Probiotics and Synbiotics in the Shrimp Nursery Phase: Higher Survival and Resistance to Nitrogen Compounds

This study evaluated the effects of commercial probiotics (Bacillus subtilis and Bacillus licheniformis) and synbiotics on the nursery rearing of Pacific white shrimp (Penaeus vannamei). Post-larvae (0.010 ± 0.001 g) were stocked at 5,000 PL/m³ across 16 experimental tanks (56 L) for 30 days under four treatments: Control (without probiotics or synbiotics), Probiotic (activated with demerara sugar), Synbiotic (fermented rice bran with probiotics), and alternating Probiotic + Synbiotic. Water quality parameters remained stable across all treatments. The supplementation of probiotics and synbiotics led to a significant increase in survival rates (>94% for probiotic, synbiotic, and combined treatments) compared to the control group (82.57 ± 2.81%). No significant differences were observed in final body weight, specific growth rate, feed conversion ratio (FCR), or productivity. Furthermore, when exposed to an acute 96-hour ammonia stress challenge (NH3-N up to 2.95 mg/L), shrimp previously reared with probiotics and/or synbiotics demonstrated significantly higher survival (92.5% to 96.5%) compared to the control group (85.0 ± 2.58%), confirming enhanced robustness and physiological resistance.