Effect of dietary vitamin B6on growth, feed utilization, health and non-specific immune of juvenile Pacific white shrimp,Litopenaeus vannamei

Abstract

Six diets were formulated with vitamin B6 levels (2.6, 32.7, 54.8, 90.7, 119.6 and 247.4 mg kg−1, dry diet) to determine the requirement for juvenile Pacific white shrimp, Litopenaeus vannamei. Triplicate groups of 40 juvenile shrimp (approximately 1.0 g) were provided four times each day to apparent satiation (8 weeks). Weight gain (WG), specific growth rate, feeding efficiency, protein efficiency ratio (PER) and protein productive value of the shrimp were significantly influenced by the vitamin B6 levels. No significant differences in whole-body and muscle composition, except for dry matter and protein contents in whole body. Vitamin B6 concentration in the hepatopancreas significantly increased with the dietary vitamin B6 level increasing from 2.6 to 32.7 mg kg−1. High-density lipoprotein cholesterol in the haemolymph improved with the dietary vitamin B6 levels increasing from 2.6 to 90.7 mg kg−1 diet and no significant differences in low-density lipoprotein cholesterol, cholesterol, glucose and total protein concentrations. Aspartate aminotransferase, alanine aminotransferase, superoxide dismutase, catalase and lysozyme in the haemolymph were significantly influenced by dietary vitamin B6 levels. The optimal dietary vitamin B6 requirements estimated using a two-slope broken-line model based on WG and SGR and an exponential model based on the vitamin B6 concentration in the hepatopancreas were 110.39, 110.08 and 167.5 mg kg−1, respectively.