POET CFP, a corn‐fermented protein concentrate, as a potential novel aquafeed ingredient for juvenile European sea bass, Dicentrarchus labrax

This study was designed to determine the effect of complete substitution of fish meal (FM) by three plant protein sources including extruded soybean meal (SBM), extruded full-fat soybean (FFSB) and corn gluten meal (CGM) on growth and feed utilization of Nile tilapia Oreochromis niloticus and tilapia galilae Sarothrodon galilaeus. Four isonitrogenous of crude protein (ca. 28.0%) and isocaloric (ca. 19 MJ kg−1) experimental diets were formulated. The control diet (diet 1) was prepared with FM as the main protein sources. Diets 2–4, each FM control diet, were completely substituted with SBM (diet 2), FFSB (diet 3) and CGM (diet 4). l-lysine and dl-methionine were added to plant protein diets to cover the nutritional requirements of tilapia. Each treatment was allocated to three net pens and fed for 17 weeks. Nile tilapia fed the control diet showed significantly higher (P≤0.05) values for final body weight (FBW), feed intake (FI), weight gain (WG) and specific growth rate (SGR), whereas fish fed the diet with CGM achieved the lowest values. Tilapia galilae fed SBM diet recorded the highest (P≤0.05) values for growth performance. Better feed conversion ratio (FCR) for both Oreochromis niloticus and Sarothrodon galilaeus was observed when fish were fed SBM diet, whereas the worse FCR was recorded for FFSB diet. Feed utilization parameters including protein productive value (PPV), fat retention (FR) and energy retention (ER) showed significant differences (P≤0.05) for both the species fed different dietary protein sources. The present results suggest that, for Nile tilapia, both SBM and FFSB supplemented with dl-methionine and l-lysine can completely replace dietary FM. Meanwhile, S. galilaeus fed SBM diet exhibited comparable growth and feed utilization with those fish fed a fish-meal-based diet.

Dietary oleic acid supplementation improves feed efficiency and modulates fatty acid profile and cell signaling pathway in European sea bass (Dicentrarchus labrax) juveniles fed high-lipid diets

Simple SummaryThe rapid growth of the world’s population has increased the demand for seafood, leading to the expansion of aquaculture to fulfill these needs and reduce the pressure on wild fish stocks. Plant feedstuffs (PFs) are often used as the main protein source in aquafeeds due to their wide availability and low cost. However, PFs usually contain high levels of non-starch polysaccharides that limit their utilization in aquafeeds, mainly for carnivorous fish. Solid-state fermentation (SSF) is a cost-effective technological process that may reduce anti-nutritional factor levels while improving nutrient digestibility and the production of several bioactive compounds, enhancing feedstuffs’ nutritional value in aquafeeds. Hence, this study evaluated the effects of using a PF mixture (rapeseed, soybean, rice bran, and sunflower seed meals, 25% each) solid-state fermented (SSFed) with Aspergillus niger CECT 2088 at two inclusion levels (20% and 40%) on European sea bass juveniles’ growth performance, feed digestibility, digestive and catabolic enzyme activity, and plasma metabolites. Overall, the SSFed PF mixture improved the overall feed digestibility, and utilization efficiency, when included at balanced level (20%) without negatively impacting fish growth performance, but not at the higher level (40%).This study aimed to evaluate the utilization by juvenile European sea bass of a SSFed PF mixture with Aspergillus niger CECT 2088. A 22-day digestibility and a 50-day growth trial were performed testing four diets, including 20 or 40% of an unfermented or SSFed PF mixture (rapeseed, soybean, rice bran, and sunflower seed meals, 25% each). SSF of the PF added cellulase and β-glucosidase activity to the diets. Mycotoxin contamination was not detected in any of the experimental diets except for residual levels of zearalenone and deoxynivalenol (100 and 600 times lower than that established by the European Commission Recommendation-2006/576/EC). In diets including 20% PF, SSF did not affect growth but increased apparent digestibility coefficients of protein and energy, feed efficiency, and protein efficiency ratio. On the contrary, in diets including 40% PF, SSF decreased growth performance, feed intake, feed and protein efficiency, and diet digestibility. SSF decreased the intestinal amylase activity in the 40% SSFed diet, while total alkaline proteases decreased in the 20% and 40% SSFed diets. Hepatic amino acid catabolic enzyme activity was not modulated by SSF, and plasma total protein, cholesterol, and triglyceride levels were similar among dietary treatments. In conclusion, dietary inclusion of moderate levels of the SSFed PF, up to 20%, improves the overall feed utilization efficiency without negatively impacting European sea bass growth performance. The replacement of PF with the SSFed PF mixture may contribute to reducing the environmental footprint of aquaculture production.

Five crossbred beef steers (329 kg) were used in a 5 x 5 Latin square experiment with 14-d periods to determine the effects of supplementation with high-nitrogen (N) feeds alone or mixed with tallow on sites of digestion with a basal diet of bermudagrass hay. Hay was 1.93% nitrogen, 75% neutral detergent fibre and fed at 1.83% of body weight (dry matter; DM). Supplements were basal (B; 105 g DM): 81.8% dried molasses product (DMP) and 18.2% calcium carbonate (CC); soybean meal (S; 942 g DM): 88.0% soybean meal, 9.8% DMP and 2.2% CC; S mixed with 9.8% tallow (SF; 1041 g DM); corn gluten and blood meals (CB; 662 g DM): 62.5% corn gluten meal, 20.8% blood meal, 13.6% DMP and 3.0% CC; CB mixed with 13.2% tallow (CBF; 757 g DM). Total N intake was 117, 185, 187, 174 and 172 g/d, and duodenal N flow was 121, 148, 143, 162 and 169 g/d for B, S, SF, CB and CBF, respectively, being lower for B than for other treatments and higher for supplements with the corn gluten and blood meal mix than for soybean meal (P less than 0.05). Duodenal microbial N flow was 39, 51, 49, 38 and 45 g/d for B, S, SF, CB and CBF, respectively, being greater (P less than 0.05) for supplements with soybean meal than with corn gluten and blood meals. Duodenal flow of feed N was greater (P less than 0.05) with than without high-N feeds and for supplemental corn gluten and blood meals than for soybean meal (78, 90, 86, 117 and 116 g/d for B, S, SF, CB and CBF, respectively). In conclusion, mixing of tallow and high-N feeds did not affect the extent of ruminal N disappearance, and soybean meal supplementation increased duodenal N flow less than did supplementation with corn gluten and blood meals. Increased duodenal N flow with soybean meal was associated with about equal elevations of ruminal outflow of microbial and feed N, whereas the corn gluten-blood meal mix affected the intestinal protein supply by increasing ruminal escape of feed protein.

Effect of dietary lipid level on growth performance and feed utilization by European sea bass juveniles ( Dicentrarchus labrax)

Lauric acid (LA), a medium-chain fatty acid (C12), can promote growth performance and decrease oxidative damage and lipid deposition in animals. This study aimed to evaluate the effect of dietary supplementation of lauric acid as a functional ingredient on European seabass juveniles’ growth performance and intestine antioxidant and immunological status. For this purpose, four practical diets were formulated to be isoproteic and isolipidic, including 0, 0.5, 1, and 2% of LA, and fed to triplicate groups of European seabass juveniles (~12.7 g) for 61 days. Dietary LA supplementation did not affect growth performance, feed utilization, or whole-body composition, but feed intake increased at a concentration-dependent level. However, the plasmatic triglyceride content was increased at the higher level of LA supplementation. In the intestine, catalase and glutathione reductase activities and lipid peroxidation levels were lower in fish fed the 1% LA diet than in the control group. The hepatic LPO level was higher in fish fed 0.5% LA than in the control group. Fish fed the 1% LA diet presented lower intestinal expressions of caspase 3, tumor necrosis factor-alpha, interleukins 10, 6, and 1-β, and a lower plasma white blood cell number. Overall, up to 2% dietary supplementation of lauric acid as a functional ingredient showed a trend to improve European sea bass juveniles’ growth performance without affecting feed utilization. Moreover, 1% dietary inclusion of LA reduced intestinal lipid peroxidation and downregulated pro-inflammatory and anti-inflammatory genes, thus enhancing the intestine’s homeostatic status.

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 short-chain fatty acid supplementation does not affect growth performance, metabolism, and oxidative status of European seabass (Dicentrarchus labrax) juveniles.

Effects of soybean meal fermentation by Lactobacillus plantarum P8 on growth, immune responses, and intestinal morphology in juvenile turbot (Scophthalmus maximus L.)

Corn gluten meal (CGM), pea protein isolate (PPI) and their mixture (CPP, 1:1 ratio) were evaluated as fishmeal (FM) alternatives in black sea bream (Acanthopagrus schlegelii) juveniles (9.02 ± 0.12 g). A FM diet was designed as control, and other six diets had 20% and 40% FM protein replaced by CGM, PPI and CPP, respectively, with the supplementation of crystalline methionine, arginine and lysine. After the 8-week feeding trial, significantly lower weight gain was found in fish fed the 40% CGM diet (p < .05), whereas other treatments had no statistical difference (p > .05). The values of feed efficiency ratio and feed intake, as well as proximate compositions of muscle and whole body, were not significantly influenced in all treatments. Apparent digestibility coefficients (ADCs) of dry matter, crude protein, threonine, valine, methionine, isoleucine, leucine, phenylalanine and lysine were significantly influenced by protein source. Fish fed the 40% CGM diet had significantly higher content of essential amino acid in muscle than that of the 20% PPI diet. Fish fed the 40% CGM diet had significantly lower content of serum cholesterol than other treatments (p < .05). Elevated serum superoxide dismutase activity was found in fish fed the 40% plant protein diets. In conclusion, between 20% and 40% FM protein could be replaced by CGM, while about 40% FM protein derived from PPI and CPP could be applied in black sea bream.

Effects of the partial substitution of dietary fish meal by differently processed soybean meals on growth performance, nutrient digestibility and activity of intestinal brush border enzymes in the European sea bass ( Dicentrarchus labrax)

Apparent digestibility of protein, energy and amino acids in nine protein sources at two content levels for mandarin fish, Siniperca chuatsi

The present trials aimed to investigate the effects of replacing fish meal with plant proteins in diets for cod, using a regression design where fish meal constituted the control. The plant protein diets were formulated to meet the amino acid requirements according to NRC (1993) and contained corn gluten meal, soybean meal, a mixture of these, or a mixture of wheat gluten meal and soybean concentrate. The plant protein fraction constituted up to 440 g kg )1 of the extruded diet. Two feeding experiments were conducted, one at high (11 � C) and one at low (6.5 � C) temperature. High growth and feed utilization were obtained in all diet groups at both temperatures. However, only in Exp.1 (11 � C), growth and feed utilization were linearly reduced by increases in dietary soybean and corn gluten meal, while no such effect was detected in Exp.2 (6.5 � C). Reductions in protein retention were seen at both temperatures with use of all evaluated plant protein sources. Due to large amounts of plant protein ingredients in diet, differences in diet amino acid composition were seen. These were partly reflected in the muscle free amino acid pool. Dietary plant ingredients did not affect whole body, liver or muscle proximate compositions, or liver indices. In both experiments, blood parameters were within the range of earlier reported normal values and indicated, together with low mortality, good fish health status. The results show that there is high potential to use protein-rich plant ingredients in diets for Atlantic cod.

Comparison of dehulled, fermented and enzyme-treated soybean meal in diets for largemouth bass, Micropterus salmoides: Effects on growth performance, feed utilization, immune response and intestinal morphology

Use of defatted soybean meal as a substitute for fish meal in diets of Japanese flounder ( Paralichthys olivaceus)