Plant Protein Diets Research Articles

Effect of L-Hyp supplementation on collagen muscle histology, gene expression, growth performance, body composition and fillet texture on big size European sea bass (Dicentrarchux labrax)

Hydroxyproline (L-Hyp) is amply present in fishmeal but limited in plant-protein sources. This study was conducted to evaluate the effects of supplementation with dietary L-Hyp on the distribution of collagen types in the muscle, and on the texture, survival rate, growth rate, feed utilization, body composition as well as the expression of the gene that encodes the pro-alpha2 chains of type I collagen (Col Iα2) of large European sea bass (initial body weight 609.21 ± 75.39 g) from high plant-protein diets. Four isoproteic (42 % crude protein) and isolipidic (20 % crude lipid) experimental diets were formulated adding 0.6 (HL diet), 1.2 (HM diet), and 2% (HH diet) L-Hyp, respectively. Three periods of feeding of 45, 99 and 143 days were studied. L-Hyp supplementation at 1.2 % and 2 % significantly improved specific growth rate (SGR) and feed conversion ratio (FCR). In the white muscle, type I, IV collagen and trichromic stain were significantly higher in HH feed than the control diet. In the red muscle, only type I collagen was higher. HH diet, also increases Col Iα2 mRNA levels in muscle significantly. It can be concluded that the addition of crystalline l-Hyp at 1.2 % or 2 % in high plant-protein diets indicates positive effects on growth performance of adult European sea bass and increase in muscle total collagen deposition.

Effects of enzymatic hydrolysis chicken by‐product in high plant‐based protein diet on growth performance, digestive capacity, antioxidant capacity and non‐specific immunity of juvenile turbot ( Scophthalmus maximus L.)

A 60-day feeding trial was conducted to investigate the effect of enzymatic hydrolysis chicken by-product (EHC) supplementation in high plant protein diets on growth performance, digestive capacity, antioxidant capacity and non-specific immunity of juvenile turbot (Scophthalmus maximus L.). The diet with 620 g/kg fish meal (FM) was used as the positive control group (FM group), while the diet with 372 g/kg FM and 256 g/kg degossypolled cottonseed protein were used as the negative control group (0 g/kg EHC group). Based on the negative control diet, grade levels of EHC (10, 20, 30 and 40 g/kg) were added, respectively. Results showed that fish fed with a high plant protein diet showed significantly lower growth performance, digestive capacity, antioxidant capacity and non-specific immunity than those of the positive control. The supplementation of 20 g/kg EHC significantly increased growth performance of fish as compared to the negative control. Furthermore, the digestive capacity of turbot fed the diet with 20 g/kg EHC was significantly improved by increasing activities of trypsin, pepsin and lipase and the expression of peptide transporter 1 (pept1). The antioxidant capacity and non-specific immunity of fish fed the diet with 20, 30 and 40 g/kg EHC were significantly improved by increasing activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (T-AOC), lysozyme (LZM) and acid phosphatase (ACP) in serum, decreasing the expression of interleukin-1β (il-1β) and tumour necrosis factor-α (tnf-α) and increasing the expression of transforming growth factor-β (tgf-β). In conclusion, the adverse effect of high plant protein diet on growth performance of turbot could be improved with the supplementation of 20 g/kg EHC, which could be due to the positive effect of EHC on digestive capacity, antioxidant capacity and non-specific immunity of juvenile turbot.

Tolerance assessment of dietary bile acids in common carp (Cyprinus carpio L.) fed a high plant protein diet

This study was conducted to investigate the tolerance dose of bile acids as a feed additive in high plant protein (PP) diets of common carp (Cyprinus carpio L.), by evaluating the responses in growth performance, hepatopancreas and intestinal histology, and glucose and lipid metabolism regulation. Three isonitrogenous and isoenergetic diets (36% PP and 10% fish meal) were prepared with bile acids supplementation of 0 (B0), 60 (B60), and 600 (B600) mg/kg, in which B600 was assayed as 10-fold the maximum recommended level (60 mg/kg) obtained by a previous efficacy test. Each diet was fed to six replicates of 30 common carps (initial body weight = 13.7 ± 0.01 g). Bile acids supplementation decreased feed conversion rate, hepatopancreas-somatic index, and hepatopancreas lipid content significantly. Dietary bile acids improved histopathological symptoms induced by the high PP diet, accompanied with down-regulated inflammatory responses (tnfα, il1β, il10, and tgfβ1) in distal intestine; and up-regulated anti-inflammatory cytokines (il10), but reduced apoptosis response (cleaved caspase3, detected by immunofluorescence staining) in the hepatopancreas. The ameliorated pathological symptoms and liver function in the B60 and B600 groups were closely related to the improved glucose metabolism regulation, with decreased fasting blood glucose and increased gluconeogenesis enzyme activity (G6Pase). Simultaneously, improved lipid metabolism was observed with up-regulated lipolysis (atgl) and bile acids synthesis (cyp7a1 and cyp8b1), but down-regulated cholesterol synthesis (hmgcr) gene-related mRNA, together with enhanced cholesterol transportation and bile acid recirculation to reduce lipid accumulation in the hepatopancreas. The phosphorylation of ERK1/2 was positively regulated by the systematic recovery of metabolic liver disease induced by the high PP diet. In conclusion, addition of 60 mg/kg bile acids is effective in common carp, with a 10-fold safety margin in commercial feed.

Dietary Plant Protein and Mortality Among Patients Receiving Maintenance Hemodialysis: A Cohort Study

Although greater dietary intake of protein has been associated with beneficial health effects among patients receiving maintenance hemodialysis (MHD), the effects of plant protein intake are less certain. We studied the association of the proportion of protein intake derived from plant sources with the risk of mortality among patients receiving MHD and explored factors that may modify these associations. Prospective observational cohort study. 1,119 Chinese hemodialysis patients aged over 18 years receiving MHD in 2014-2015. The proportion of plant protein intake to total protein intake. All-cause mortality and cardiovascular disease (CVD) mortality. Segmented regression models were fit to examine the association of plant protein intake proportion with the risk of all-cause mortality and CVD mortality. Multivariable-adjusted Cox proportional and cause-specific hazards models were used to estimate the hazard ratios (HR) and 95% CI for these outcomes. The means of plant protein intake normalized to ideal body weight and plant protein intake proportion were 0.6±0.2 (SD) g/kg per day and 0.538±0.134, respectively. During a median follow-up period of 28.0 months, 249 deaths occurred, with 146 of these deaths resulting from CVD. Overall, there was a U-shaped association between plant protein intake proportion and the risk of all-cause mortality, with an inflection point at 45%. Among patients with a plant protein intake proportion<45%, there was a 17% lower rate of mortality with each 5% greater plant protein intake proportion (HR, 0.83 [95% CI, 0.73-0.96]). Among patients with plant protein intake proportion≥45%, there was a 9% greater rate of mortality with each 5% greater plant protein intake proportion. A similar U-shaped association was observed for CVD mortality, with an inflection point at 44%. Observational study, potential unmeasured confounding. There was a U-shaped association between plant protein intake proportion and the risk of all-cause and cardiovascular mortality in MHD patients. If confirmed, these findings suggest a potential avenue to improve outcomes in this patient population.

The use of live food as a vehicle of soybean meal for nutritional programming of largemouth bass Micropterus salmoides

Nutritional Programming (NP) has been studied as a means of improving dietary plant protein (PP) utilization in different fish species. This study investigated the use of enriched live feed as a vehicle for NP in larval fish. The objective of this study was to determine the effect of NP induced during the larval stage via PP-enriched live feed on: (1) growth performance; (2) expression of genes associated with inflammation and any morphological changes in the intestine; and (3) muscle free amino acid composition in largemouth bass (Micropterus salmoides) during its later life stages. Two diets were used in this study, a fish meal (FM)-based diet, and a soybean mean (SBM)-based diet, serving as the PP diet. There were 4 groups in this study. The two control groups, ( +) Control and (−) Control, were not programmed and received the FM-diet and SBM-diet, respectively throughout the whole trial after the live feed stage (27–122 days post hatch (dph). The next group, programmed, was programmed with SBM-enriched Artemia nauplii during the live feed stage (4–26 dph) and challenged with the SBM-diet during the final stage of the study (79–122 dph). The final group, non-programmed, did not receive any programming and, was challenged with the SBM-diet during the final stage of the study. The programmed group experienced a significantly higher (%) weight gain during the PP-Challenge than the non-programmed group. In addition, the live feed programming resulted in significantly longer distal villi, and a higher villi length to width ratio, compared to the non-programmed group. No significant effects on free amino acid composition and gene expression were observed between the programmed and non-programmed group, except for an increased post-prandial concentration of free proline in the programmed group. The results of this study support use of live feed as a vehicle for nutritional programming and improving the growth performance of largemouth bass fed with a SBM-based diet.

Nutritional Programming with Dietary Soybean Meal and Its Effect on Gut Microbiota in Zebrafish (Danio rerio).

Nutritional programming (NP) is considered a promising approach that can counteract the negative effects of dietary plant protein (PP) by introducing PP to fish in the early developmental stages. Therefore the objective of our study was to assess the effect of NP on PP utilization and the gut microbiome in zebrafish Danio rerio. The study included four treatment groups: (1) a positive control group that received a fishmeal (FM) diet throughout the entire trial (+ control); (2) a negative control group that received PP diet throughout the entire trial (- control); (3) an NP group that received dietary PP during the larval stage followed by FM-based diet during the juvenile stage and PP diet again during a PP challenge in the grow-out phase (NP-PP); and (4) an FM-group that received FM-based diet during the larval and juvenile stages and was challenged with a PP diet during the grow-out phase (NP-FM). During the PP challenge, the NP-PP group achieved the highest weight gain compared to the (-) control and NP-FM groups. The relative abundance of certain phyla such as Chloroflexi, Planctomycetes, and Bacteroidetes presented higher values in some groups at early juvenile stage. The fish gut microbiome also presented differences throughout the study.

Physiological response of rainbow trout (Oncorhynchus mykiss) to graded levels of Hermetia illucens or poultry by-product meals as single or combined substitute ingredients to dietary plant proteins

In the last decades, processed animal proteins, such as poultry by-product meal (PBM) and insect meals have received great attention as sustainable and nutritious aquafeed ingredients. The aim of the present study was to evaluate growth performances, liver and gut histology, macromolecular composition and inflammatory response in rainbow trout (Oncorhynchus mykiss) fed diets deprived of fish meal, where graded levels of vegetable protein-rich ingredients, were replaced by defatted Hermetia illucens pupae meal (HM) or PBM, singly or in combination. To this end eight grossly iso‐proteic (45% DM), isolipidic (26% DM) and isoenergetic (23.5 MJ/kg DM) were offered each to triplicated groups of juveniles' fish in a 91 days feeding trial. A diet rich in vegetable protein derivatives high in soybean meal (CV) was prepared to have a 10:90 and 20:80 fish to vegetable protein and lipid ratios respectively. By contrast, a fish-based diet (CF) was formulated with opposite fish to vegetable protein and lipid ratios. Six more diets, were obtained by replacing graded levels of protein (10, 30 and 60%) of diet CV, by protein from a defatted Hermetia illucens pupae meal and/or poultry by-product meal, singly or combined, while maintaining the same vegetable to fish lipid ratio as in the CV diet.Relative to diets CV and CF, a medium to high substitution (30 and 60%) of dietary vegetable protein-rich ingredients, with HM and/or PBM resulted in improved growth performance as well as in a minor incidence of distal intestine morphological alterations. The diet including both the test animal proteins led to nearly the best overall response in terms of growth and gut/liver health. Both HM and PBM when included at moderate or high levels in the diet, resulted in a downregulation of the expression of inflammatory-related genes relative to diet CV. This effect was greater with HM than that observed with PBM and goes beyond the parallel reduction of vegetable protein and SBM levels in the same diets, suggesting a beneficial role of insect meal that warrant further investigation.The results obtained so far, provide support to a reliable use of alternative/underexploited protein and lipid sources [(HM) or (PBM)] in developing a new generation of sustainable and healthy trout diets that meet the circular economy principles.

Synergistic effects of Bacillus pumilus and exogenous protease on Nile tilapia (Oreochromis niloticus) growth, gut microbes, immune response and gene expression fed plant protein diet

The synergistic effects of probiotic (Bacillus pumilus) and/or exogenous enzyme (protease) on growth, immunity, serum parameters, gene expression and gut bacteria of Nile tilapia (3.62 ± 0.06 g) were investigated. Plant protein-based diets were formulated as the control diet, probiotic (pro, 1.85 × 105B. pumilus CFU kg−1), protease enzyme (enzy, 0.5 g protease kg −1), and their mixture of 1.85 × 105B. pumilus CFU kg−1 + 0.5 g protease kg −1 (pro-enzy), respectively. After 84 days, the results revealed that fish fed pro-enzy diet resulted in better (P < 0.05) growth performance and feed utilization, including highest goblet cells, thickness of musclaris, mucosal folds and enterocytes. In addition, the highest values of hematocrit (Htc), hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs), immunoglobulin M (IgM), lysozyme and phagocytic and serum parameters, including albumin, globulin and total protein were detected in the pro-enzy treatment (P < 0.05). The best levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were found in group fed pro-enzy diet. The highest relative levels of growth hormone (GH) were recorded in brain and liver of fish fed the control diet, while, insulin like growth factor (IGF-I) was higher in fish fed pro-enzy diet. Culture-independent molecular analyses of 16S ribosomal ribonucleic acid (16S rRNA) gene of gut bacteria showed that treatments directed intestinal bacteria towards health of fish, through inhibition of the growth of some hydrocarbon-degrading bacteria, such as Pseudomonas indica, and pathogenic bacteria, such as Citrobacter koseri. There were four genotypes, which homologized with mostly gas-fixating bacteria, were not affected by treatments, suggesting core gut bacteria. In conclusion, the addition of pro-enzy improved the growth performance, intestinal histological morphometric, immune response, hematological, biochemical blood, metabolic gene expression and intestinal bacterial flora of Nile tilapia fed diet free fish meal.

Associations between Dietary Animal and Plant Protein Intake and Cardiometabolic Risk Factors-A Cross-Sectional Study in China Health and Nutrition Survey.

Available data investigating the associations between dietary animal and plant protein intakes and cardiometabolic risk factors (CMRFs) among populations with habitual plant-based diets are heterogenous and limited in scope. The current study was to assess the associations between dietary animal and plant protein intakes and CMRFs, including lipid and lipoprotein profiles, glucose homeostasis biomarkers, low-grade chronic inflammatory biomarker and uric acid in Chinese adults. Data of 7886 apparently healthy adults were extracted from the China Health and Nutrition Survey 2009. Dietary protein (total, animal and plant) intakes were assessed with three consecutive 24 h dietary recalls, and CMRFs were measured with standard laboratory methods. Substituting 5% of energy intake from animal protein for carbohydrates was positively associated with total cholesterol, low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) and uric acid (all p < 0.05). Substituting 5% of energy intake from plant protein for carbohydrates was inversely associated with non-HDL-C and LDL-C:HDL-C ratio, and positively associated with HDL-C and glycated hemoglobin (all p < 0.05). Some of these associations varied in subgroup analyses by BMI, sex, age or region. There were no significant associations between animal or plant protein intakes and high-sensitivity C-reactive protein. The public health implication of these findings requires further investigation.

Growth and health status of the red claw crayfish, cherax quadricarinatus , fed diets with four typical plant protein sources as a replacement for fish meal

Four isonitrogenous (350 g/kg protein) diets were formulated for juvenile red claw crayfish, Cherax quadricarinatus, with half of the dietary fish meal replaced by four commonly used plant protein sources (cottonseed meal, soybean meal, rapeseed meal and peanut meal). A diet without fish meal replacement was used as a control. An eight-week growth trial was conducted to evaluate the growth and health of crayfish juveniles (6.71 ± 0.08 g) fed diets containing the five different protein sources. The weight gain and specific growth rate significantly decreased in the crayfish fed the peanut meal diet compared with those fed the control diet. Survival, hepatosomatic index and whole-body proximate compositions were not significantly influenced by different dietary plant protein sources. Intestinal damage is accompanied by higher activities of glutathione peroxidase, alanine aminotransferase and aspartate aminotransferase, and decreased lipase activities were observed in the crayfish fed the peanut meal diet. Crayfish fed the rapeseed diet also showed the detached peritrophic membrane and the lower lipase activities than those in control. Moreover, the malondialdehyde content increased and acid phosphatase activity decreased in the haemolymph of crayfish fed the soybean meal diet compared with those fed the control diet. Compared with those fed the control diet, the significantly increased valine contents, the activities of alkaline phosphatase and amylase were found in the crayfish fed the cottonseed meal diet. All these results suggest that soybean meal, rapeseed meal and peanut meal were not suitable substitute sources of plant protein for fish meal because of their adverse influences. On the contrary, cottonseed meal can be a good choice for fish meal replacement in the diet of juvenile Cherax quadricarinatus, as it does not have adverse effects on growth and could even increase amino acid nutrition, immunity and digestion.

Crude Protein Requirements Of Egg-type Baby Chicks Under Nigerian (Tropical) Environment

TWO feeding trials were conducted with day old mixed sexes of Apollo (White Leghorn) strain. The first experiment was designed to test the effectiveness of all — vegetable protein diets to meet the requirements of baby chicks. While the second one was designed to find out whether synthetic methionine and/or fishmeal supplementation are desirable in low quality protein of groundnut cake. Results showed that a diet based on plant proteins only, namely, those of groundnut cake and maize, is capable of stimulating rapid growth in chicks. Diets containing 24% all-vegetable protein, 22% plant protein plus 0.35% feed grade methionine or 20% plant protein containing 3% of fishmeal plus 0.37% feed grade methionine, satisfied the requirements for rapid growth and efficient feed utilization in young chicks. However, based on the prevailing prices of the ingredients used in formulating the rations, the results indicate that ration based on 24%of all — plant protein diet was least expensive.

PERFORMANCE OF BROILERS GIVEN DIFFERENT DIETARY LEVELS OF ACACIA SIEBERIANA DC. VAR. SIEBERIANA SEEDS

The study was aimed at evaluating the seeds of a leguminous plant, Acacia sieberiana DC as an alternative source of dietary plant protein for broilers. Five experimental diets containing 0 (control), 5, 10, 15 and 20% Acacia sieberiana seeds (ASS) were formulated and fed to 5 groups of birds during starter (0 - 4 weeks), grower (5 - 8 weeks) and finisher (9-12 weeks) periods respectively. There were 3 replicates per treatment, with 10 birds per replicate. At the end of the experiment, average weekly liveweight gains of 128.90 ±24.17, 122.68±25.09, 112.79 ± 22.83, 96.40 ± 21.53 and 99.56 + 21.53g were obtained for the birds on 0, 5, 10 and 20% ASS inclusion respectively. The average weekly feed consumption values were 413.47 ± 63.63, 408.59 ± 63.82, 304.60 ± 61.70, 347.96 ± 58.0 and 352.83 ± 59.76g for the birds on 0, 5, 10, 15 and 20% ASS respectively. The feed efficiencies were 0.289 ± 0.03, 0.272± 0.03, 0.264 + 0.03, 0.248 ± 0.03 and 0.253 ± 0.03 for the birds on 0. 5. 10. 15 and 20% ASS respectively. The data revealed that in general, the birds on 0, 5 and 10% ASS inclusion performed better (PÇ&lt;.05) than birds on 15 or 20% ASS. Results of carcass evaluation show that the gizzard, lungs and heads of the control birds had significantly (PÇ&lt;.05) higher weights than those of birds on 15 and 20% ASS. From these results it can be concluded that up to 10% ASS could be incorporated into poultry diet without deleterious effect on broilers.

Growth Performance of African Giant Land Snail Archachatina Marginata Fed Varying Dietary Protein Levels of Plant Source

The effects of isocaloric plant protein diets on the growth performance of African giant land snail Archachatina marginata were investigated for 28 weeks. A total of 120 juvenile A. marginata snails were used. Ten snails were randomly assigned to each of the four experimental diets containing 12%, 14%, 16%, and 18% crude protein from plant source respectively. Each diet constitutes a treatment and each treatment was replicated three times with 10 snails per replicate. Data on growth parameters were collected bi-weekly. Results showed that the performance of snails fed was significantly (p&lt;0.05) influenced by levels of dietary protein. The snail fed with 16% level of crude protein had the highest final somatic body weight (42.6g) and the superior feed conversion ratio (2.35) while beyond 16% level of crude protein the growth response declined. It was evident from this study that A. marginata snails fed 16% crude protein of plant source were the best in growth performance and that snails could be raised on diets comprising of crude protein exclusively from plant source.

Saccharomyces cerevisiae extracts improved the effects of a low fishmeal, complex plant protein diet in the orange-spotted grouper, Epinephelus coioides

Six iso-nitrogenous and iso-lipidic experimental diets were formulated to evaluate the effects of Saccharomyces cerevisiae extracts, as part of a low fishmeal diet with a complex plant protein source, on the orange-spotted grouper (Epinephelus coioides). In positive control group, fishmeal was the only protein source (FM). The negative control group (Y0) was fed low amounts of fishmeal, and plant protein was used as the protein source. The other diets were supplemented with Saccharomyces cerevisiae extract: 1 g/kg (Y1), 2 g/kg (Y2), 5 g/kg (Y5), and 10 g/kg (Y10). The Epinephelus coioides were divided into six groups, with three replicates per group and 30 groupers per replicate. The experiment lasted for 56 days. The results showed that there was no significant difference in weight gain rate and specific growth rate of FM, Y0 and Y2 groups (P > 0.05). In foregut, mucosal folds length in Y2 group was significantly greater than that in Y0, Y1 and Y10 groups (P < 0.05). The muscle thicknesses of foregut in Y2 and Y5 groups were significantly higher than those in other groups (P < 0.05). The muscle thicknesses of midgut and hindgut in Y2 group were significantly higher than those in Y0 group (P < 0.05). IL-1β and TNF-α in Y1 group were significantly downregulated compared with Y0 group (P < 0.05). After Vibrio harveyi challenge, survival rate in Y1 and Y10 groups was significantly greater than that in Y0 group (P < 0.05). These results indicated that compared with the negative control group, the addition of 2 g/kg S. cerevisiae extract could increase the mucosal folds length of the foregut, and the muscle thickness of the entire intestine, and maintain the growth similar to that of the positive control group. Adding S. cerevisiae extract to feed may improve the immune capacity of E. coioides, but the improvement was not obvious under the challenge of V. harveyi.

Effects of fishmeal replacement with composite mixture of shrimp hydrolysate and plant proteins on growth performance, feed utilization, and target of rapamycin pathway in largemouth bass, Micropterus salmoides

An 82 days' feeding trial was conducted to investigate the potentiality of fishmeal replacement with the composite mixture of shrimp hydrolysate and plant proteins in diets for largemouth bass. Triplicate groups of fish were fed the experimental diets with 45 (FM45, the control), 40 (FM40), 35 (FM35), 30 (FM30) and 25% (FM25) fishmeal twice daily. Results showed that the mixture of protein sources can reduce the use of fishmeal to 30% with obvious improvement of growth performance, whereas higher substitution level (FM25 group) inhibited growth slightly compared to the control group. The fishmeal replacement supported significantly higher apparent digestibility coefficients (ADC) of protein and amino acids compared to the control, which may be partly involved in the activation of amino acid-sensing target of rapamycin (TOR) pathway. Consistently, the replacement of fishmeal elevated the expression of TOR and ribosomal protein S6, but significantly decreased the expression of eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), and this confirmed the activation of TOR pathway induced by the fishmeal replacement in the present study. In summary, appropriate fishmeal replacement with composite mixture of shrimp hydrolysate and plant proteins can activate the TOR pathway and improve the growth performance of largemouth bass, and fishmeal content in the diets for largemouth bass can be reduced to 30% with the compound proteins.

Intestinal Explant Cultures from Gilthead Seabream (Sparus aurata, L.) Allowed the Determination of Mucosal Sensitivity to Bacterial Pathogens and the Impact of a Plant Protein Diet.

The interaction between diet and intestinal health has been widely discussed, although in vivo approaches have reported limitations. The intestine explant culture system developed provides an advantage since it reduces the number of experimental fish and increases the time of incubation compared to similar methods, becoming a valuable tool in the study of the interactions between pathogenic bacteria, rearing conditions, or dietary components and fish gut immune response. The objective of this study was to determine the influence of the total substitution of fish meal by plants on the immune intestinal status of seabream using an ex vivo bacterial challenge. For this aim, two growth stages of fish were assayed (12 g): phase I (90 days), up to 68 g, and phase II (305 days), up to 250 g. Additionally, in phase II, the effects of long term and short term exposure (15 days) to a plant protein (PP) diet were determined. PP diet altered the mucosal immune homeostasis, the younger fish being more sensitive, and the intestine from fish fed short-term plant diets showed a higher immune response than with long-term feeding. Vibrio alginolyticus (V. alginolyticus) triggered the highest immune and inflammatory response, while COX-2 expression was significantly induced by Photobacterium damselae subsp. Piscicida (P. damselae subsp. Piscicida), showing a positive high correlation between the pro-inflammatory genes encoding interleukin 1β (IL1-β), interleukin 6 (IL-6) and cyclooxygenase 2(COX-2).

Mannanoligosaccharides as a Carbon Source in Biofloc Boost Dietary Plant Protein and Water Quality, Growth, Immunity and Aeromonas hydrophila Resistance in Nile Tilapia (Oreochromis niloticus).

The aim of the present study was to evaluate mannan oligosaccharides (MOS) or glycerol (GLY) as a carbon source on biofloc systems of Nile tilapia (O. niloticus) juveniles. Fish (n = 750) were reared in open flow (Controls) or biofloc systems (B-GLY and B-MOS) fed with a plant or fish protein source over a period of twelve weeks. Total ammonia nitrogen and nitrate decreased in the biofloc groups, while biofloc volume increased in B-MOS. Compared to the controls, B-MOS and B-GLY exhibited higher weight gain and improved feed conversion, irrespectively of the diet. Serum level of C-reactive protein was reduced, while IgM and lysozyme activity was higher in the B-MOS fish, compared to other groups. Intestinal Bacillus spp. count was increased, whereas Vibrio, Aeromonas and Pseudomonas spp. counts decreased in B-MOS reared groups, compared to the other groups. The proinflammatory cytokine (IL-8 and IFN-γ) transcript expression was upregulated in B-MOS more than B-GLY reared groups. Compared to the controls, the virulence of Aeromonas hydrophila was decreased in the B-MOS and B-GLY groups. The results indicate several benefits of using MOS as a carbon source in a biofloc Nile tilapia system; a cost benefit analysis is required to assess the economic viability of this.

Effect of torula yeast on growth performance, diarrhea incidence, and blood characteristics in weanling pigs

Two experiments were conducted to test the hypothesis that torula yeast may replace animal and plant proteins in diets for weanling pigs without negatively impacting growth performance or blood characteristics. In exp. 1, 128 weanling pigs (6.71 ± 0.76 kg) were allotted to four treatments with four pigs per pen and eight replicate pens per diet. Pigs were fed one of four diets from day 1 to 14 post-weaning (phase 1), whereas all pigs were fed a common diet in phase 2 (day 15 to 28). The four dietary treatments included a control diet with 5% fish meal, 2.5% plasma protein, and no torula yeast. The second diet contained 5% fish meal, 4.75% torula yeast, and no plasma protein. The third diet contained 2.5% plasma protein, 6% torula yeast, and no fish meal, and the last diet contained 10.75% torula yeast, no fish meal, and no plasma protein. The inclusion of torula yeast was calculated to replace the amount of digestible Lys provided by fish meal, plasma protein, or both fish meal and plasma protein in the control diet. During the initial 14 d, fecal scores were visually assessed. At the end of phase 1, blood samples were collected and tumor necrosis factor-α (TNF-α), blood urea nitrogen (BUN), peptide YY, immunoglobulin G, total protein, and albumin were analyzed. Results indicated that torula yeast could replace fish meal and plasma protein without affecting growth performance, fecal scores, or blood characteristics of pigs. In exp. 2, 160 weanling pigs (6.11 ± 0.62 kg) were allotted to one of four diets with five pigs per pen and eight replicate pens per diet. Phase 1 diets contained 0%, 10%, 18%, or 26% torula yeast, whereas phase 2 diets contained 0%, 8%, 14%, or 20% torula yeast. Torula yeast was included in diets at the expense of animal proteins and soybean meal. On days 14 and 28, blood samples were collected and concentrations of cytokines, BUN, total protein, and albumin were analyzed. Phase 2 gain-to-feed ratio (G:F) linearly increased (P < 0.01) as the concentration of torula yeast increased in the diets. The concentration of albumin on day 14 linearly increased (P < 0.05) and the concentration of TNF-α was linearly reduced (P < 0.01) as the concentration of torula yeast increased in the diets. In conclusion, under the conditions of this research, torula yeast could replace fish meal and plasma protein without affecting the growth performance of pigs, but inclusion of increasing levels of torula yeast improved G:F of pigs, which may be because of greater nutrient utilization.

On-farm evaluation of dietary animal and plant proteins to replace fishmeal in sub-adult olive flounder Paralichthys olivaceus

BackgroundHigh demand and low supply of fishmeal due to overexploitation of fisheries resources have resulted in a dramatic increase in the price of this ingredient. Olive flounder (Paralichthys olivaceus) commercial feed contains approximately 60% fishmeal and limited success has been achieved in identifying sustainable alternative protein sources for this species.MethodsAn on-farm feeding trial was conducted to compare a basal diet containing 65% as the control (CONT) with two experimental diets replacing 10% of fishmeal by animal protein (AP10) or 20% of fishmeal by animal and plant protein (APP20). Sub-adult olive flounder averaging 327 ± 9.3 g (mean±SD) were fed one of the three diets in triplicate groups for 16 weeks.ResultsWeight gain, specific growth rate, feed efficiency, protein efficiency ratio, and survival were not significantly different among fish fed all the experimental diets (P > 0.05). Also, non-specific immune responses (superoxide dismutase and lysozyme activity), serum biochemical parameters, and intestinal villi length were not significantly different among fish fed all the experimental diets (P > 0.05).ConclusionsTherefore, based on growth performance, non-specific immune responses, serum biochemical parameters, and intestinal histology, dietary animal and plant protein mixtures could replace up to 20% of fishmeal in the diet of sub-adult olive flounder.

Plant protein diet-induced hypoimmunity by affecting the spiral valve intestinal microbiota and bile acid enterohepatic circulation in Amur sturgeon (Acipenser schrenckii)

An 8-week growth trial was conducted to study enterohepatic recirculation of bile acid metabolism and the intestinal microbiota of Amur sturgeon (Acipenser schrenckii) fed with three diets, including 540 g/kg, 270 g/kg or 0 g/kg fishmeal, which was correspondingly replaced by a plant protein blend (named P0, P50 and P100, respectively). The diets were designed to be isonitrogenous, isoenergetic and essential nutrients balanced. With rising levels of dietary plant protein, disruption of the spiral valve intestinal microbiota and more morbidity with liver disease were observed in the P100 group, although there were no haematological abnormalities observed. An obvious bile acids enterohepatic circulation disorder was found with phenotypes of increased liver bile acids compensatory synthesis, and reduced expression of bile acid receptors (FXR and TGR5), which induced BA accumulative toxicity. Accompanied by increased oxidative stress, it further induced hepatic lesions and hypoimmunity, which were non-negligible reasons for the high mortality and low utilization ability of plant protein by Amur sturgeon.