Effects of dietary nucleotides on performance, proximate composition, health status, nitrogen stress resistance, and return on investment for Pacific white shrimp, Penaeus vannamei, raised in an intensive synbiotic system

Abstract

Shrimp production has adapted to recent disease outbreaks that have caused significant economic losses. Recognizing the importance of optimal shrimp nutrition is crucial for the sustainability of the industry. With increasing demand for high quality feeds that promote shrimp health, this study aimed to evaluate the effects of dietary nucleotide addition on performance, health status, nitrogen stress resistance, and ROI of Pacific white shrimp in an intensive synbiotic system. Experimental diets included a control group with no added nucleotides and diets with 75 mg kg⁻¹, 150 mg kg⁻¹, and 300 mg kg⁻¹. Shrimps, initially weighing 1.78 ± 0.02 g at a density of 100 shrimp m⁻², were randomly distributed and fed four times a day for 60 days. At the end of the trial, the nucleotide-addition diets had higher shrimp performance and protein composition than the control (p < 0.05). Notably, nucleotide supplementation improved gut morphology, evidenced by increased fold height, villus height, and enterocyte height. While Vibrio sp. and Bacillus sp. counts decreased across all treatments, yeast (fungi) showed an insignificant increase. Besides, no significant differences in survival rates, hemocyte counts, or gill histology were observed among treatments in ammonia and nitrite stress tests. Revenue generated from shrimp sales minus feed costs ranged from US$ 29,244 to US$ 30,542 ha⁻¹, with the N150 treatment exhibiting the highest return on investment. Consistently, nucleotide addition enhanced shrimp performance, protein composition, gut morphology, and return on investment. These results highlight the potential of nucleotide supplementation in optimizing shrimp feeding practices.