Dietary acidifiers blend enhanced the production of Nile tilapia (Oreochromis niloticus), striped mullet (Mugil cephalus), and African catfish (Clarias gariepinus) polycultured in earthen ponds

Organic acids and/or their salts could be used as acidifiers to improve the performance, health, and immunity status of aquatic organisms. Generally, a single acidifier is used as a feed additive but the present study used a multiple acidifiers blend (Latibon (R)), which is a mixture of formic acid (25.7%), lactic acid (11.5%), and citric acid (7.0%). In the present study, each pond (3 acres) of nine earthen ponds was stocked with 15,000 Nile tilapia (NT; 2.1 +/- 0.2g), 3000 striped mullet (SM; 10.7 +/- 1.7g), and 300 African catfish (AC; 218.0 +/- 10.3g) representing a fish biomass of 10.5-11.5, 10.9-11.2, and 5.4-5.5kg/acre, respectively. Latibon (R) was incorporated to a floating diet at levels of 0.0 (control), 1.5, and 3.0g/kg diet. Fish fed one of the tested diets up to apparent satiation for a period of 20min thrice a day at 9:00, 12:00, and 16:00h for 28weeks. At the end of the feeding period, each pond was drained and fish of each cultured species were collected, counted, and group-weighed. No significant difference was observed in fish survival among the different treatments and its range was 92.1-93.4% for NT, 86.2-87.6% for SM, and 87.3-90.3% for AC. The production of NT, SM, and AC increased significantly as levels of Latibon (R) increased from 0.0 (828.9, 273.9, and 68.2kg/acre, respectively) to 3.0g/kg diet (1204.4, 304.3, and 77.8kg/acre, respectively). The total fish yield in the control ponds was 1171.0kg/acre, while it was maximized in ponds fed 3.0g/kg diet of Latibon (R) (1586.5kg/acre). This is because fish consumed more feed with increasing the levels of Latibon (R) from 0.0 (4614.0kg feed/pond) to 3.0g/kg diet (6256.0kg feed/pond) with insignificant differences in feed conversion ratios per ponds (1.34-1.35). Nile tilapia was the target fish; however, its production percentage to the total fish yield was 75.9%, whereas those of SM and AC were 19.2% and 4.9%, respectively, in ponds received 3.0g/kg of Latibon (R). Additionally, in this treatment, the sale of NT represented 62.8% of the total fish sale, whereas these of SM and AC were 34.1 and 3.1%, respectively. The simple economic analysis revealed that the net profit of ponds received 3.0g/kg diet of Latibon (R) increased by 23.3% over that received the control diet. Thus, the present study recommends the incorporating of 3.0g/kg diet of Latibon (R) to fish diets.