Effects of Dietary Nucleotide Supplementation on Performance, Profitability, and Disease Resistance of Litopenaeus vannamei Cultured in Indonesia under Intensive Outdoor Pond Conditions

SIMPLE SUMMARY: In Indonesia, there is an increasing tendency to use vegetable protein sources as a replacement for fish meal in diets for Pacific white shrimp (PWS), Litopenaeus vannamei. This; however, involves a negative impact on shrimp health given the high content of anti-nutritional factors in such protein sources. As dietary nucleotides modulate the immune response, they might be able to counteract this effect by enhancing PWS immunity and improving their performance and resistance to diseases. In this study, we evaluated the effects of nucleotide supplementation in PWS receiving diets in which fish meal had been partially replaced with soybean meal. Our data show that dietary nucleotide supplementation leads to improved growth performance and profitability, as well as to higher resistance to Vibrio harveyi. These positive results indicate that dietary nucleotides could constitute a useful tool in the production of shrimp cultured under intensive open-pond systems. ABSTRACT: This study evaluated the effects of dietary nucleotide supplementation in Pacific white shrimp, Litopenaeus vannamei, cultured in Indonesia. A total of 22,500 shrimp receiving diets in which fish meal (FM) had been partially replaced with vegetable protein sources were classified into five study groups (4500 shrimp/group) and received different diets for 110 days: 10FM (control group; 10% FM), 6FM (6% FM—low FM and no nucleotide supplementation), 10FMN (10% FM; 0.1% nucleotides), 8FMN (8% FM; 0.1% nucleotides) and 6FMN (6% FM; 0.1% nucleotides). Growth performance, body composition, total hemocyte count (THC), lysozyme activity, and hepatopancreas histopathology were assessed. Organoleptic evaluation and profitability assessments were also performed. In addition, shrimp resistance to a Vibrio harveyi challenge was studied in shrimps after having received the diets for 30 days. Results showed that reducing FM had a negative impact on growth performance and hepatopancreas morphology. Adding nucleotides resulted in better performance and profitability, a healthier histomorphological appearance of the hepatopancreas, and significantly higher survival rates upon challenge with V. harveyi, while it did not negatively affect organoleptic parameters. In conclusion, nucleotide supplementation could be useful for optimizing performance, profitability, and disease resistance in shrimp cultured under intensive outdoor pond conditions.