UTILIZATION OF FREE OR DIPEPTIDE FORMS OF PHENYLALANINE IN DIETS FOR PACIFIC WHITE SHRIMP Litopenaeuse vannamei

Chorong Lee*, Soohwan Kim, Kyeong-Jun Lee
Department of Marine Life Science,
Jeju National University, Jeju 63243, South Korea
Corresponding author: kjlee@jejunu.ac.kr

Amino acids (AA) is not only the building blocks for protein synthesis but also have regulatory roles in key metabolic functions which are critical for maintenance, growth, immunity, larval metamorphosis, reproduction and resistance to pathogens in shrimp. Phenylalanine (Phe) is an aromatic AA and its requirement is influenced by dietary tyrosine level. Dietary Phe as an essential AA has great impacts on feed intake, growth performance, immunity and survival of fishes. However, few studies have been conducted to evaluate Phe requirement or availability in free or di-peptide forms for shrimp. A 4-week feeding trial was carried out to compare the efficacy of free Phe or dipeptide Phe-Ala in diets for white shrimp. Three diets were prepared with 1.4% supplementation of each free or dipeptide form of Phe in a basal diet (designated as F-1.4, D-1.4 and B-0.1, respectively). Two replicate groups of shrimp (initial body weight, 0.38 g) were fed one of the diets for 28 days. At the end of the feeding trial, growth performance was not significantly affected by the dietary treatments (Table 1). The highest survival rate was obtained in D-1.4 group which was significantly different from other dietary groups. The optimum dietary Phe level for juvenile L. vannamei was estimated to be less than 0.3% of dry diet based on growth performance results. The on-going experiment will be further addressed.