Effect of γ‐aminobutyric acid supplementation on growth performance, endocrine hormone and stress tolerance of juvenile Pacific white shrimp, Litopenaeus vannamei, fed low fishmeal diet

An 8‐week feeding trial was conducted to evaluate the optimum dietary γ‐aminobutyric acid (GABA) level in low fishmeal diet for juvenile Pacific white shrimp, Litopenaeus vannamei. Six practical diets (449 g kg−1 protein, 87 g kg−1 lipid) supplemented with graded levels of GABA (0, 50, 100, 150, 200, 250 mg kg−1) were formulated. Each diet was randomly assigned to triplicate groups of 30 shrimps (approximately 0.44 g), and the shrimps were fed four times a day to apparent satiation. Weight gain and gain rate were significantly increased with the supplementation of GABA (P