Circular Valorization of Acid Silage from Invasive Pterygoplichthys Species in Hens Diets: Impacts on Laying Performance and Egg Quality

Pterygoplichthys species, an invasive fish, offers a sustainable protein alternative in poultry feed, aligning with circular economy goals and reducing environmental impact. This study aimed to assess the impact of incorporating various levels of acid silage derived from Pterygoplichthys species (ASP) into laying hen diets on productive performance and egg quality, as part of a biological waste valorization strategy aligned with circular economy principles. Sixty 35-week-old Rhode Island Red hens (BW 1932.1 ± 10.81 g) were randomly assigned to four isoproteic and isoenergetic dietary treatments containing 0%, 6%, 12%, and 18% ASP over 13 weeks. Productive, egg quality, and economic indicators were recorded weekly. The inclusion of 12% ASP resulted in the highest egg production (82.08%), egg mass (49.32 g/hen/day), and number of eggs per hen per week (5.6), along with improved feed conversion ratio (2.59) and the highest economic efficiency index (17.90%) and profitability, in comparison to the other treatments. Egg quality also improved with ASP, regardless of the inclusion level, particularly in egg weight (60.08 g), shell thickness (0.35 mm), and Haugh units (73.83), compared to the control group. Quadratic regression models identified optimal ASP inclusion levels ranging from 11.2% to 12.3%, depending on the variable analyzed. In conclusion, the inclusion of 12% ASP in laying hen diets represents an effective, profitable, and environmentally responsible nutritional strategy that aligns with the principles of the circular economy and sustainable food production.