Nile Tilapia Fingerlings Research Articles

Enhancing growth, immunity, and gene expression in Nile Tilapia (Oreochromis niloticus) through dietary supplementation with avocado (Persea americana) seed powder

This study evaluated the effects of dietary supplementation with different doses (0, 10, 20, 40, and 80 g kg−1) of powdered avocado seed (AS) on the growth performance, immunological response, and gene expression of Nile tilapia (Oreochromis niloticus) reared in a biofloc system over 8 weeks. A total of 300 Nile tilapia fingerlings (average weight 14.67 ± 0.07 g) were randomly assigned to five treatment groups, each with three replicates, and 20 fish per tank. The results demonstrated significant improvements (p < 0.05) in growth and immune response in AS-supplemented fish, particularly in those fed the 10 g kg−1 AS diet (AS10), which showed the most notable increases. In contrast, fish fed higher AS doses (AS20, AS40, and AS80) exhibited no statistically significant differences compared to the control group (p > 0.05). Additionally, the AS10 group exhibited a significant upregulation (p < 0.05) in the mRNA expression of key immune-related genes (IL-1, IL-8, and LBP) and antioxidant-related genes (GST-α, GPX, and GSR) in both liver and intestinal tissues, indicating enhanced immune and antioxidant responses. The highest expression levels were found in the AS10 group. These findings suggest that the inclusion of 10 g kg−1 powdered avocado seed in the diet substantially enhances growth, immune function, and gene expression in Nile tilapia reared in a biofloc system. The results highlight avocado seed as a promising feed additive for improving the sustainability of Nile tilapia aquaculture.

Gradual Replacement of Soybean Meal with Brewer’s Yeast in Fingerling Nile Tilapia (Oreochromis niloticus) Diet, Resulting in a Polynomial Growth Pattern, Independent of Whether Reared in a Biofloc or Clear-Water System

A 60-day feeding experiment was conducted to examine whether (i) soybean meal (SBM) protein in the diet of Nile tilapia (Oreochromis niloticus) can be replaced with protein from spent brewer’s yeast (SBY); (ii) co-rearing with biofloc alters fish growth, feed conversion and protein efficiency compared with rearing in clear water; and (iii) accumulated protein quantity and quality in biofloc acts as a possible feed source for the fish in periods of low feed intake. The fish were reared in either a bio-recirculating aquaculture system (Bio-RAS) or a clear-water RAS (Cw-RAS). In Bio-RAS, the mechanical and biological filters used in Cw-RAS were replaced with an open bioreactor that delivered heterotrophic-based biofloc to the rearing tanks and also acted as a sedimentation trap for effluent water before recirculating it back into the rearing unit. The fish were fed four iso-nitrogenous and iso-energetic diets (~28% crude protein, ~19 MJ kg−1 gross energy) in which SBM protein was replaced with increasing levels of SBY, with triplicate tanks per inclusion level. The results revealed that average fish growth was greater in a biofloc environment compared with clear water and also greater at higher inclusion levels of SBY. However, in both rearing environments, fish growth displayed a second-degree polynomial distribution with increasing SBY inclusion level, with a peak between 30% and 60% inclusion. Fish in the biofloc environment showed better feed conversion ratio and protein retention, likely through ingesting both given feed and biofloc. Biofloc contained a significant amount of accumulated protein with a high biological profile, thereby constituting a possible feed reserve for the fish. A conclusion underlined by the apparent improved feed conversion of Bio-RAS reared fish, where that ingestion of biofloc will reduce the need for external feed per unit growth.

Investigation of the effect of water and feed sourced boron on the growth performance and blood parameters of Nile tilapia, Oreochromis niloticus

AbstractThis study investigated the effects of water and feed‐derived boron on the growth performance and blood parameters of Nile tilapia fingerlings. Two different experiments were designed for this purpose. The first phase of the study determined the LC50 (96‐h) value of boron for Nile tilapia. Fish were then fed in water containing boron at a ratio of 1:20 of the LC50 value. In the second experiment, feed containing boron at different rates (0.00%, 0.01%, 0.05%, and 0.10%) was fed for 40 days. At the end of the feeding period, growth performance, hematology, and blood biochemistry parameters were determined. The study concluded with a calculated LC50 value of 161.053 mg/L boron for Nile tilapia. The initial weight was 12.51 ± 0.79 g; at the end of feeding, the final weights were determined as 26.36 ± 0.15 g for the control and 28.07 ± 0.23, 32.28 ± 0.25 and 24.81 ± 0.48 g for 0.01%, 0.05% and 0.10% of boron feed treatments, respectively. At the end of feeding in water containing boron, the final weight of Nile tilapia was determined as 24.26 ± 0.26 g (LC50/20%). The results showed that feeding Nile tilapia with 0.05% boron‐supplemented feed stimulated growth and positively affected blood parameters, whereas waterborne boron inhibited Nile tilapia growth and negatively affected blood parameters.

Growth and physiological responses of Nile tilapia, Oreochromis niloticus fed dietary fermented sugar beet bagasse and reared in biofloc system

Sugar beet bagasse (SB) is a common agro-industrial waste used in animal feeds. However, its high crude fiber content makes it difficult for fish to digest. Fermentation processes can improve the nutritional value of SB by-products. The study uses Lactobacillus rhamnosus and yeast (Saccharomyces cerevisiae) to ferment SB waste for use as a soybean meal substitute in Nile tilapia fingerlings. This led to an increase in protein, lipid, ash, and nitrogen-free extracts, while the fiber content decreased. Four experimental isonitrogenous (crude protein: 249.2 g kg−1) and isocaloric (gross energy:18.25 MJ kg−1) diets were formulated as follows: a control diet with 0 % LYFSB (L. rhamnosus and yeast fermented SB), and three other diets with LYFSB replacing soybean meal (SBM) at levels of 10 % (LYFSB10 %), 20 % (LYFSB20 %), and 30 % (LYFSB30 %) based on protein content, over a 70-day period. 180 fingerlings of Nile tilapia (average initial weight of 5.19 ± 0.02 g) were placed at random in twelve circular plastic tanks (60 L capacity) with a stocking density of fifteen fish each. Nitrite and ammonia levels decreased as the replacement levels of LYFSB in tilapia diets increased, while nitrate levels showed the opposite trend. The phytoplankton community includes nine species in the biofloc system and four in tilapia gut content, with Chlorophyceae being the most common class, having the highest number in fish-fed diets (7805.67 organism/ml). The study revealed that LYFSB significantly influenced the zooplankton community, with protozoa dominating in biofloc water and rotifer in tilapia gut. LYFSB10 % and LYFSB20 % had the highest bacteria counts. Fish fed with LYFSB10 % and LYFSB20 % diets showed the highest values for specific growth rate (2.51 % day−1) and weight gain (24.92 g fish−1). These diets also exhibited increased activity levels of trypsin, lipase, and amylase enzymes. Increasing the inclusion of LYFSB in fish diets as a replacement for FM improved the intestinal and liver health of fish. The diets with LYFSB10 % and LYFSB20 % showed the highest levels of globulin, total protein, albumin, and IgM, with no significant differences between them. Fish fed LYFSB10 % had lower cholesterol and triglyceride levels. Superoxide dismutase (SOD) and catalase (CAT) activities were highest in fish fed LYFSB10 % and LYFSB20 %, while malondialdehyde (MDA) activity was lowest in the LYFSB30 % diet. The study showed that the biofloc system enhanced water quality and increased the efficiency of tilapia fed LYFSB10 % and LYFSB20 %.

Impacts of substituting fish meal with full-fat or defatted black soldier fly (Hermetia illucens) larvae on growth, quality, and health of Nile tilapia (Oreochromis niloticus) fingerlings

This study investigated the use of black soldier fly (Hermetia illucens) larvae (BSFL), provided in either full-fat (FBSF) or defatted (DBSF) forms, as an alternative protein source in the diet of Nile tilapia (Oreochromis niloticus) fingerlings. Specifically, the influence was assessed of BSFL on growth performance, hematological parameters, body composition, and histology. Nine diets (including the control) were formulated to be isonitrogenous (35 % crude protein) and isolipidic (6 % crude lipid), relying on fish meal as the primary protein source and gradually replacing it with BSFL meal at levels of 25 %, 50 %, 75 %, or 100 % on an equivalent protein basis, corresponding to dietary inclusion levels of 5.25 %, 10.25 %, 15.5 %, and 20.0 %, respectively. Fish with an initial mean weight ± standard deviation of 1.3 ± 0.26 g were fed for 12 weeks until the fish final weight was in the range 24.08–34.95 g. Based on the results, there were no significant (p>0.05) differences in the growth performance or feed conversion ratios among the treatments. Additionally, there were no significant differences in the hematological responses or the proximate body composition. Furthermore, 100 % substitution of fish meal with FSFL and DBSF meal caused blood congestion in the hepatopancreas region and several intraepithelial leukocytes in the intestine. There were no detrimental impacts at levels of 25 %, 50 %, and 75 % on growth performance, hematological responses, body composition, or the intestines or liver histological characteristics of the O. niloticus fingerlings. This information should provide useful guidance for the management of Nile tilapia, an economically important species.

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Antagonistic effects of Bacillus subtilis-derived chitosan nanoparticles on growth performance, stress biomarkers, and histological alterations of cadmium-intoxicated Nile tilapia fingerlings

Heavy metals including cadmium (Cd) are one of the major persistent and non-biodegradable wastewater pollutants. However, Cd reaches the aquatic ecosystem via industrial and agricultural waste discharges and causes serious deterioration in the welfare status of aquatic animals. The use of feed supplements with immune-stimulants to mitigate the toxic influences of heavy metals including Cd is a much more intriguing point. Thus, the current experiment used the bio-synthetized chitosan nanoparticles derived from Bacillus subtilis (Bs-CNPs) as a feed supplement and evaluated its ameliorative impacts on the growth and welfare status of Cd-intoxicated Nile tilapia (Oreochromis niloticus). Bifactorial design (3 Bs-CNPs levels × 3 Cd levels) was used in the current study where Nile tilapia fingerlings (58–63 g) were fed on 0.0, 2, and 4 g Bs-CNPs/kg feed alongside with exposing to 0.0, 0.392, and 0.784 mg Cd/L for 60 days to represent nine treatments as follows: T1: control group (no Cd exposure; no Bs-CNPs supplement); T2 and T3: fish were intoxicated with 0.784 and 0.392 mg Cd/L, respectively; T4 and T5: fish fed on 2 and 4 g Bs-CNPs/kg feed, respectively; T6 and T7: fish were fed on 2 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively; and T8 and T9: fish were fed on 4 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively. It is noted that the Cd-intoxicated fish exhibited significant retardation in growth performance and digestive enzyme activities with a decline in their survival rate compared to the control group (T1). The results also revealed that exposing fish to Cd toxicity alone with no feed supplement (T2 and T3) experienced abnormal clinical signs and behavioral changes. Compared with the control group (no Cd with no Bs-CNPs), highest values of cortisol, glucose, aspartate and alanine aminotransferase, and acetylcholine esterase activity were found in fish fed on the control diet along with exposure to 0.784 mg Cd/L. Higher Cd restudies in liver, intestine, gills, kidney, and muscles tissues were detected in fish exposed to 0.784 mg Cd/L alone and the sequence order of Cd levels in different fish organs is intestine > gills > liver > kidney > muscles. Remarkable pathological alterations in hepatic and intestinal tissues were also observed. On the other hand, feeding Nile tilapia on Bs-CNPs-enriched diets alone with no Cd exposure enhanced their growth performance, digestive enzyme activities, and hematological parameters with no Cd residues in fish organs. Interestingly, feeding the Cd-intoxicated fish on diets with Bs-CNPs (4 g/kg feed) returned their growth, digestive enzymes, hematological, and biochemical parameters to approximate those of the control group. Furthermore, these treatments showed histopathological alteration recovery in the intestine and liver tissues is similar to those in the control group (no Cd with no Bs-CNPs). Fish fed on Bs-CNPs levels with no Cd exposure showed no Cd residues in different fish organs. The Cd levels in different organs of fish exposed to 0.392 mg Cd/L along with feeding on Bs-CNPs (4 g/kg feed) were lower than those in Cd-exposed fish treatments. Consequently, the current study evoked that feeding Nile tilapia fingerlings on Bs-CNPs (4 g/kg feed) could enhance their growth performance and protect the fish from the Cd toxicity that may occur in the aquatic ecosystem.

Impact of Inclusion Ashwagandha (Withania somnifera) Root Powder as a Growth Promoter in the Diet of the Nile tilapia (Oreochromis niloticus) Fingerlings

Impact of Inclusion Ashwagandha (Withania somnifera) Root Powder as a Growth Promoter in the Diet of the Nile tilapia (Oreochromis niloticus) Fingerlings

Investigating the Effects of Extended Acclimatization Period on the Growth and Survival of Sex-Reversed Nile Tilapia (Oreochromis niloticus) Fingerlings through Communal Rearing

Investigating the Effects of Extended Acclimatization Period on the Growth and Survival of Sex-Reversed Nile Tilapia (Oreochromis niloticus) Fingerlings through Communal Rearing

Elucidating the effect of dietary neem (Azadirachta indica) on growth performance, haemato-biochemical, immunonological response, and anti-pathogenic capacity of Nile tilapia juveniles.

This investigation attempts to evaluate the effect of diet additives via aqueous or ethanolic herbal extracts from Azadirachta indica leaves on Nile tilapia, Oreochromis niloticus. Five dietary categories were assigned to the fish: the first category (N1, with no extract) was kept under control conditions; two categories contained aqueous extract (N2 (1.0g/kg) and N3 (2.0g/kg); and two categories contained ethanolic extract, N4 (1.0g/kg) and N5 (2.0g/kg), with each group being fed for 60 days. After the feeding trial, Aeromonas hydrophila was injected intraperitoneally into fish for 14 days; fish mortality was recorded during this period. The results showed that the fish-fed dietary A. indica significantly improved growth performance and intestinal health (digestive enzymes and intestinal morphology), especially in the N4 and N5 categories. However, N4 and N5 categories demonstrated a significant decrease in AST and ALT activities and an increase in total protein, serum albumin, globulin, growth hormone (GH), leptin hormone (LEP), hemoglobin, white blood cells, and hematocrit (P < 0.05) in comparison with the control category (N1). Compared to the control category, the N4 and N5 categories have revealed a significant reduction in MDA activity and improvements in immunological activities (lysozyme, complement C3, and nitric oxide) and antioxidant enzymes (CAT, SOD, and GPX). Moreover, in tilapia-fed A. indica, the expression of IL-8, IL-1β, and Nf-κb genes was downregulated partially in the N4 and N5 categories than the control category. In contrast, the lysozyme, C3, GPX, and CAT genes were upregulated partially at N4 and N5 compared to the control category. Following the bacterial challenge, fish in the N4 and N5 categories also displayed the lowest fish mortality compared to the control category. The ethanolic extract displayed a more potent resistance against the parasite Cichlidogyrus tilapia in vitro than the aqueous and control categories, partially at 2g/L. According to these findings, an ethanolic neem extract (2.0g/kg feed) activates the immune system and antioxidant response in Nile tilapia fingerlings, improving growth and fish resistance to parasitic and bacterial infections.

Interactive effects of water temperature and dietary protein on Nile tilapia: growth, immunity, and physiological health

Optimizing fish performance depends on several factors, with dietary protein levels and rearing temperature playing important roles. In this study, Nile tilapia fingerlings (Oreochromis niloticus) weighing an average of 20.00 ± 1.26 g were divided into nine groups (in three replicates). Each group was subjected to different water temperatures (26 °C, 28 °C, and 30 °C) and received one of three dietary protein levels (20%, 25%, and 30%) for two months. Our findings indicate that higher temperatures, particularly at 30 °C, increased water electrical conductivity and total dissolved salts, especially noticeable in fish fed 25% or 30% crude protein (CP). Lower total ammonia nitrogen levels were observed at 28 °C with 25% CP, 30 °C with 30% CP, and 26 °C with 30% CP. Hepatic growth hormone receptor 1 and insulin-like growth factor 1 expression gradually rose with higher dietary CP percentages in fish at 26 °C but declined in those at 30 °C, albeit remaining higher than in the 28 °C groups with 25% CP. Fish at 28 °C showed the best final body weights and growth performance when fed 20% or 25% CP, with no significant difference between these groups. Hepatic leptin expression did not differ significantly among groups, but hepatic fatty acid binding protein expression notably increased in fish fed 30% CP at both 26 °C and 30 °C compared to those at 28 °C with 25% CP. Within the same temperature group, fish fed 30% CP exhibited higher globulin levels, particularly thriving at 28 °C or 30 °C. Hepatic mucin-like protein expression significantly increased across all groups, especially in fish at 30 °C with 30% CP compared to those at 28 °C with 25% CP. Hepatic lysozyme expression also increased notably in fish at 30 °C with 30% CP. Notable changes in superoxide dismutase, catalase, and glutathione peroxidase expression were observed, with the highest serum superoxide dismutase and catalase activities recorded in fish at 30 °C with 25% CP. Overall, dietary protein levels of 25% and 30%, combined with temperatures of 28 °C and 30 °C, yielded favorable outcomes, particularly favoring 28 °C with 25% protein.

Reversing the detrimental effects of high stocking density in Oreochromis niloticus juveniles using coenzyme Q10 and l-carnitine dietary supplementation

A 14-week trial was undertaken to examine the effects of coenzyme Q10 (CQ10) and l-carnitine (LC) dietary supplementation, either individually or in combination, on the feed intake, growth, blood biochemistry, immunity, economic viability, and body composition of Nile tilapia fingerlings reared at a high stocking density. The study involved eight groups of 450 tilapia juveniles, with an average weight of 6.083 ± 0.09 g, assigned to different treatments. Two groups were fed a basal diet and stocked at densities of 30 and 60 fish per m3, respectively. The remaining groups were reared at a high stocking density of 60 fish/ m3 and fed diets fortified with LC at 150 mg (G3), LC at 300 mg (G4), CQ10 at 20 mg (G5), CQ10 at 40 mg (G6), LC at 150 mg + CQ10 at 20 mg (G7), or LC at 300 mg + CQ10 at 40 mg (G8) per kg of diet. The findings revealed that high stocking density had an adverse impact on tilapia growth performance. Nevertheless, the inclusion of LC and CQ10 in the diet, whether separately or in combination, significantly improved growth parameters and enhanced survival rates. The G6, G7, and G8 groups showed the most significant improvements in growth and survival. High stocking density resulted in decreased moisture and crude protein content, while LC and CQ10 supplementation increased these components and reduced crude fat and ash content. High stocking density negatively impacted blood metabolites, leading to elevated levels of aspartate aminotransferase, alanine aminotransferase, creatinine, and urea-N, as well as decreased total protein and albumin. However, supplementation with LC and CQ10 effectively alleviated these effects, improving the levels of these parameters. All supplemented groups showed enhanced lysozyme activity and IgM concentration, with the greatest improvements observed in the G6, G7, and G8 groups. Economic analysis indicated that LC and CQ10 supplementation improved final and relative margin, except in the G4 group. In conclusion, the combined supplementation of LC and CQ10 shows promise in enhancing productivity and profitability in tilapia farming under high stocking density conditions, particularly in concrete tanks.

Effects of water additive mixed probiotics on water quality, growth performance, feed utilization, biochemical analyses and disease resistance against Aeromonas sobria of Nile tilapia

The present study examined the effects of water additive mixed probiotics on water quality, growth performance, feed utilization, biochemical analyses and disease resistance against Aeromonas sobria of Nile tilapia (Oreochromis niloticus). Triplicate groups of Nile tilapia fingerlings (46 g) were fed a commercial diet (ALLER AQUA FEED) in four water treatments control (0.0 g/m3), T1 (0.0010 gm m-3 day-1), T2 (0.0015 gm m-3 day-1), T3 (0.0020 gm m-3 day-1) of probiotic ( AquaStar® Pond) for 60 days. The water quality parameters particularly total ammonia nitrogen (TAN) and ammonia (NH3) decreased significantly (P ≤ 0.05) in all three water treatments when compared to the control treatment. The better values of growth performance, feed utilization and hematology recorded of probiotic groups. The results also showed that fish reared in three water treatments with additive probiotics had a lower mortality when challenged with Aeromonas sobria. Hence, the water additive probiotic used in this study is a promising solution as an alternative product to improve the water quality, growth, and health of O. niloticus.

The effect of dietary administration of Saussurea lappa root on performance, blood biochemical indices, redox status, innate immune response, intestinal microbial population and resistance against A. hydrophila infections of Tilapia Fingerlings

AbstractThis experiment was performed to identify the influence of dietary Saussurea lappa root (SLR) on the performance and general health status of Nile Tilapia fingerlings (O. niloticus). Four formulated diets with different SLR levels of 0.0, 2.5, 5 and 10 g/kg, respectively, were afforded to fingerling fish (15.42 ± 0.05 g) for 8 weeks. The feed efficiency ratio (FER), feed intake (FI) and feed conversion ratio varied with dietary SLR level in a linear model and a high feed efficiency rate was recorded at the 10 g/kg group, while FI and FCR exhibited an opposite trend (P &lt; 0.001). Dietary SLR level influenced serum protein constituents, liver and renal function enzymes, triglycerides, cholesterol and glucose (P &lt; 0.001). Serum Catalase (CAT), total antioxidant capacity (T‐AOC) and superoxide dismutase (SOD) remarkedly increased with dietary SLR level and attained a level at 10 g/kg. Furthermore, serum lysozyme, complement C3 (C3), IgA and IgD were stimulated by 10 g/kg SLR. Intestinal digestive enzymes (lipase and amylase) increased with SLR level up to 10 g/kg. As the dietary SLR level raised, the cumulative survival percentage aginst A. hydrophila challenge increased and then reached a maximum at 10 g/kg SLR group. Moreover, gene expression of pro‐inflammation cytokines (TNF‐2a, IL‐1β, and IL‐10) in liver and kidney transcriptomes demonstrated effective immunostimulant capabilities of greater SLR inclusion levels in fish diet. Meanwhile, intestinal microbial investigation, revealed that high levels of SLR in tilapia fish feed significantly suppressed total bacterial count, and pathogenic bacterial count (such as, E. coli, Coliform, Aeromonas spp, Pseudomonas spp.), and stimulated lactic acid bacteria development. Finally, it is recommended to include a high level of SLR (5 or 10 g/kg) in the diet of O. niloticus fingerlings to enhance feed efficiency, antioxidant characteristics, and immunological response against bacterial infections.

Physiological Changes in Nickel-exposed Nile Tilapia Oreochromis niloticus during Exposure and Recovery Periods

Heavy metals are a significant problem in aquatic ecosystems as they are toxic and tend to accumulate, immediately affecting fish physiology. The present investigation was carried out to evaluate the sub-lethality of Nickel chloride on fingerlings of Nile tilapia, Oreochromis niloticus on long-term exposure to it is below safe concentrations1/fifth (9.39 ppm) and 1/10th (4.69 ppm). The physiological studies revealed a significant reduction in Oxygen Consumption Rate (OCR), Ammonia-N Excretion Rate (AER), Oxygen Rate (O: R) and Food Consumption Rate (FCR) and behavioural changes during accumulation and depuration phases. Limited recovery was obtained in all the physiological parameters after depuration for 28 days from the end of the accumulation period.

Water quality change, growth performance, health status in response to dietary inclusion of black soldier fly larvae meal in the diet of Nile tilapia, Oreochromis niloticus

Abstract With increasing intensive aquaculture production, the search for nourishing, environmentally, and economically viable fishmeal (FM) alternative is an endless approach. Therefore, the present study examines the effect of the use of black soldier fly, Hermetia illucens, larvae meal (BSFM) as an alternative protein for FM in the diet of Nile tilapia, Oreochromis niloticus, on nitrogen wastes, zootechnical performance, body composition, and hematobiochemical parameters. A total of 315 Nile tilapia fingerlings (4.11±0.12 g/fish) were divided into seven treatments in triplicate. The fish were stocked in glass aquaria (50 × 40 × 30 cm; 60 L each) at a rate of 15 fish per aquarium. Experimental diets contained BSFM at increasing levels of 0, 5, 10, 15, 20, 25, and 30% as FM replacers were offered twice daily to apparent satiation for 84 days. The results revealed that BSFM replacements significantly (P = 0.001) enhance water quality and reduce the total ammonia, NH3, and NO2 levels compared to the control. The growth performance, feed conversion ratio, and survival were improved with increasing BSFM meal inclusion levels up to 25% (P = 0.001, 0.017, and 0.001, respectively). However, the zootechnical performance of the experimental fish started to decline with increasing replacement levels to 30%. Also, by an increase in BSFM level to 25%, hematobiochemical markers were considerably (P≤0.01) enhanced. The liver and kidney function indicators improved (P = 0.001) with dietary BSFM. The economic evaluation revealed that feed costs and fish weight gain were decreased by increasing BSFM levels in fish diets. The current study highlighted the potential environmentally beneficial use of BSFM as an FM replacer in terms of reducing water nitrogen waste levels and improving growth performance, health status, and enhancing the economic feasibility of the commercial tilapia diet.

Effects of Shrimp Shell-Derived Chitosan on Growth, Immunity, Intestinal Morphology, and Gene Expression of Nile Tilapia (Oreochromis niloticus) Reared in a Biofloc System.

Chitosan (CH) shows great potential as an immunostimulatory feed additive in aquaculture. This study evaluates the effects of varying dietary CH levels on the growth, immunity, intestinal morphology, and antioxidant status of Nile tilapia (Oreochromis niloticus) reared in a biofloc system. Tilapia fingerlings (mean weight 13.54 ± 0.05 g) were fed diets supplemented with 0 (CH0), 5 (CH5), 10 (CH10), 20 (CH20), and 40 (CH40) mL·kg-1 of CH for 8 weeks. Parameters were assessed after 4 and 8 weeks. Their final weight was not affected by CH supplementation, but CH at 10 mL·kg-1 significantly improved weight gain (WG) and specific growth rate (SGR) compared to the control (p < 0.05) at 8 weeks. Skin mucus lysozyme and peroxidase activities were lower in the chitosan-treated groups at weeks 4 and 8. Intestinal villi length and width were enhanced by 10 and 20 mL·kg-1 CH compared to the control. However, 40 mL·kg-1 CH caused detrimental impacts on the villi and muscular layer. CH supplementation, especially 5-10 mL·kg-1, increased liver and intestinal expressions of interleukin 1 (IL-1), interleukin 8 (IL-8), LPS-binding protein (LBP), glutathione reductase (GSR), glutathione peroxidase (GPX), and glutathione S-transferase (GST-α) compared to the control group. Overall, dietary CH at 10 mL·kg-1 can effectively promote growth, intestinal morphology, innate immunity, and antioxidant capacity in Nile tilapia fingerlings reared in biofloc systems.

Dietary low‐fat content supplemented with oxytetracycline impairs physiological functions in Nile tilapia (Oreochromis niloticus) fingerlings

AbstractNutrition modulates the vulnerability of animals to xenobiotics insults including antibiotics in cultured fish. However, studies exploring the role of low‐fat diet (LFD) in modulating adverse effects of antibiotics are currently limited. This study explored the physiological effects of feeding LFD supplemented with oxytetracycline (OTC) in Nile tilapia (Oreochromis niloticus) fingerlings. Thirty Nile tilapia (8.64 ± 0.44 g) were tagged and randomly stocked into three tanks and fed on a control diet (CD, 70 g/kg lipid), LFD (20 g/kg lipid) and the LFD supplemented with 2.00 g/kg diet of OTC (80 mg/kg body weight/day), hereafter LFD + OTC for 9 weeks. The results indicated that the Nile tilapia fed on LFD + OTC reduced growth performance and feed utilization efficiency than those fed on CD and LFD. Moreover, the fish fed on LFD + OTC had lower body composition, nutrients digestibility and mesenteric fat index than those fed on CD and LFD. Feeding the fish with LFD + OTC decreased antioxidant capacity in the liver than those fed on CD and LFD. The Nile tilapia fed on LFD + OTC increased hepatotoxicity than those fed on CD and LFD. Feeding the Nile tilapia on LFD + OTC decreased immunity response in the kidney and liver than those fed on CD and LFD. The LFD + OTC affected nutrients metabolism in the liver and serum than other diets. Taken together, feeding LFD with OTC impairs physiological functions of Nile tilapia by inhibiting growth performance, antioxidant capacity, immunity response and nutrient metabolism.

Effect of replacing soybean meal with fermented cottonseed meal on growth performance and feed utilization of the Nile Tilapia (Oreochromis niloticus) fingerlings

Effect of replacing soybean meal with fermented cottonseed meal on growth performance and feed utilization of the Nile Tilapia (Oreochromis niloticus) fingerlings