The rapid expansion of global aquaculture has intensified demand for high quality dietary protein sources, while fishmeal supply has remained largely static for decades, leading to sustainability concerns, market volatility, and pressure on wild fisheries. Reducing fishmeal inclusion in aquafeeds is therefore a strategic priority, but such reductions often compromise feed palatability, nutrient digestibility, and growth performance. Functional protein ingredients derived from responsibly sourced byproducts represent a promising approach to maintaining animal performance while decreasing reliance on finite marine resources. Shrimp protein hydrolysate (SPH), produced from shrimp processing coproducts, has emerged as a potential solution due to its high digestibility, balanced peptide profile, and strong feeding‑stimulant properties.
This study evaluated the efficacy of SPH in supporting growth performance and feed utilization in Atlantic salmon (Salmo salar) fed low‑fishmeal diets. A 56‑day controlled feeding trial was conducted using three diets: a high fishmeal control containing 10% fishmeal (positive control); a reduced fishmeal control containing 5% fishmeal supplemented with feather meal hydrolysate; and a reduced fishmeal diet containing 5% fishmeal supplemented with 2.6% SPH. Each dietary treatment was fed to triplicate tanks, with 40 fish per tank, to ensure statistical robustness. Shrimp protein hydrolysate was produced through a fully engineered enzymatic hydrolysis process under optimized conditions, resulting in a high digestibility (>95%) ingredient that rich in short peptides and free amino acids.
At the end of the trial, salmon fed the SPH‑supplemented diet showed growth performance and feed efficiency comparable to those fed the high‑fishmeal control, despite a 50% reduction in fishmeal inclusion. Final weight gain in the SPH group reached 321 g, closely matching the 335 g observed in the positive control. In contrast, fish fed the reduced fishmeal control without SPH achieved only 291 g weight gain, representing a 10.4% reduction relative to the SPH treatment. Specific growth rate (SGR) followed a similar pattern, with the SPH group (1.32% day-1) performing on par with the high‑fishmeal control (1.36% day-1) and significantly outperforming the reduced‑fishmeal control (1.22% day-1). Feed conversion ratio (FCR) further confirmed improved feed utilization in the SPH group, which showed no statistical difference from the high‑fishmeal control, while the reduced fishmeal control exhibited a significantly higher FCR.
In conclusion, the use of SPH enables a 50% reduction in dietary fishmeal without compromising performance, while simultaneously supporting circular economy principles through the upcycling of shrimp processing byproducts. These findings highlight SPH as a scientifically validated and industry‑relevant ingredient for the development of sustainable, high‑performance aquafeeds.