Prebiotic evaluation of copra-derived mannooligosaccharides in White-leg shrimps

Abstract

β-Mannooligosaccharides, produced by partial enzymatic hydrolysis of copra pulp residues using recombinant A. niger β-mannanase, were evaluated for its potential use as a prebiotic feed supplement for L. vannamei culture. Results observed in a 30-day feeding trial showed that dietary supplementation of copra-derived MOS, with doses varying from 4 to 10 g kg-1 of dried feed, increased the number of intestinal Lactobacilli and Bifdobacteria in shrimps fed copra-MOS supplemented diets increased approximately from 150-300%. The number of intestinal presumptive Vibrio, Coliforms, Clostridia and Salmonella reduced to 39.6-54.1%, 56.9-65.9%, 71.8-86.1% and 100-100%, respectively. In addition, copra-MOS supplement in the feed led to an enhancement of the weight gain, specifc growth rate, feed conversion ratio and feed intake of shrimps (P<0.05). After a 7-day challenging test with Vibrio harveyi pathogen (~106 CFU mL-1) by immersion, the cumulative mortality of the shrimps fed with the diet supplemented 10 g kg-1 copra-MOS was 3.5%, that obviously decreased compared to the control shrimps (29.5% mortality). Taking advantage of its intestinal microfora modulation towards increasing probiotic-like bacteria and Vibriosis resistance, this cheap oligosaccharide will be valuable in various aquatic animal farming. © 2013 Cuong DB, et al.