Effect of freshwater fish oil feed supplementation on the reproductive condition and production parameters of hybrid catfish (Pangasius larnaudii x Pangasianodon hypophthalmus, Sauvage, 1878) broodstock

Increased sales of freshwater catfish fillet in global markets is causing high demand for quality fingerlings to be used in aquaculture production. Due to limited freshwater catfish broodstock availability, the gap between fingerling supply and demand drives the continuous need for improvement of production chain, including increased fertility and fecundity of broodstock. Recent technological advances support the possibility to increase hybrid catfish (Pangasius larnaudii x Pangasianodon hypophthalmus) broodstock reproductive parameters by adding small amounts of freshwater fish oil (FFO) to their diet. Catfish broodstock were fed with three different levels of FFO feed supplementation (0%, 1%, and 2% FFO) during the spawning (April-August) and post-spawning (September-December) season. Significant differences in weight gain and average daily growth were observed in fish fed with 1% FFO supplemented diet. Biomarkers of reproductive status in females (17 β-estradiol /E₂; 1577 ± 5.26 pg/mL^-1) and males (testosterone /T; 3.28 ± 0.41 ng/mL^-1) fed with FFO supplements were significantly higher than the control (113.12 ± 43.33 pg/mL^-1 and 2.56 ± 0.95 ng/mL^-1), respectively). The oocytes and spermatocytes from fish fed with 1% and 2% FFO were in higher histological stages of maturity compared to control. Freshwater fish oil supplementation in fish feed during spawning season supported increased growth and enhanced reproduction indicators of hybrid catfish broodstock in aquaculture.