Fungal proteins are emerging ingredients having high potential for use in aquafeeds, yet digestibility and practical inclusion limits remain unclear for marine shrimp. This study evaluated a filamentous fungus ( Paecilomyces variotii PV ) produced from corn ethanol thin stillage as a replacement for salmon by‐product meal (SLM) and poultry by‐product meal (PBM) in diets for juvenile Penaeus vannamei . Five diets were formulated by replacing SLM and PBM with PV (0%–100% replacement; PV from 0% to 22.60% of the diet). After 78 days, shrimp performance was similar across treatments. Survival remained high (95.6 ± 3.4%). Weekly growth averaged 1.04 ± 0.08 g/week, with a gained yield of 1168 ± 92 g/m 2 . Apparent feed intake (AFI) was 14.6 ± 0.6 g/shrimp, and feed conversion ratio (FCR) was 1.33 ± 0.09. Final body weight (BW) differed statistically among dietary treatments, with shrimp fed the diet containing 22.60% PV exhibiting a reduction (12.31 ± 1.89 g) compared with 0% PV (12.80 ± 2.02 g). In a digestibility assay (substitution method; 30% test ingredient), ingredient‐level crude protein (CP) apparent digestibility coefficient (ADC) was higher for SLM (72.02 ± 1.96%) than for the PV (62.28 ± 0.48%). Amino acid (AA) digestibility was consistently lower for PV, with marked reductions in methionine (Met) (73.21 ± 1.72% vs. 85.71 ± 1.05%) and lysine (Lys) (86.23 ± 0.66% vs. 89.35 ± 1.10%) compared with SLM. Whole‐body proximate composition at harvest was largely unaffected by dietary treatment, whereas nutrient and energy retention differed, with the highest protein retention observed at 75% replacement and reduced lipid and energy retention at 100% replacement. Overall, results indicated that PV can replace up to 75% of SLM and PBM, corresponding to 16.95% dietary inclusion, in diets for P. vannamei without impairing growth performance, whereas complete replacement (22.60% PV) reduces nutrient utilization efficiency and final BW.
Nunes et al. (Thu,) studied this question.