Lyso-phospholipids (LPL) are obtained by enzymatic hydrolysis of phospholipids. This hydrolysis removes one fatty acid and renders the molecule more hydrophilic, giving LPL the ability to better emulsify and digest lipids. Aqualyso STD (AQLS) is a low-inclusion feed additive based on highly hydrolysed LPL and that aims to maximize lipid digestion and utilization of aquafeeds. The objective of this study was to evaluate the efficacy of AQLS to support the performance of Pangasius feeds with progressively reduced fat levels (i.e., oil inclusion).
A feeding trial was conducted at the Department of Aquaculture, IPB University, Indonesia. Juvenile Pangasius fish (12g/pc.) were stocked in 30 net cages (2 x 1 x 1.5m). Fish were fed six isoprotein and fishmeal-free feeds (n=5), for 62 days until they reached around 100g. The six experimental feeds are summarized in Table 1 and consisted of one control base feed with 31% CP and 7% fat (A), and then five feeds with 31% CP and fat levels between 6.5 and 5% and supplemented with AQLS (B, C, D, E and F). Fat levels were progressively reduced by reducing the inclusion of fish oil and palm oil. At the end of the trial fish were harvested and feed performance was evaluated.
Results (Fig. 1) showed that feed D, with 1.5% reduction in oil content and supplemented with 0.1% AQLS, generated significantly (p<0.05) better growth than the control feed A. Feeds B, C, and E, respectively with 0.5%, 1% and 2% lower oil inclusion and supplemented with 0.1% AQLS, resulted in numerically higher growth as compared with the control feed A. In this line, the supplementation of 0.1% AQLS under lower oil inclusion numerically improved feed conversion efficiency (FCR) consistently across feeds. These results open interesting cost-saving strategies for fish feed formulators.