EFFECTS OF DIETARY POTASSIUM DIFORMATE ON JUVENILE TILAPIA IN COLOMBIA - A CASE STUDY  

Global production of farmed tilapia in more than 140 countries exceeded 5.5 million t in 2015, an increase of more than 19 percent in only two years. This tremendous growth in production requires high-quality fish feeds. In particular, new, antibiotic-free and sustainable feed additives which support this production growth have caught the attention of the aquaculture industry. Dietary organic acids, and especially potassium diformate - the most widely tested organic acid salt in aquaculture, are among the various alternatives spearheading environmentally friendly and nutritionally-sustainable aquaculture approaches.

Dietary potassium diformate (KDF) has been used in tilapia aquaculture since 2005, to improve the performance and survival of the fish. Trials had mainly been carried out in Asia, Africa and Europe. However, data from Latin America had not yet been evaluated. This study analysed the impact of the additive on juvenile Red Tilapia in pond culture in Colombia.

A trial was carried out in a commercial pond farm for Red Tilapia in Huila, Colombia. Six ponds were used for the study. Three ponds served as a negative control, whereas fish in the other ponds were fed a commercial diet which included 0.2% potassium diformate. Almost 181,000 fish were used for the study. The duration of the trial was at least 164 days. Results for weight gain, FCR, mortality and the Fish Productivity Index are expressed as mean ± standard deviation. Data were subjected to statistical analysis and a significance level of 0.05 was used in all tests.

Tilapia fed with 0.2% KDF had a numerically increased weight gain (309 g vs. 325 g for control and treatment respectively, +5.2%, P=0.11) within a culture period, which was 9 days shorter than the control (164 vs. 173 days). Furthermore, the feed conversion ratio of fish fed KDF was also improved (-5.0%). Due to the low number of replicates and the high variation between ponds, this result was non-significant. Finally, the fish productivity index, which is calculated on the basis of weight gain, survival rate and feed conversion - thus combining the three most important parameters in any fish production, improved impressively, by almost 13%. Based on the data listed above, the cost of weight gain in fish mass was reduced by more than 3 USD cents per kg.

Under commercial conditions, results show improved growth and FCR in tilapia fed with dietary potassium diformate, leading to an increased overall productivity. The use of KDF in tilapia feed under farm conditions in Colombia is therefore supported as a promising and cost-effective tool for the modern aqua-feed industry in order to contribute to ecologically sustainable tilapia production.