The influence of napier grass biomass mixed feed on the biorefinery indicator for Nile tilapia production.

Aquaculture is vital for feeding a growing population as aquatic creatures require more protein. Utilizing protein-rich biomass for feeding animals is a possible solution. Biorefinery technology can extract protein and non-protein components from biomass, creating an economically feasible value chain. This study replaced fish feed with napier grass and used a compensatory response to reduce the cost of feeding Nile tilapia. The trial involved dividing mono-sex male Nile tilapia, initially weighing between 11.10 and 13.60 g/f, into four groups with three replications based on their feeding regime. Therefore, in the study, four groups of Nile tilapia were fed different diets for 90 days. The control group (T1) received a commercial floating pellet diet throughout the trial. Group T2 and T3 received a mix of commercial floating pellet diet and napier grass in varying proportions, and group T4 was fed with only napier grass throughout the trial. The study found that groups T2 and T3 had remarkable fish growth performance, high digestibility of napier grass, and lower feed prices with the highest benefit-cost ratios. The percentage of edible flesh and Hepatosomatic Index (PT2) were higher in group T2 than T3. Cellulase activity decreased with the frequency of napier grass intake, and the amylase activity was higher in T2 than T3, which also had the highest growth performance and feed utilization. Therefore, the study suggests that the optimal feeding regimen for Nile tilapia is T2 or T3, which promotes growth and is cost-effective.

Biorefining and biotechnology prospects of low-cost fish feed on Red tilapia production with different feeding regime.

This study aimed to decrease the production cost and increase tilapia yield with a feeding regime. The trial was divided into four treatments with three replications followed by the feeding frequency in monosex male Nile tilapia with an average initial weight of 17.86-18.40 g/fish cultured on a net cage in the earth pond for three months. Fish fed with 18% protein supplemented with 5% protein concentrate. The first month was used by 32% protein feed twice per day (T1, control), fish were fed twice per day every other week (T2), fish were fed twice per day per week (T3), and fish were fed twice per day per week (T3). Fish fed twice per day per week are now fed twice per day (T4). These results revealed that T2 fish had the highest growth performance and most protein consumption (P < 0.05). Moreover, fish in T2 has the lowest production cost and highest benefit-cost ratio (B/C ratio) (P < 0.05). The highest percentage of edible meat in T2 was P < 0.05, but the proximate analysis was close for all three groups (P > 0.05). As a result, it is necessary to ensure that Nile Tilapia culture has sufficient protein and nutrition control. This will allow for both high growth and low cost. Fish health and quality were positively affected by a perfect protein-containing feeding regimen. In fish fed with 18% protein and 5% protein concentrate for the first month, followed by 32% protein feed twice every other day and then with 18% protein.

Development of aeration devices and feeding frequencies for oxygen concentration improvement in 60-tones freshwater recirculating aquaculture and biofloc ponds of Asian seabass (Lates calcarifer) rearing.

This research aimed to improve the technique to maintain the oxygen content of two freshwater Asian sea bass (Lates calcarifer) culture systems (recirculating aquaculture system; RAS; and biofloc system; Floc). The dissolved oxygen content was increased by using a blower with flexible rubber hose aerators. For the first study, the effectiveness of oxygenation was investigated. As a result, the aerator and flexible rubber hose are appropriate for increasing oxygen levels in the fish pond. An air pump with a flexible aeration tube (400 W), one set of ejector aerators (250 W), and two sets of ejector aerators (250 × 2 W) were used to test the efficiency of oxygenation. In addition, the performance of the RAS and Floc systems, off-flavor (geosmin and MIB) in taints, and economic returns were assessed. This study found that after monitoring two 60-tonne concrete ponds with one set of blowers (RAS1) and two sets of blowers (RAS2) connected by a flexible rubber tube; feeding frequency (2 and 6 times/day). However, daily dissolved oxygen fluctuated in the RAS, and this value went to its lowest after post-feeding. Dissolved oxygen was higher than the two-meal pack per day when the feeding was expanded to six meals. This aeration device could provide dissolved oxygen enough for 900 kg fish/400 W. Seabass raised in the freshwater RAS system had higher yields and growth rates than those raised in the biofloc pond systems. In addition, low off-flavors trained was observed. Therefore, this research could improve aeration management by aeration devices and increase feeding frequency while developing freshwater-adapted Asian seabass production.

Effect of biogas sludge meal supplement in feed on growth performance molting period and production cost of giant freshwater prawn culture.

The worldwide prawn industry strives for better production and environmental sustainability. Shrimp feed is one of the most expensive aquaculture inputs; therefore, it must be cost-effective and environmentally safe. Fish meals in aquaculture are becoming unsustainable due to the cost and environmental concerns. The effects of a biogas sludge meal supplement in feed on freshwater prawn productivity were studied. This study aimed to examine the growth, survival rate, yield, feed conversion ratio, and molting period of giant freshwater prawns (Macrobrachium rosenbergii) fed with and without biogas sludge a low-cost resource. The four treatments were T1 (0% biogas sludge), T2 (10% biogas sludge), T3 (20% biogas sludge), and T4 (30% biogas sludge). Protein content ranged from 26.7 to 27.4% in the experimental diets. The experiment was conducted in 3 × 3x1.5 m cages in an earthen pond for 80 days. The data shows that freshwater prawn growth performance did not differ significantly across treatments (P > 0.05). Biogas sludge has been demonstrated to be a low-cost feed component for freshwater prawns. Regarding survival, productivity, and feed conversion ratio, T2 (10% biogas sludge) outperformed the other two. As a result of the research, it was determined that 10% of biogas sludge might be used as a low-cost freshwater prawn feed option. The molting period of freshwater prawns fed biogas-containing feed was investigated at various levels. Freshwater prawns grown in baskets in a pond at 32.2 °C for a trial period of 90 days were molted differently (P > 0.05). The molting periods for Tl, T2, T3, and T4 were 19, 18, 19.8, and 20.8, respectively. In addition, the research suggests efficient and long-term methods for supplying nutrient-dense prawn feed to aquaculture production systems.