Effects of Replacing Fishmeal With Soybean Meal and Peanut Meal in Low‐Protein Diets on Production Traits and Nutrient Composition of Penaeus vannamei

Finding sustainable ingredients to replace fishmeal in shrimp feed is crucial for the aquaculture industry. This study evaluated the replacement of fishmeal with a combination of soybean meal and peanut meal in low‐protein (35%) diets for Pacific white shrimp, Penaeus vannamei . Five experimental diets were formulated: one high‐fishmeal, high‐protein control diet (fishmeal 20%, crude protein 40%; FMC) and four low‐protein diets containing 20% (FM20), 15% (FM15), 10% (FM10), and 5% (FM5) fishmeal, representing replacement levels of 0%, 25%, 50%, and 75%, respectively. Survival exceeded 95% across all treatments, with no significant differences ( p = 0.278). Weight gain (WG), WG rate (WGR), and feed efficiency (FE) in the FM5 group (75% fishmeal replacement) were significantly lower than in all other groups ( p < 0.05). No significant differences were detected for meat yield (MY) among all groups ( p = 0.092). Nutritional analysis showed the FM5 diet resulted in compromised nutritional quality, including altered amino acid profiles and significantly reduced crude fat content and n‐3 polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), leading to an unfavorable n‐3/n‐6 ratio. The study demonstrates that replacing up to 50% of fishmeal with a combination of soybean meal and peanut meal in a 35% protein diet maintains production performance in P. vannamei . However, 75% replacement negatively impacts growth, feed utilization, and product quality. The findings underscore that the protein source is more critical than the dietary protein level itself and highlight the importance of a balanced inclusion of animal and plant proteins for sustainable shrimp feed formulation.