Effect of feeding frequency on growth, proximate composition, and hemocyte status of Litopenaeus vannamei and Macrobrachium rosenbergii under nursery co-culture in a biofloc system

A 3-week nursery phase for giant river prawn, Macrobrachium rosenbergii post larval (PL), was conducted in biofloc systems at increasing carbon–nitrogen (C-N) ratios of 10:1 (C-N10), 15:1 (C-N15), 20:1 (C-N-20) and 25:1 (C-N25) versus a clear water system (40% water exchange every 2 days and no additional carbon). A total 400 PLs (15.90 ± 1.29 mg) were cultured in tanks (100 L) filled with brackish water (12‰), and corn starch was the carbon source. Growth, survival, feed conversion ratio (FCR), whole body proximate composition, water quality parameters, biofloc volume, zooplankton and proximate composition were measured. Total ammonia nitrogen (TAN) and nitrite nitrogen (NO2-N) were significantly lower in all biofloc systems as well as containing increased zooplankton groups (ciliates, rotifers and nematodes). Specific growth rate (SGR) was similar between the control (9.29 ± 0.35% day−1) and the CN-20 (9.47 ± 0.18% day−1) and CN-25 (9.34 ± 0.20% day−1) treatments; however, SGR significantly declined in the C-N10 treatment (8.03 ± 0.10% day−1). Survival was unaffected by treatments while a higher survival (87.34%) was in CN-20 and it was followed by CN-25 (80.34%), control (80.33%), CN-10 (77.0%) and CN-15 (76.66%) respectively. The best FCR was in the C-N20 treatment at 2.65, but was not statistically different than the control at 3.12. However, crude protein of the PLs was significantly higher in the C-N15, C-N20 and C-N25 treatments compared with the control. The present findings indicate that the water quality was better managed in the biofloc treatments compared with the control; however, lower C-N ratios of 10 and 15 can negatively impact prawn growth compared with the control or higher C-N ratios of 20 or 25.

Biofloc technology is beneficial for prawn farming because it saves resources, protects the environment, and uses less energy. This study was conducted to evaluate the yield performance of freshwater prawns (Macrobrachium rosenbergii) cultured in a biofloc system at various densities (T-1 = 50 prawn/m², T-2 = 70 prawn/m², and T-3 = 90 prawn/m²). The experiment, which was conducted over 180 days with three replications, utilized rectangular aquaria with a water volume of 100 liters. Before stocking, post-larvae (12 days old) were nursed in a mother tank for 40 days. Throughout the experiment, water quality parameters, such as temperature, dissolved oxygen, and pH, were monitored daily. Total ammonia nitrogen (TAN) was measured three times a week, whereas nitrite (NO2), alkalinity, and hardness levels were assessed weekly. After the experiment, we evaluated growth performance metrics, including weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and survival rate. The plankton densities in the experimental units were also observed. Except for alkalinity, all water quality variables remained within the optimal range. The maximum weight gain, SGR (%), efficient FCR, and survival (%) were 35.35±8.54, 2.04±0.08, 1.91±0.10, and 74.00±9.57, respectively, in T-1. In contrast, the highest planktonic density (46.8×104 cells/L) was found in T-3. Finally, the results suggest that a stocking density of 50 prawns/m2 yielded better results in a zero water exchange biofloc culture tank and can enhance prawn culture in the farmer’s field.

This study aims to investigate the effect of using different probiotics on growth, survival rate, and feed conversion rate of African catfish on the biofloc system. The study was conducted at the SMK PP Negeri Mataram Laboratory from August to September 2020. The research design used a completely randomized design (CRD) with 4 treatments with 3 replications. Data collection was carried out by measuring fish length and fish weight. The data analyzed were daily weight growth rate, daily length growth rate, specific growth rate, survival rate, feed conversion rate, growth pattern, and condition factors. Growth rates, survival and feed conversion rates were analyzed using the ANOVA method and LSD test. The results indicated that the growth rate of daily weight, length growth rate, specific growth rate, and conversion rate has optimal in the treatment of Bacillus + Lactobacillus probiotic. In this treatment, the average daily weight growth rate in the treatment was 0.13 gr/day, the daily length growth rate for African catfish was 0.130 cm/day, the specific growth rate was 1.76%/day, and the average feed conversion rate of 0.641. The highest survival rate also occurred in the treatment of Bacillus + Lactobacillus probiotics with an average of 81.33%. The growth pattern of African catfish with the biofloc system is negative allometric, the coefficient value (b) is less than 3. The condition factor for African catfish is categorized as flat.

The aim of this research is to analyze the performance of growth and survival of climbing perch (Anabas testudineus Bloch) which was raised in bioflocs and conventional systems. It investigated the difference in the initial size of the fry stocked with climbing perch has effect. The experimental design used in this study was a Factorial Completely Randomized Design (CRD) with 2 factors and 3 replications: Factor A: climbing perch aquaculture Systems; A1: climbing perch in conventional system of; A2: the climbing perch in bioflocs system; Factor B: Initial Size of fry Stocking; B1: fry size 3 ± 0.5cm; B2: fry size 5 ± 0.5cm and B3: fry size 7 ± 0.5cm. The research was conducted for 90 days with daily growth parameters (SGR), weight and length growth, survival rate, food conversion, flocsvolume density (FVD), and main water quality parameters (water temperature, pH, dissolved oxygen and dissolved ammonia).The results showed that the bioflocs system was able to increase the average growth in the range of 12-67% with an average of 29.73% when compared to conventional systems. The highest value for the daily growth rate or Specific Growth Rate (%/day) was for fry with a size of 7 cm in the bioflocs system (8,419%). The fry size of 3 ± 0.5cm in the bioflocs system had the highest difference in standard length (4.33 cm) while the highest average length during maintenance was the seed size of 7 ± 0.5 cm in the bioflocs system. The survival results of climbing perch fish during the study were based on the highest score on the seed size of 3 ± 0.5cm in the bioflocs system. The survival range of the bioflocs system is 94.89 - 99.67% and that of the conventional system is 82.00 - 94.26%. Thus the bioflocs system is able to increase survival in the range of 5-14% when compared to conventional systems. The bioflocs system is able to provide better feed efficiency than conventional systems in the range of 34-39%. The average value of floc volume density (FVD) in the bioflocs system is in the range of 5.35 – 8.16 ml/L, which is still ideal but can still be improved. Water temperature during the study period, air and water temperatures ranged from 28.54 to 28.71 (ºC), the degree of acidity in all treatments was in the range 6.34 – 7.27, dissolved oxygen levels were in the range 5.77 – 6.90 mg /L) while the average measurement results for ammonia levels (mg/L) were in the range of 0.49 – 0.57 mg/L. The temperature ranges in the studies on conventional and bioflocs systems are within the acceptable range for fish farming Water temperature during the study period, air and water temperatures ranged from 28.54 to 28.71 (ºC), the degree of acidity in all treatments was in the range 6.34 – 7.27, dissolved oxygen levels were in the range 5.77 – 6.90 mg /L) while the average measurement results for ammonia levels (mg/L) were in the range of 0.49 – 0.57 mg/L.

Probiotics are gaining popularity both empirically and scientifically as eco-friendly alternatives in aquaculture. The present research proposed to examine the influences of selective probiotics on the growth, hematology, microbes, and morphology of the intestine of stinging catfish (Heteropneustes fossilis) in a biofloc system. Additionally, this study evaluated the benefit–cost ratio (BCR) of specific probiotics used in the biofloc system. Stinging catfish fingerlings (average weight 0.86 ± 0.26 g) were equally distributed (250 fingerlings/400 L water-filled PVC tank) into three treatment groups and reared for 16 weeks. Two commercial probiotics (CP-1 and CP-2) and one laboratory-developed probiotic were used in the study. The results showed significantly higher growth (weight gain and specific growth rate), feed efficiency, improved intestinal microbiota, and enhanced morphology in fish reared with laboratory-developed probiotics in the biofloc system. Moreover, indicators of increased immune responses, such as enhancements in the intestinal mucosal fold, width of enterocytes and lamina propria, and abundance of goblet cells, were also observed in fish reared with laboratory-developed probiotics. The BCR, which determined business profitability, was also highest for the laboratory-developed probiotics in the biofloc system. Therefore, the results suggest that laboratory-developed probiotics are economically viable and environmentally friendly growth stimulators for stinging catfish culture in a biofloc system.

The current study was carried out to examine the effects of four different experimental salinities (T1 = 0‰, T2 = 5‰, T3 = 10‰, and T4 = 15‰) on growth, water quality, proximate composition, total bacterial (TB), and hemocyte counts of white leg shrimp (Litopenaeus vannamei) and giant prawn (Macrobrachium rosenbergii) in biofloc based nursery bi‐culture system for 6 weeks. A total of 12 cylindrical plastic tanks (125 L) filled up 100 L water for rearing L. vannamei and M. rosenbergii post‐larvae (PLs) at an equal ratio: (50 L. vannamei: 50 M. rosenbergii). At the end of the experiment, for L. vannamei, the significantly higher (p < 0.05) growth rate was recorded in T4 (15‰) compared to the other treatments. For M. rosenbergii, a significantly higher (p < 0.05) growth rate was recorded in T2 (5‰) than in other treatments. Similar to growth, the best (p < 0.05) feed conversion ratio (FCR) for ‐L. vannamei was found at T4 (15‰) while it was at T2 (5‰) forM. rosenbergii. Gross return, net profit, and benefit–cost ratio (BCR) analysis revealed higher profit T4 (15‰) than T3 (10‰), T2 (5‰), and T1 (0‰). TB counts were found to be significantly greater (p < 0.05) in T4 than other treatments. Hemocyte counts for L. vannamei were significantly higher (p < 0.05) in T4 (15‰) than T3 (10‰), T2 (5‰), and T1 (0‰) and for M. rosenbergii hemocyte was significantly higher (p < 0.05) in T1 (0‰) than T2 (5 ‰), T3 (10 ‰), and T4 (15‰). Therefore, it can be suggested that 15‰ salinity will be the best condition for the nursery bi‐culture of white leg shrimp (L. vannamei) and giant prawn (M. rosenbergii) in the biofloc system.

The giant freshwater prawn, Macrobrachium rosenbergii, is a valuable aquaculture species known for its rapid growth, adaptability to environmental variations, and high nutritional value. However, challenges such as high mortality rates, algal blooms, dissolved oxygen depletion, and pathogen outbreaks constrain its cultivation. The overuse of antibiotics in aquaculture raises significant environmental and health concerns, including antimicrobial resistance. This study explores the potential of sodium alginate, a natural polysaccharide derived from brown algae, as a prebiotic and immunostimulant for improving growth and feed efficiency in M. rosenbergii. Juvenile prawns (~0.2 g) were cultured for 60 days and fed experimental diets supplemented with sodium alginate at concentrations of 0 g/kg (control, T0), 1.0 g/kg (T1), 2.0 g/kg (T2), and 3.0 g/kg (T3). Growth performance, feed utilization, and survival rates were assessed bi-weekly. Results showed significant improvements (p<0.05) in growth parameters, including mean weight gain (MWG) and specific growth rate (SGR), in prawns fed a 2.0 g/kg sodium alginate diet (T2). At the end of the experiment, T2 recorded the highest mean weight, MWG, SGR, and lowest feed conversion ratio (FCR, 2.395 ± 0.068), demonstrating superior feed utilization efficiency. In contrast, prawns fed a 3.0 g/kg sodium alginate diet (T3) showed reduced growth performance and feed efficiency. This study highlights the efficacy of sodium alginate as a dietary supplement to enhance growth, feed efficiency, and sustainability in freshwater prawn aquaculture, with the optimal dosage identified as 2.0 g/kg. These findings support sodium alginate's potential as an eco-friendly alternative to antibiotics in aquaculture systems.

This research aim to determine the optimal dose of additional probiotic in feed toward the growth performance and survival rate of tambaqui ( Colossoma macropomum ) by using biofloc system. This research was conducted on March 30-May 9, 2018 at Technical Service Unit (UPT) of Hatchery, Marine and Fisheries Faculty, University of Riau. This research was using experimental method by completely random design (RAL) one factor with three replications. The treatments were: A: 0 g/kg of feed (control), B: 0,5 g/kg of feed, C: 1 g/kg of feed, and D: 2 g/kg of feed. The probiotic ( Bacillus sp) The results showed that a different doses of additional probiotic affecting the growth performance and the survival rate of tambaqui using biofloc system. In addition, it also affected the absolute weight growth, absolute length growth, feed efficiency and feed conversion ratio.The optimal dose was at 2 g/kg of feed as it showed significantly different results compared to control and was not differ significantly at higher doses. So that while being applied in terms of economy, 2 g/kg was the most efficient dose, by giving the absolute weight growth was 37,62 g, absolute length was 6,91 cm, specific growth rate was 7,00%, feed efficiency was 104,16%, feed conversion ratio was 0,96 and survival rate was 100%.

Mulberry leaf extract (MLE), an active substance extracted from mulberry leaves, is known to have a positive effect on several physiological functions. The current study examined the effects of dietary MLE in feed at concentrations 0, 3.0, 6.0, 9.0, 12.0 and 15.0 g/kg on the growth performance and gastrointestinal and hepatic functions of Andrias davidianus for 12 weeks. Results indicated that the final body weight, weight gain rate (WGR), specific growth rate and feed intake (FI) of A. davidianus increased with the increase in the dietary MLE up to 9.0 g/kg and declined thereafter, while the feed conversion ratio (FCR) exhibited an opposite trend. Meanwhile, A. davidianus with a dietary intake of 9.0 g/kg MLE showed higher levels of crude protein in muscles and lower levels of moisture and crude lipid levels in the liver and muscles when compared with the control. In addition, dietary MLE increased the density and length of the villi and decreased the cavity rate in the foregut, enhancing the activities of carbonic anhydrase, H+-K+-ATPase, pepsin, intestinal trypsin, lipase and Na+-K+-ATPase (p < .05) in the stomach. Furthermore, dietary MLE increased the intestinal and hepatic superoxide dismutase activities and total antioxidative capacities but decreased their malondialdehyde contents in A. davidianus. Dietary MLE also significantly increased the immune parameters, and the plasma total protein, albumin and immunoglobulin M contents but significantly decreased the aspartate aminotr-ansferase, alanine aminotransferase and diamine oxidase activities, and the total bilirubin, direct bilirubin, cholesterol, triglyceride and endotoxin contents (p < .05). In conclusion, a quadratic regression analysis of WGR and FCR indicated that the optimum level of MLE for A. davidianus was between 8.21 and 8.30 g/kg of the diet.

n 84-day experiment was conducted to investigate the effects of two dietary protein levels 30 & 35% CP & three feeding frequencies 2, 3 & 4 times a day (8:0 and 11.0 h), (8.0, 11.0 and 14.0 h) and (8.0, 11.0, 14.0 and 17.0 h) on growth performance and feed utilization of the freshwater prawn, Macrobrachium rosenbergii with the Nile tilapia, Oreochromuis niloticus fry in a polyculture system. The experiment was conducted in small-scale hapas, 3.75 m -3 each in triplicates. Irrespective of polyculture system, prawn PL fed diet containing 35% CP 4 times a day had significant (P≤0.05) the highest final body weight (FBW), weight gain (WG), specific growth rate(SGR) and best feed conversion ratio (FCR) values among all treatments. Meanwhile, the Nile tilapia fed on diet containing 35% CP at 2 times/day recorded the highest significant FBW, WG, and best FCR among all treatments. The highest significant total biomass weight (kg hapa -1 ), and gain (kg hapa -1 ) and feed consumption (kg hapa 1 ) were obtained for prawn and tilapia feed the diet containing 35% protein. No significant differences (P≤0.05) were observed for SGR, FCR and S among all experimental hapas. The same trend was recorded for the different feeding frequencies. The highest values of the whole body CP, EE, ash and gross energy content were recorded for prawn fed on 30% diet at twice per day. No clear trend was observed for body composition of the Nile tilapia fry except for the highest lipid content (P ≤ 0.05) recorded for the fish fed on 30% CP diet 2 times per day. The findings of the current trials revealed that, feeding frequency has a great effect on growth performance and feed utilization efficiency of the freshwater prawn M. rosenbergii PL and the Nile tilapia fry. Feeding frequency 4 times per day for M. rosenbergii PL either 2 or 3 times per day for Nile tilapia fry is recommended under similar rearing condition to achieve best performance for both animals.

Local plant-based resources are widely used as ingredients in artificial feed formulations; the problem with these resources is that they contain anti-nutritional substances, namely phytate acid. An approach that can be used to overcome phytate acid is the addition of phytase to the artificial feed. The success of common carp (Cyprinus carpio) fish fingerling cultivation is supported by feed management in the form of feeding frequency that is both good and effective. The purpose of this study was to examine and find the frequency of feeding on feed utilisation and growth of common carp fingerling fed with phytase addition. This research design used an experimental method, complete randomised design (CRD), 4 treatments with 3 replications, namely treatment A (frequency of feeding once a day), treatment B (frequency of feeding twice a day), treatment C (frequency of feeding three times a day) and treatment D (frequency of feeding four times a day). The test fish used were common carp fingerling with an average weight of 1.30 ± 0.12 g/head and a stocking density of 25 fish/head size (50x50x60) cm3 which were cultured for 56 days. The variables taken include Total Feed Consumption (TFC), Efficiency of Feed Utilization (EFU), Feed Conversion Ratio (FCR), Relative Growth Rate (RGR), Survival Rate (SR), and water quality. The results showed that different feeding frequencies had a significant effect on (P&lt;0.05) TKP, FCR, EPP, and RGR, but no significant effect on SR. The conclusion of this study was that the highest values for EPP and RGR variables were found in the frequency of feeding twice and four times a day. Keywords: feed, phytase, growth, efficiency

Effects of magnesium reduction in artificial low-salinity water on the growth of Pacific white shrimp Litopenaeus vannamei in a biofloc system

Crossovers in seedling relative growth rates between low and high irradiance: analyses and ecological potential

The effect of feeding frequency and feeding rate on growth of Oreochromis mossambicus fry was investigated over 30 d under temperature- and light-cycle-controlled conditions on the University of Zululand campus, South Africa, in October and November 2009. Weight gain, specific growth rate and gross food conversion ratio were significantly affected by feeding frequency, but survival rate was not significantly affected; the best results were obtained at a feeding frequency of four times per day. Feeding rate significantly affected weight gain and gross food conversion ratio, but not the specific growth rate or survival rate. Taking into consideration weight gain, specific growth rate and gross food conversion ratio, feeding four times per day at a rate of 15% body weight per day is optimal for fry growth.

The aim of this study was to evaluate the effect of supplementation with Chlorella vulgaris and molasses application rates on water quality, zootechnical performance, proximate composition and health status of Nile tilapia (Oreochromis niloticus) fingerlings cultivated in low-salinity (10 g L-1) biofloc systems. Four treatments were tested in a factorial design (supplemented with microalgae and molasses application rates): BFT-C30 (Biofloc supplemented with C. vulgaris and molasses application rates of 30% of the total daily feed); BFT-30 (Biofloc with molasses application rates of 30% of the total daily feed); BFT-C50 (Biofloc supplemented with C. vulgaris and molasses application rates of 50% of the total daily feed) and BFT-50 (Biofloc with molasses application rates of 50% of the total daily feed), for 70 days. Fingerlings of O. niloticus (initial mean weight of 3.15 ± 0.5 g) were stocked at a density of 680 fish m-3 in experimental units (50L), where 50% of this volume was biofloc previously matured. Throughout the experiment, they were supplemented with C. vulgaris every five days at the concentration of 5x104 cells mL-1. A significant interaction between supplementation with C. vulgaris and molasses application rates for final weight and length, survival, feed conversion ratio, specific growth rate, water consumption, protein efficiency ratio, sedimentation time, planktonic community and hematological indices were observed. The results indicated that the high molasses application rates (50%) in the biofloc system affects the zootechnical performance, water consumption, sedimentation time and the hematological indices of the Nile Tilapia fingerlings, hampering their development. Therefore, molasses application rates of 30% of the total daily feed for the tilapia fingerlings culture in low-salinity biofloc system is recommended.