Issue 03

Optimal feeding regimes for genetically improved farmed tilapia: ration effects on growth, survival, and water quality

2025-12-09T09:30:36Z

Optimal feeding regimes for genetically improved farmed tilapia: ration effects on growth, survival, and water quality Varathanathan, K.; Ganeshwaranathan, A.; Piratheepan, S.; Loganathan, T. The rapid expansion of tilapia aquaculture necessitates feeding strategies that enhance growth while minimizing environmental impacts. This study investigated the effects of three feeding rations 3%, 8%, and 12% of body weight per day on growth performance, feed utilization, survival, and water quality in Genetically Improved Farmed Tilapia (GIFT) fingerlings cultured in northern Sri Lanka. A total of 3000 fingerlings (initial mean weight: 30.62 ± 0.23 g) were randomly allocated into 12 cement tanks (37 m²; stocking density: 250 fish/tank) in a completely randomized design with four replicates per treatment. Fish were fed a commercial diet (30% crude protein) thrice daily over 56 days. Weekly measurements included growth parameters, feed conversion ratio (FCR), survival, and key water quality indicators. Significant differences (p <0.05) were observed in growth and FCR across treatments. The 8% ration produced the highest performance, with a final mean weight of 338.07 ± 12.4 g and length of 28.01 ± 0.8 cm, outperforming both the 3% (146.60 ± 8.2 g; 16.38 ± 0.5 cm) and 12% (332.27 ± 10.6 g; 27.85 ± 0.7 cm) rations. While the 3% ration had the best FCR (0.25 ± 0.02), its low growth made it economically unviable. The 8% ration achieved a balanced outcome (FCR: 0.43 ± 0.03). Survival rates were high (92–96%) with no significant variation among treatments. Water quality remained within acceptable limits, although higher rations elevated total ammonia nitrogen and total dissolved solids significantly (p <0.01). Overall, feeding GIFT fingerlings at 8% body weight/day offers optimal growth and efficiency without compromising water quality or survival. These findings support sustainable intensification of tilapia culture, particularly in resource-limited tropical regions. Further research should assess economic feasibility in larger-scale production systems.

Evaluation of sugarcane molasses as an alternative carbon source for in-vitro rooting of sour banana (mysore aab)

2025-12-09T09:09:21Z

Evaluation of sugarcane molasses as an alternative carbon source for in-vitro rooting of sour banana (mysore aab) Piyarathna, K.K.C.T.P.; Vassanthini, R.; Safeena, M.I.S.; Rohonadeera, H. Banana (Musa spp.) is one of the most important fruit crops globally, and in-vitro propagation plays a crucial role in large-scale multiplication, particularly for cultivars like sour bananas (Mysore AAB). In tissue culture, sucrose is the primary carbon source, typically used in the form of commercial white sugar. However, this study investigates the potential of sugarcane molasses as a cost-effective and sustainable alternative to commercial white sugar in Murashige and Skoog (MS) medium for in-vitro sour banana propagation. The experiments were conducted using MS medium supplemented with varying concentrations of sugarcane molasses (10 g/L, 20 g/L, 30 g/L, and 40 g/L) compared to the standard 30 g/L of commercial white sugar. Growth parameters such as root initiation, root number, root length, plant height, root fresh and dry weight, and total plant fresh and dry weight were evaluated over six weeks. The MS medium with sugar (T1) showed the best results, significantly outperforming all other treatments (p <0.05), with the highest plant height (53.36 mm), root number (5.41), root length (7.68 cm), and plant dry weight (0.09 g). Sugarcane molasses in low concentration with MS media (T2, 10 g/ L) exhibited promising performance, it significantly lower than T1 with plant height (34.4 mm), root number (4.4), and shoot dry weight (0.05 g). However, higher concentrations of molasses resulted in media browning and reduced root growth, likely due to excessive impurities and phenolic compound accumulation. This study demonstrates that sugarcane molasses in low concentrations with further optimization could be a viable, cost effective, and sustainable alternative carbon source for commercial micro propagation of banana. Therefore, further research is recommended to refine molasses treatment methods to minimize impurities and optimize plantlet development.

Economic analysis of banana production in Valikamam East ds division, Jaffna, Sri Lanka.

2025-12-05T10:01:57Z

Economic analysis of banana production in Valikamam East ds division, Jaffna, Sri Lanka. Thevasena, V.; Thivahary, G. Banana, an ancient fruit, has evolved into one of the world's most widely cultivated, traded, and consumed fruits. In the Jaffna district, particularly in the Valikamam East DS division, banana cultivation is a key livelihood activity of many households, supporting both income and food security. Despite its local significance, recent research focusing on the economic dynamics of banana production in this area remains limited. This study aims to fill this gap by conducting a comprehensive economic analysis of banana production in the Valikamam East DS division. The study employed a simple random sampling method with 100 banana farmers for primary data collection. SPSS software was used for data analysis. Results revealed that all farmers cultivated on their own land, with an average farmer age of 55.77 years and an average family size of 4.5 members. Despite major challenges like climate hazards and high labour costs, the annual average cost of production, return, and net profit stood at Rs 281,390, Rs 671,066, and Rs 389,676 per acre, respectively, indicating profitability with a benefit:cost (B:C) ratio of 2.38. A significant correlation was observed between the farmers’ experience, education and banana yield. Overall, this research provides valuable insights for banana farmers, policymakers, and researchers, paving the way for enhanced cultivation practices and informed decision-making.

Potential application of differently processed edible African palm weevil larvae (rhynchophorus phoenicis) as a fat replacer in sausage production

2025-12-05T09:19:10Z

Potential application of differently processed edible African palm weevil larvae (rhynchophorus phoenicis) as a fat replacer in sausage production Omojola, A.B.; Fadeyibi, B.T.; Awodoyin, O.R. Advocates for low-fat consumption have shifted focus to developing nutritious low-fat meat products from local, readily available raw materials. Edible African Palm Weevil Larvae (AFPWL) are a widely relished indigenous insect larvae whose properties are affected by processing methods. This study assessed the qualities of sausages produced with differently processed AFPWL. AFPWL, 65-80 days old (n=400), were asphyxiated at 4ºC and processed in three forms: Raw (AFPWL-R), Moist Cooked (AFPWL-MC) and Smoked (AFPWL-S) before use in sausage production. Four types of Sausages (S): AFPWL-RS, AFPWL-MCS, AFPWL-SS and Lard Sausage (LS) were produced. Swelling (%) and Water Absorption Capacities (WAC) (%) were determined on the emulsion. Product yield (PY%), moisture (%), crude protein (%), fat (%), and organoleptic characteristics (9-point hedonic scale) were determined on freshly cooked sausage. Thiobarbituric Acid Reactive Substances (TBARS) (MDAmg/100 g) were assessed over a pooled storage of 21 days. Data were subjected to ANOVA and a significant test using DMRT at Pα0.05. Swelling capacity 9.64 (AFPWL-MCS) and 9.33 (AFPWL-SS) are similar (P >0.05) but significantly higher (P <0.05) than 7.77 (LS) and 6.93 (AFPWL-RS), while WAC 32.00 (AFPWL-SS) is similar to 37.00 (AFPWL-MCS) and 26.00 (AFPWL-RS) but higher (P <0.05) than 23.00 (LS). All AFPWL sausages had higher PY (90.51-96.15) and Moisture contents (61.40-66.59). Crude protein (28.07) AFPWL-MCS and AFPWL SS (27.91) were higher (P <0.05) than LS (26.53) and AFPWL-RS (24.60). Fat (4.06) in AFPWL-RS was lower (P <0.05) than 4.24 (LS), 4.35 (AFPWL-SS) and 4.46 (AFPWL-MCS). All AFPWL sausages were significantly (P <0.05) tender, but AFPWL-SS sausage was the most acceptable. All AFPWL sausages had significantly higher TBAR values (0.53-0.58) when compared to 0.50 (LS). Processing of AFPPWL before use in sausage production could lead to a novel insect-based meat product with unique, high nutritional and sensory properties. .