Effect of plant protein concentrates on nutrition physiology of Litopenaeus vannamei (Boone, 1883) juveniles

This study was designed to test the effect of soy protein (SPC), wheat gluten (WHG) and potato protein (PPC), in vitro and in vivo digestibility of protein and energy in the juveniles Litopeneaus vannamei. A completely random design was used with nine 400-L tanks (with three repetitions by treatment). Ten respirometric chambers (500mL) were used for energy distribution. In vitro digestibility for SPC (8.8%) was higher than for PPC (5.8%) and for WHG (4.3%, P<0.05). Diets degree of hydrolysis ranged between 0.75% and 1.2%, with lowest value in potato protein concentrate diet (0.75 +/- 0.09%, P<0.05). No significant differences were obtained in apparent digestibility coefficient (ADC) for protein (63.474.1%). ADC for amino acids ranged between 80% and 90%. Daily growth coefficient ranged from 0.86% to 1.1% day-1, being the best in soybean protein concentrate diet (SPCd) (P<0.05). Significant differences on heat increment were observed (P<0.05); highest value was in wheat gluten diet (1.0 +/- 0.1kJ shrimp day-1) that coincided with a peak of trypsin specific activity (16.5 +/- 3.7mU mg similar to protein-1). Highest retained energy for growth was observed in shrimp fed SPCd (0.7 +/- 0.03kJday-1, P<0.05). Muscle collagen content presented a minimum of bands with SPCd, whereas shrimp post-mortem collagenase activity was not affected by any of the three diets (P>0.05).