Effect of hydrolyzed red worm ( Eisenia foétida) on production parameters in red tilapia ( Oreochromis sp.).

Background: Conventional fish feed based on fish meal, meat, and soy cake presents procurement difficulties and high costs, affecting the profitability and sustainability of the aquaculture industry.

Objective: To evaluate the effect of hydrolyzed red worm (HRW- Eisenia foétida) in red tilapia ( Oreochromis sp.) diet on production parameters.

Methods: The study was conducted at the aquaculture farm of the Politécnico Colombiano Jaime Isaza Cadavid (PCJIC) at 780 m.a.s.l.,with an average temperature of 28 °C. Ninety red tilapia fingerlings, averaging 7,5±0,5 g, were distributed in nine aquariums containing 75 liters of water. Fish underwentweight and size measurements at the beginning and end of the trial. They were fed experimental diets to apparent satiation three times daily. Water quality parameters and productive rates of growth and nutrient utilization were measured. The experimental design included three treatments with three replicates each: T1 (control diet, 0% hydrolysate inclusion), T2 (10% hydrolysate inclusion), and T3 (20% hydrolysate inclusion). ANOVA (p<0,05) was applied to growth and nutrient utilization variables, with mean comparisons using α<0,05 in SPSS version 25.

Results: Significant differences (p<0,04) were found between the control diet T1 (0% inclusion) and T2 (10% inclusion) in favor of weight gain (31,87 g). There were no statistical differences in size increase (p<0,217). As HRWinclusion increased, feed consumption decreased, likely due to higher hydrolyzed protein availability. Feed conversion rates showed significant differences (p<0,001) between T2 and T3 compared to T1, indicating better assimilation of the hydrolyzed protein. T2 and T3 also showed better protein and energy efficiency (p<0,001), demonstrating the hydrolyzed protein's nutritional quality and assimilation. Diet cost decreased with higher hydrolyzed inclusion (p<0,034).

Conclusion: Inclusion 10% and 20% hydrolyzed red worms significantly improved production parameters and reduced costs, making it a viable alternative for feeding red tilapia for small and medium-scale producers.