Impact of early-life rearing history on gut microbiome succession and performance of Nile tilapia

Background Fish gut microbial colonisation starts during larval stage and plays an important role in host’s growth and health. To what extent first colonisation could influence the gut microbiome succession and growth in later life remains unknown. In this study, Nile tilapia embryos were incubated in two different environments, a flow-through system (FTS) and a biofloc system (BFS); hatched larvae were subsequently cultured in the systems for 14 days of feeding (dof). Fish were then transferred to one common recirculating aquaculture system (RAS1, common garden, 15–62 dof), followed by a growth trial in another RAS (RAS2, growth trial, 63–105 dof). In RAS2, fish were fed with two types of diet, differing in non-starch polysaccharide content. Our aim was to test the effect of rearing environment on the gut microbiome development, nutrient digestibility and growth performance of Nile tilapia during post-larvae stages. Results Larvae cultured in the BFS showed better growth and different gut microbiome, compared to FTS. After the common garden, the gut microbiome still showed differences in species composition, while body weight was similar. Long-term effects of early life rearing history on fish gut microbiome composition, nutrient digestibility, nitrogen and energy balances were not observed. Still, BFS-reared fish had more gut microbial interactions than FTS-reared fish. A temporal effect was observed in gut microbiome succession during fish development, although a distinct number of core microbiome remained present throughout the experimental period. Conclusion Our results indicated that the legacy effect of first microbial colonisation of the fish gut gradually disappeared during host development, with no differences in gut microbiome composition and growth performance observed in later life after culture in a common environment. However, early life exposure of larvae to biofloc consistently increased the microbial interactions in the gut of juvenile Nile tilapia and might possibly benefit gut health.

Effects of a Single Cell Protein (Methylococcus capsulatus, Bath) in Pacific White Shrimp (Penaeus vannamei) Diet on Growth Performance, Survival Rate and Resistance to Vibrio parahaemolyticus, the Causative Agent of Acute Hepatopancreatic Necrosis Disease

The efficacy of a single cell protein (SCP) methanotroph (Methylococcus capsulatus, Bath) bacteria meal (FeedKind®, Calysta, Menlo Park, CA, United States), in Pacific white shrimp (Penaeus vannamei) diets was studied to determine growth performance, survival rate and disease resistance against Vibrio parahaemolyticus causing Acute Hepatopancreatic Necrosis Disease (AHPND). The growth trial was assigned in a completely randomized design (CRD) with four treatments and 5 replicates of each, T1: a fishmeal-based control containing 15% fish meal and 3 diets with graded levels of methanotroph bacteria meal, namely T2: 5% methanotroph bacteria meal, T3: 10% methanotroph bacteria meal, and T4: 15% methanotroph bacteria meal. Shrimp were fed ad libitum for 6 weeks on trial diets to assess growth. Subsequent to the growth trial, three replicates of the same groups were exposed to V. parahaemolyticus by a single bath challenge and held for a further 15 days on the same diets as the growth study to assess survival and resistance. No significant differences (p > 0.05) in survival or in growth performance, including final weight, weight gain, specific growth rate, feed consumption or feed conversion ratio of white shrimp fed feeds containing methanotroph bacteria meal or control diets for 6 weeks. Immune markers such as hemocyte counts, phenoloxidase, superoxide dismutase and lysozyme activity were similar across all groups after the 6-week feeding trial. In a V. parahaemolyticus challenge, methanotroph bacteria meal in the diet significantly promoted the survival rate, and the reduction of Vibrio sp. in the hepatopancreas of white shrimp. Hemocyte count and phenoloxidase activity showed no significant differences (p > 0.05) between diet treatment groups, but hemolymph protein was significantly higher (p < 0.05) in shrimp fed diets containing 15% methanotroph bacteria meal after challenge. The Vibrio colony counts from hepatopancreas in the treatment groups were all significantly lower than the control (p < 0.05). The findings show that methanotroph bacteria meal can entirely replace fishmeal in white shrimp diets and the 15% inclusion of methanotroph bacteria meal in shrimp diet shows no adverse effects on growth performance, feed utilization and survival rate. In addition, shrimp fed methanotroph bacteria meal diets exhibited improved survival rates to an AHPND challenge.

Effects of fish meal replacement with protein mixtures on growth, gonad development and amino acid composition of pre-adult red swamp crayfish, Procambarus clarkii (Girard, 1852) (Decapoda, Cambaridae)

A 100-day growth trial was conducted to evaluate the effects of dietary protein mixtures (PM) adding proportion on both sexes of the red swamp crayfish, Procambarus clarkii (Girard, 1852). Five diets were prepared by replacing 0%, 16.67%, 33.33%, 50%, and 66.67% of fish meal (FM) protein with protein mixtures in feed (designed Diet 1, Diet 2, Diet 3, Diet 4 and Diet 5). The results showed that growth performance presented a decreasing trend with an increase in dietary protein mixture levels. The GSI of female crayfish and the HSI of male crayfish initially increased and then decreased with increasing dietary protein mixtures. Interestingly, the GSI of males fed Diet 5 was higher than that in other groups (). Diet 2 was the best feed for female gonad development and male muscle quality. Females fed Diet 3 had the highest muscle quality among the groups; males had improved gonad development when fed Diet 5.

PSIV-B-18 Performance response of weanling and grower pigs fed graded levels of poultry byproduct meal (PBM) in the diet

Two experiments were conducted to investigate effects of feeding graded levels of PBM on performance of weanling pigs and to evaluate feed preference for PBM-based diets relative to spray-dried plasma protein (SDPP)-based diets. A third experiment evaluated PBM in grower diets on performance. In Exp. 1, 120 pigs [body weight (BW) 7.1 ± 0.6 kg] were randomly allotted to 1 of 5 treatments (0, 1, 2, 3, or 5% PBM) and housed 4 pigs/pen for a 28-d growth trial. In Exp. 2, 60 pigs (BW 6.7 ± 1.4 kg) were randomly allotted to 1 of 3 comparisons including: Comparison 1) 0% PBM vs. 2% PBM, Comparison 2) 0% PBM vs. 2% SDPP, and Comparison 3) 2% PBM vs. 2% SDPP and housed 4 pigs/pen for a 28-d preference trial; pigs were provided ad libitum access to feeders; feeder location was switched 3 times/wk. In Exp. 3, 120 pigs (BW 25.9 ± 2.1 kg) were randomly allotted to 1 of 4 treatments (0, 1.25, 2.5 or 5% PBM) and housed 5 pigs/pen for a 41-d growth trial. Increasing PBM from 0 to 5% in Exp. 1 resulted in no differences in ADG (398, 417, 424, 432, and 428 g) or G:F (0.675, 0.686, 0.733, 0.711, and 0.717). Feed preference results (Exp. 2) demonstrated that pigs consumed a higher percentage (76 vs. 24%, P < 0.01) of their total feed intake from the 2% PBM-based diet compared to the 2% SDPP-based diet (Comparison 3). In Exp. 3, increasing PBM for grower pigs resulted in no differences in ADG (1007, 1025, 1002, and 1025 g) or G:F (0.484, 0.472, 0.484, and 0.478). Thus, feeding PBM up to 5% of the diet had no effect on overall performance of nursery or grower pigs, indicating it is an acceptable option as a feed ingredient.

Effects of constant and diel cyclic temperatures on the liver and intestinal phospholipid fatty acid composition in rainbow trout Oncorhynchus mykiss during seawater acclimation

Background Rainbow trout is an economically important fish in aquaculture and is a model species in environmental physiology. Despite earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on the liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation. Results At the end of growth trial 1, fish at 9 and 12.5 °C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16 °C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestinal phospholipids in fish at 16 °C significantly increased. Two weeks after seawater acclimation, the liver and intestinal PLFA composition adapted to salinity changes. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13 ± 2 °C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased at 13 °C, while fish at 13 ± 2 °C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA at 13 and 13 ± 1 °C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids. Conclusion Temperatures of 9 and 12.5 °C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the membrane fluidity and thickness of the liver and intestine. Compared with constant temperature, diel temperature variation (13 ± 2 °C) can enhance the adaptability of rainbow trout during seawater acclimation.

Effect of a Black Soldier Fly Ingredient on the Growth Performance and Disease Resistance of Juvenile Pacific White Shrimp (Litopenaeus vannamei)

This study was performed as part of developing a functional feed ingredient for juvenile Pacific white shrimp (Litopenaeus vannamei). Here we assess the effects of dietary inclusion of a Black Soldier Fly Ingredient (BSFI) from defatted black soldier fly (Hermetia illucens) larvae meal on growth performance, tolerance to salinity stress, and disease resistance when challenged with Vibrio parahaemolyticus or a strain of white spot syndrome virus (WSSV). A control diet was used for comparison with three test diets including 4.5, 7.5, and 10.5% of BSFI (BSFI4.5, BSFI7.5, and BSFI10.5). After 28 days, all diets with BSFI had improved weight gain, feed conversion ratio (FCR) and specific growth rate (SGR) compared to control. Indeed, SGR was significantly improved from inclusion of 4.5% in the diet, whilst FCR was significantly improved at 7.5% (p < 0.05). During the growth trial, survival was not affected by diet. Shrimp health performance was not significantly affected by the diets across the disease and salinity challenges. Overall, the results indicate that the inclusion of BSFI from H. illucens improves the performance of juvenile L. vannamei.

Dietary Natural Plant Extracts Can Promote Growth and Modulate Oxidative Status of Senegalese Sole Postlarvae under Standard/Challenge Conditions

Plant extracts are known for their high content and diversity of polyphenols, which can improve fish oxidative status. A growth trial with Senegalese sole postlarvae (45 days after hatching) fed with one of four experimental diets—control (CTRL), and supplemented with curcumin (CC), green tea (GT), and grape seed (GS) extracts—was performed to assess if supplementation could improve growth performance and oxidative status. At the end of the growth trial, postlarvae were submitted to a thermal stress to assess their robustness. Sole growth was improved by CC and GS diets when compared to those fed the CTRL. CC and CTRL postlarvae presented the lowest oxidative damage (lipid peroxidation and protein carbonylation values). Stress-related biomarkers (heat shock protein 70 and glutathione-S-transferase) decreased in CC fish compared to those fed the CTRL diet, which might be due to a direct antioxidant capacity. In contrast, oxidative damage increased in GT and GS sole reared in standard conditions. However, after a thermal stress, GT and GS diets prevented the increase of protein carbonylation content and the decrease of antioxidant glutathione, depending on exposure time. Overall, dietary supplementation with natural extracts modulated oxidative status and stress response after a short/long-term exposure to temperature.

Dietary Natural Plant Extracts Modulate Growth Performance and Antioxidant Status of Senegalese Sole Postlarvae

Background Oxidative stress has a direct impact on fish production, affecting both growth and health status. Plant based extracts, such as those from green tea, curcumin and grape seeds, are known for their abundant content and diversity of polyphenols. These bioactive compounds have a high antioxidant capacity making such extracts good additives to include in fish diets potentially improving the oxidative status of fish, and therefore enhancing growth and stress resistance of farmed fish.A growth trial with Senegalese sole postlarvae (45 days after hatching) fed with four experimental diets, a control (CTRL) and three supplemented with natural antioxidants, namely curcumin (CC), green tea (GT) and grape seed (GS) extracts, was performed during 25 days to check if these supplements could improve growth performance and fish oxidative status. Moreover, a thermal stress was applied at the end of the growth trial, to assess the effect of these supplemented diets in stress resistance of sole postlarvae.ResultsSole growth was improved by the dietary inclusion of CC and GS compared to CTRL. Postlarvae from CC and CTRL present the lowest values of oxidative damage (lipid peroxidation and protein carbonylation). Moreover, the fish fed CC showed a decrease in stress related biomarkers (heat shock protein 70 and glutathione-S-transferase) compare to CTRL, which might be due to direct antioxidant capacity. In contrast the supplementation of GT and GS increased the content of oxidative damage in sole reared in standard conditions. However, after a thermal stress exposure both GT and GS treatment seem to prevent the increase of protein carbonylation content and the decrease in the levels of antioxidant glutathione in sole, depending on the time of exposure. ConclusionsOverall, dietary supplementation with these natural extracts modulates oxidative status and stress response after a short/long term temperature increase. The incorporation of curcumin seems to be a safe additive to include in sole diets, enhancing growth and oxidative status. The supplementation of the studied doses of green tea and grape seed extracts in fish diets needs further research as they may act as pro-oxidant depending of the culture conditions.

Effects of Constant and Diel Cyclic Temperatures on The Liver and Intestinal Phospholipid Fatty Acid Composition in Rainbow Trout Oncorhynchus Mykiss During Seawater Acclimation

Background: Rainbow trout is an important economic fish in aquaculture and a model species in environmental physiology. Despite of earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation.Results: At the end of the growth trial 1, fish at 9 and 12.5°C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16°C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestine phospholipids in fish at 16°C significantly increased. Two weeks after seawater acclimation, liver and intestinal PLFA composition adapted to salinity change. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13±2°C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased in 13°C, while fish in 13±2°C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of the growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA in 13 and 13±1°C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids.Conclusion: Temperatures of 9 and 12.5°C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the liver and intestine's membrane fluidity and thickness. Compared with constant temperature, diel temperature variation (13±2°C) can enhance the adaptability of rainbow trout during seawater acclimation.

EFFECTS OF UREA - AMMONIATION AND COTTON SEED CAKE SUPPLEMENTATION ON THE UTILIZATION OF SORGHUM STOVER BY SHEEP

The effects cotton seed cake (CSC) supplementation and urea-ammoniation on utilization of sorghum stover by Yankasa sheep was studied. Chopped sorghum stover was ensiled with fertilizer grade urea at 4% urea (w/w), the urea being dissolved in water to reconstitute the silage to 50% DM. The experiment was a 2x3 factorial design of unammoniated and ammoniated sorghum stover and three levels of CSC supplementation (0.5, 1.0 and 1.5% of the sheep body weight). The growth trial was conducted with 24 yearling sheep, averaging 18.2 kg liveweight and lasted for 60 days. Intake of sorghum stover by sheep was Improved (P<0.05) by urea-ammoniation, not significant (P>0.05). Increasing the level of supplementation with CSC improved (P>0.05) stover intake by sheep fed the ammoniation of unammonlated stover, but resulted in decreased (P>0.05) intake of ammonlated by sheep. Sheep liveweight gains were improved by ammoniation and supplementation (P<0.01). The interaction between urea-ammoniation of stover and supplementation resulted in better (P<0.05) live weight going in sheep. Twelve Yankasa ruang averaging 16.9 kg liveweight were Ammoniation and supplementation did not affect DM, NDF and ADF digestibilities (P>.05), but resulted in increase (P<0.05) in cellulose and hemicellulose digestion. Ammoniation and supplementation resulted in N-balance of the sheep. Ammoniation resulted in marked Increases (P <0.01) in rumen ammonia concentrations, but increasing 50% DM. The material was epsiled above the level of supplementation did not appreciably(P<0.05) silled rumen ammonia concentrate