To evaluate the effects of replacing fishmeal (FM) with mixed plant proteins (corn gluten meal + soybean meal) supplemented with crystalline amino acids (CAAs) on the growth, health, and gut microbiota of carnivorous Micropterus salmoides ( M. salmoides ), an 8-week trial was conducted using fish with an initial body weight of (6.0 ± 0.5) g. Five isolipidic, isonitrogenous, and amino acid-balanced diets were formulated: a control (FM100%, 560.00 g/kg FM) and four test diets (FM75%, FM50%, FM25%, FM0%) with FM replaced by the mixed plant proteins. Growth performance (weight gain, WG; specific growth rate, SGR; feed conversion ratio, FCR; condition factor, CF; hepatosomatic index, HSI; survival rate, SR) and whole-body composition (moisture, crude protein, crude lipid, ash) did not differ significantly between FM75% and FM100% ( P > 0.05). However, FM substitution > 25% impaired growth and reduced ash content significantly ( P 25% ( P 25% were detrimental. • 25% FM replacement with mixed plant proteins + CAAs had no significant adverse effects on largemouth bass. • Levels of substitution above 25% are harmful to health of largemouth bass. • Replacing 25% fishmeal with mixed plant proteins plus CAAs is a viable dietary strategy for largemouth bass.
Feng et al. (Tue,) studied this question.