Dietary shrimp by‐product meal as a fishmeal replacement: Effects on growth performance and acute stress responses in juvenile Pacific white shrimp ( Penaeus vannamei )

Abstract Sustainable aquafeed development requires alternative protein sources that reduce dependence on fishmeal without compromising shrimp performance. This study evaluated shrimp by‐product meal (SBM) as a fishmeal replacer in juvenile Pacific white shrimp ( Penaeus vannamei ) and assessed their responses to acute air exposure stress. Six isonitrogenous and isolipidic diets were formulated with SBM inclusion levels of 0%, 5.04%, 10.08%, 15.12%, 20.16%, and 25.20%, designated SBM0, SBM20, SBM40, SBM60, SBM80, and SBM100, respectively. These inclusion levels corresponded to 0%, 20%, 40%, 60%, 80%, and 100% replacement of dietary fishmeal, respectively. A total of 450 shrimp with an initial body weight of 3.11 ± 0.02 g were fed the experimental diets for 6 weeks and subsequently subjected to 20 min of air exposure. Fishmeal replacement with SBM up to 40% did not compromise growth performance, whereas replacement levels of 60%–100% resulted in reduced weight gain and specific growth rate. Survival was higher in most SBM‐fed groups, while whole‐body proximate composition, amino acid profile, and fatty acid composition were unaffected. No significant interaction between dietary SBM level and air exposure was observed for plasma metabolites, ionic parameters, or selected hepatopancreatic gene‐expression responses. Air exposure increased plasma transaminases, glucose, circulating lipids, and major ions and reduced gpx expression. Overall, SBM replaced up to 40% of dietary fishmeal without impairing growth performance and did not exacerbate the measured responses to acute air exposure under the present experimental conditions.