92 ± 0.03g) were fed basal diet (CON group) and 2.46% soybean saponin Bb-supplemented diet (SAP group) for 35 days to further explore the effects of dietary soybean saponin Bb on the growth performance, apparent digestibility coefficients, intestinal morphology, the gut microbiota, intestinal transporters/channels, and immune-related gene expression. The results indicated that dietary soybean saponin Bb significantly decreased final body weight, specific growth rate, protein deposition ratio, and apparent digestibility coefficients (dry matter, crude protein, and crude lipid) of nutrients in Pelodiscus sinensis, which may be closely correlated with markedly atrophic villus height and increased lamina propria width in the small intestine. In addition, plasma contents of cholesterol, calcium, phosphorus, potassium, lysozyme, and C3 were significantly decreased in the SAP group compared with the control group. Soybean saponin Bb significantly downregulated the mRNA levels of glucose transporter 2, fatty acid binding protein 1 and fatty acid binding protein 2, amino acid transporter 2, b0,+-type amino acid transporter 1, and sodium-dependent phosphate transport protein 2b in the small intestine. At the same time, the expressions of key transcription factors (STAT1, TBX21, FOS), chemokines (CCL3), cytokines (TNF-α, IL-8), and aquaporins (AQP3, AQP6) in the inflammatory response were increased by soybean saponin Bb in the large intestine of a turtle. Additionally, dietary supplementation of SAP significantly reduced the generic abundance of beneficial bacteria (Lactobacillus, Bifidobacterium, and Bacillus) and harmful bacteria (Helicobacter and Bacteroides). In a nutshell, dietary supplementation of 2.46% soybean saponin not only hindered the growth performance by negatively affecting the macronutrients absorption in the small intestine but also induced an inflammatory response in the large intestine possibly by damaging the intestinal morphology, disturbing the intestinal microbiota and decreasing intestinal epithelial cell membrane permeability.

Apparent digestibility of ten protein ingredients for largemouth bass ( Micropterus salmoides )

The study was conducted to investigate the apparent digestibility coefficients (ADC) of nutrients in commonly used protein sources for largemouth bass. A reference diet and test diets with 70% reference diet and 30% feedstuff were formulated with yttrium oxide as a digestibility indicator. Overall, the ADC of dry matter of tested protein ingredients was 69.5%–96.4%, and the ADC of dry matter in animal protein sources was significantly higher than in the other five plant protein sources. The ADC of crude proteins ranged from 89.1% to 97.3% for all tested feedstuffs. The ADC value of total amino acids in the tested ingredients is consistent with that of the protein. The ADC of crude lipid of tested ingredients ranged from 45.4% to 96.2%, and the lowest and highest values were observed in porcine haemoglobin powder and pet-grade poultry by-product meal, respectively. The ADC of total phosphorus of animal protein ingredients, except porcine haemoglobin powder, was significantly higher than that of plant protein ingredients, except fermented soybean meal. The results revealed the difference in availability of nutrients in plant and animal protein sources for largemouth bass, which could provide a theoretical basis for the selection of protein sources of commercial feed for largemouth bass.

Apparent Digestibility Coefficients of Black Soldier Fly (Hermetia illucens), Yellow Mealworm (Tenebrio molitor), and Blue Bottle Fly (Calliphora vicina) Insects for Juvenile African Catfish Hybrids (Clarias gariepinus × Heterobranchus longifilis).

A digestibility trial was conducted with African catfish hybrid juveniles in order to determine the apparent digestibility coefficients (ADCs) of different nutrients. The experimental diets contained defatted black soldier fly (BSL), yellow mealworm (MW), or fully fat blue bottle fly (BBF) meals, in a 70 : 30 ratio between the control diet and the tested insect meals. The indirect method for the digestibility study was performed using 0.1% yttrium oxide as an inert marker. Fish juveniles of 217.4 ± 9.5 g initial weight were distributed in 1 m3 tanks (75 fish/tank) of a recirculating aquaculture system (RAS), in triplicates, and fed until satiation for 18 days. The average final weight of the fish was 346 ± 35.8 g. The ADCs of the dry matter, protein, lipid, chitin, ash, phosphorus, amino acids, fatty acids, and gross energy for the test ingredients and diets were calculated. A six-month storage test was carried out to evaluate the shelf life of the experimental diets, while the peroxidation and microbiological status of the diets were also assessed. The ADC values of the test diets differed significantly (p < 0.001) compared to those of the control for most of the nutrients. Altogether, the BSL diet was significantly more digestible for protein, fat, ash, and phosphorus than the control diet but less digestible for essential amino acids. Significant differences were found between the ADCs of the different insect meals evaluated (p < 0.001) for practically all nutritional fractions analyzed. The African catfish hybrids were able to digest BSL and BBF more efficiently than MW, and the calculated ADC values agreed with those of other fish species. The lower ADCs of the tested MW meal correlated (p < 0.05) with the markedly higher acid detergent fiber (ADF) levels present in the MW meal and MW diet. Microbiological evaluation of the feeds revealed that mesophilic aerobic bacteria in the BSL feed were 2-3 orders of magnitude more abundant than those in the other diets and their numbers significantly increased during storage. Overall, BSL and BBF proved to be potential feed ingredients for African catfish juveniles and the shelf life of the produced diets with 30% inclusion of insect meal retained the required quality during a six-month period of storage.

Andrographolide loaded Pickering emulsion: A bioactive component for improved growth, digestibility, and haematological properties in cultured common carp Cyprinus carpio

In aquaculture, the therapeutic potential of andrographolide had been beneficially documented but still restricted owing to its high dosage and low bioavailability. To maximize andrographolide's potential value in carps, we want to create an effective delivery mechanism. During the 8-week Cyprinus carpio feeding trial, we aimed to test a low dose (0.05 g kg−1 or 0.005%) andrographolide-supplemented diet with or without a novel delivery system (chitosan particles stabilized Pickering emulsion). The experiment included four treatment groups, having a commercial carp feed as basal diet (control), diet containing Pickering emulsion without andrographolide encapsulation (PE), diet with free andrographolide (without Pickering emulsion) (AGL), diet with andrographolide encapsulated Pickering emulsion (AGL-PE). A significantly improved (p < 0.05) body weight, thermal growth coefficient and feed conversion ratio of the AGL-PE group was observed than control or AGL alone. It demonstrated improvement of AGL's efficacy may be brought by a proper delivery system. However, the delivery system alone (PE) did not significantly interfere with the results, as the differences of PE group were non-significant (p > 0.05) with either control or AGL group. The apparent digestibility coefficient of dietary nutrients, most notably protein, fiber, carbohydrates, and energy, had improved significantly (p < 0.05) by AGL-PE treatment compared to control. This most likely resulted in improved feed utilization and growth. AGL-PE addition in carp feed did not alter the ionic concentration of common blood electrolytes or metabolites, with the exception of nitrogen factors such as NH3, urea, and creatinine, possibly because of a higher digestible intake of nitrogen. Haemato-biological parameters showed a significant increase in lymphocyte, albumin, globulin, total protein, triacylglycerol with AGL-PE group (p > 0.05) than control supporting a stress free and strengthened immune system. Additionally, AGL-PE significantly improved survivability of common carp when challenged with koi herpes virus (KHV) due to immunostimulant effect of andrographolide (and chitosan in PE). Neutrophil left shift, a marker we used for establishing immunostimulant effect, was persistently high when either PE or andrographolide was introduced in diet; even maximum when they formed a hurdle system in AGL-PE diet. Modulation of Neutrophil left shift was possibly associated with amplified gut microbiota activity that coincided with higher fiber (and NFE) digestibility of AGL-PE group. The results firmly establish application of AGL-PE system as prebiotic additive in commercial aquafeed to simultaneously improve digestibility, feed utilization, growth, immunomodulatory and haematological properties in cultured fish.

Effects of fish meal replaced by methanotroph bacteria meal (Methylococcus capsulatus) on growth, body composition, antioxidant capacity, amino acids transporters and protein metabolism of turbot juveniles (Scophthalmus maximus L.)

Methanotroph bacteria meal (MBM) is produced by the fermentation of Methylococcus capsulatus, which use methane as carbon source. To evaluate the potential of replacing dietary fish meal (FM) with MBM, an eight-week growth trial was conducted on turbot juveniles (Scophthalmus maximus L.) with initial average weight of 9.13 ± 0.02 g. Seven isonitrogenous (crude protein, 51.00%) and isolipidic (crude lipid, 11.50%) diets were formulated by substituting FM protein with 0% (MBM0, the control diet), 15% (MBM15), 30% (MBM30), 45% (MBM45), 60% (MBM60), 80% (MBM80) and 100% (MBM100) MBM. Each diet was randomly assigned to triplicate fibreglass tanks (600 L). The survival rate (over 98%) was not significantly different among dietary treatments (P > 0.05). Also, no significant differences in specific growth rate (SGR), feed efficiency ratio (FER) and flesh yield (FY) were observed among fish fed with diets MBM0, MBM15 and MBM30, whereas these parameters were significantly reduced by further increase of dietary MBM (P < 0.05). Apparent digestibility coefficient (ADC) of nutrients was significantly liner reduced with increasing dietary MBM (P < 0.05). The body composition was altered by dietary MBM, as evidenced by an increase in carcass ash and muscle palmitic acid (C16:0) proportion, along with a decrease in n-3 polyunsaturated fatty acids (PUFA) proportion in muscle. The antioxidant capacity was not compromised until the replacement level reached 80%, characterized by a significant decrease in serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity and an increase in malondialdehyde (MDA) content. The liver health also tended to be compromised in fish fed with diets MBM80 and MBM100, evidenced by significantly increased glutamic oxalacetic transaminase (GOT) in serum and severe vacuolation of liver. The gene expression of intestinal amino acids transporters and hepatic general control nonderepressible 2 (gcn2) was first up-regulated and then down-regulated with significantly quadratic pattern (P < 0.05). Also, the expression of genes related to protein degradation in muscle, such as calpain small subunit 1-like (capns1-like), autophagy related 4B cysteine peptidase (atg4b) and cathepsin-d, exhibited a similar trend. While the gene expression of myogenic regulatory factors in muscle, such as follistatin, myogenin and myosin light chain (mlc), was significantly reduced in groups MBM80 and MBM100 as compared with the control (P < 0.05), which resembled the expression of mammalian target of rapamycin (mtor) in liver. Overall, MBM can replace up to 30% dietary FM without significantly adverse effects on growth performance and health of turbot juveniles, but excessive substitution levels (80% and 100%) would compromise antioxidant capacity, liver health and protein metabolism.

A Natural Gas Fermentation Bacterial Meal (FeedKind®) as a Functional Alternative Ingredient for Fishmeal in Diet of Largemouth Bass, Micropterus salmoides.

A 10-week growth study was conducted to evaluate the effect of a natural gas fermentation bacterial meal (FeedKind®, FK) as a fishmeal (FM) alternative in largemouth bass (Micropterus salmoides) (48.0 ± 0.03 g). Four isonitrogenous and isoenergetic diets were formulated including one commercial control (C, 42% FM) and three experimental diets with gradient FK of 3% (FK3, 29%FM), 6% (FK6, 26%FM) and 9% (FK9, 23%FM), respectively. FK-fed groups showed significantly higher SR than that of C group. The WGR and SGR of fish fed FK3 and FK6 were significantly higher than those of FK9, but not statistical different from the C group. FK-fed groups showed higher apparent digestibility coefficients of dry matter and nutrients. Further, FK-fed groups increased the ratio of SOD/MDA in the plasma and liver, and the upregulation of intestinal Keap1 and downregulation of HIF1α was found in FK3. Furthermore, FK-fed groups showed higher microbial richness and diversity. Pearson correlation analysis found that antioxidant relevant biomarkers were negatively correlated with the relative abundance of certain potential beneficial bacteria. In conclusion, supplemented up to 3–6% FK replacing FM in a low FM diet of largemouth bass could increase growth, survival rate, antioxidant capacity, and improve gut microbiota.

Anti-Nutritional Factors and Protein Dispersibility Index as Principal Quality Indicators for Soybean Meal in Diet of Nile Tilapia (Oreochromis niloticus GIFT), a Meta-Analysis.

Simple SummarySoybean meal is an effective protein source in aquafeeds and is characterized by high protein content, high digestibility, reasonable price, and stable supply. The quality of soybean meal varies with factors such as seed genotype, soil type, planting area, processing conditions, storage conditions, etc. Differences in soybean meal quality may lead to differences in the production performances of animals. For this reason, we investigated the nutrient composition, anti-nutritional factors and physicochemical properties of different soybean meals produced on the same production line with soybeans from different origins, and compared the effects of different soybean meals on the physiological characteristics of Nile tilapia (Oreochromis niloticus GIFT). This study identified key indicators that could distinguish the quality of soybean meals, and established a correlation model between quality indicators of soybean meal and the growth performance of Nile tilapia. These results are of great significance for evaluating the quality of soybean meals and promoting the efficient application of soybean meal in aquafeeds.Soybean meal (SBM) is the most important plant protein source in animal feed. This study investigated the characteristics of different SBMs, produced by soybeans from America and Brazil (SBM-A and SBM-B) in 2017–2021 under the same controlled conditions. The effects of different SBMs on the growth performance of Nile tilapia (Oreochromis niloticus, GIFT) and apparent digestibility coefficients (ADCs) of nutrients and energy were studied. The results showed that protein dispersibility index (PDI), urease activity (UA), glycinin and fiber were the four primary key indicators for distinguishing the characteristics of the tested SBMs. The meta-analysis results suggested that UA, glycinin, and fiber showed a negative effect on the survival rate (SR) and weight gain rate (WGR) of the Nile tilapia, whereas β-conglycinin, PDI, and nitrogen solubility index (NSI) had a positive effect on the SR and WGR of the fish. The ADCs of dry matter, the gross energy, phosphorus, crude protein, valine (Val), lysine (Lys), histidine (His), serine (Ser), and glutamate (Glu) of the Diet-A group (SBM-A inclusion) were significantly higher than those in the Diet-B group (SBM-B inclusion) (p < 0.05). However, no significant difference was found in ADCs of macro-nutrients between the two SBMs (p > 0.05). Overall, PDI, UA, glycinin, and fiber were the main indicators reflecting the characteristics of the tested SBMs, and UA, glycinin, β-conglycinin, and PDI had the greatest impact on the growth performance of Nile tilapia in this study. PDI was a more sensitive indicator than NSI for representing the protein quality of SBM.

Brown shrimp (Crangon crangon) processing remains as ingredient for Litopenaeus vannamei feeds: Biochemical characterisation and digestibility

Processing remains of brown shrimp, Crangon crangon, account for up to 60 % of the catch while only the small muscle fraction is used for human consumption. Incorporation into aquafeeds for high-valued species would reduce waste, create by-product value and promote sustainable aquaculture development. A detailed chemical characterisation of the remains from mechanically peeled brown shrimp was made and apparent nutrient digestibility coefficients in Litopenaeus vannamei were investigated. Brown shrimp processing remains (BSPR) contain substantial amounts of key nutrients (521 g⋅kg-1 crude protein, 74 g⋅kg-1 total lipid, 15 MJ⋅kg-1 gross energy) and valuable functional ingredients were detected (cholesterol, astaxanthin). Apparent energy (82 %) and protein (86 %) digestibility coefficients reveal good bioavailability of these nutrients. Dry matter digestibility was lower (64 %) presumably due to the high ash content (244 g⋅kg-1). The amino acid profile meets dietary requirements of penaeid shrimp with high apparent lysine and methionine digestibility coefficients. Analysis of macro- and micro minerals showed reasonable levels of required dietary minerals (phosphorus, magnesium, copper, manganese, selenium, zinc) and apparent copper digestibility was high (93 %). Contamination levels present in BSPR were below European standards acceptable for human consumption. Processing remains of brown shrimp have a high potential as alternative feed ingredient in sustainable diets for L. vannamei in recirculating aquaculture systems.

Oxidized Palm Oil Diet Affects Fatty Acid Profiles, Apparent Digestibility Coefficients and Liver of Hybrid Grouper Juvenile (Epinephelus fuscoguttatus × Epinephelus lanceolatus)

Vegetable oil is progressively replacing fish oil (FO) in aquafeed production. However, the effect of oxidized vegetable oil is less reported. This study was done to investigate the effects of oxidized refined palm oil (RPO) on the growth performance, feed utilization, proximate and fatty acid profiles, apparent digestibility coefficients and oxidative stress of hybrid grouper juvenile (Epinephelus fuscoguttatus × E. lanceolatus). RPO was force-oxidized and introduced into diets at three oxidative levels to replace 50% of FO. Diets with FO and fresh RPO were served as controls. The peroxide value of the oxidized diets was measured as 14.73, 24.50, and 36.10 meq/kg for diets OxL, OxM, and OxH, respectively. These diets were fed to triplicate groups of hybrid grouper (initial body weight 9.91 ± 0.01 g) for 8 weeks. There was no significant difference in terms of growth performance, survival, feed utilization, and whole-body protein proximate composition in all treatments (p &amp;gt; 0.05). However, different dietary treatments affected the body fatty acids profile and fish-fed OxM diet achieved the highest body weight gain without significant difference (p &amp;gt; 0.05). In terms of hepaticsomatic index (HSI), fish-fed OxH showed a significantly lower value compared to other treatments. Similarly, the lowest apparent digestibility coefficients (ADC) of nutrients were observed in fish fed OxH diet. The oxidized diets caused significant lower blood cholesterol and high-density lipoprotein cholesterol (HDL) (p &amp;lt; 0.05). The oxidative stress in the liver as indicated by the significantly higher thiobarbituric acid-reactive substance (TBARS) value in fish fed all the oxidized diets while no significant changes on the muscle TBARS values. In conclusion, the oxidized RPO diets significantly affected the liver, the nutrient digestibility, and the blood total cholesterol and HDL. Furthermore, hybrid grouper can tolerate up to 20 meq/kg of oxidized RPO in the diet without compromising the growth.