ORGANIC ACID (Amasil® NA) IMPROVES THE PERFORMANCE OF RED TILAPIA Oreochromis sp. AT FARM LEVEL

Formic acid is known to improve growth performance and prevention of disease in fish by reducing the pathogen load in feed and in animal gut. A cross country farm level experiment was conducted in Vietnam to evaluate the efficacy of Amasil^® NA (buffered formic acid) on growth performance and prevention of diseases caused by and bacteria in red tilapia (Oreochromis sp.). This experiment was conducted in three provinces in Mekong Delta, Vietnam from 10^th July 2016 to 08^th June 2017. Twelve floating cages were used for the experiment in three sites, each site has four floating cages, which were divided into two groups: 1. control group (C) was fed on commercial fish feed and 2. treatment group (T) was fed with commercial fish feed supplemented with 3kg/ton of Amasil^® NA. Three provenances viz. Vinh Long stocked 28,000 & 50,000 fish each in control and treatment; Ben Tre stocked 39,956 & 39,966 fish each in control and treatment, An Giang stocked 31,000 & 29,000 fish each in control and treatment.

The results clearly demonstrated that Amasil® NA at 0.3% in feed had an overall positive effect on the fish weight gain and final fish weight (Table 1).

Amasil^® NA 0.3% application significantly lowered FCR compared to the Control (1.78 ± 0.35 vs. 2.26 ± 0.66) in An Giang province. . Survival rates were numerically higher in Amasil NA supplemented group than control in Vinh Long and An Giang provinces. The total aerobic bacterial population in liver, kidney, and spleen of the experimental fish were significantly lower in Amasil^® NA group than in the control due to the fish affected by the harmful bacteria as Streptococcus and Aeromonas (p<0.05).

In conclusion, under practical field condition supplementation of fish diet with Amasil NA at 3kg / ton could improve the growth performance and reduce the pathogen load in red tilapia.