Evaluation of Yucca schidigera and Quillaja saponaria on Growth Parameters and Enzymes Activities of Juvenile Shrimp Litopenaeus vannamei Cultured in Low-Salinity Water

Abstract

The inclusion of Y u cc a sc h id i g e r a a n d Quil l aja saponari a e x tr ac ts (NTF) i n aquatic organisms display a posit i ve e f f e c t on production and organism’s physiology. F i f te e n tanks (14 0 - L) with low-salinity water (5‰) w e re st o c k e d with ten juvenile shrimp ( Litopenaeus vannamei, 2.6 g of mean weight ) feeding with 0, 0.250, 0.500, 1.0 or 2.0 g of N T F K g -1 of basal diet (tri pl i ca te treatment). The s h r i mp w e re cultured in a close recirculation system (control condition) and f e d ad l i bi t um d a i l y for 40 days. General growth parameters ( body weight, growth, body l e n g t h, feed conversion rate, survival, etc.) and hepatopancreatic digestive enzyme activities (alkaline protease, alkaline phosphatase, α-amylase, leucine aminopeptidase, and lipase) were evaluated after 40 days of shrimp culture. The final mean body weight, individual mean body, weight gain, and feed conversion ratio from shrimp feeding with 1.0 and 2.0 g of NTF Kg -1 have a significant ( P ) positive result compared to other experiments. The highest values of alkaline protease, lipase, and α - amylase were detected in shrimp feeding with 0.500 g of NTF Kg -1 , where a high level of leucine aminopeptidase and alkaline phosphatase were detected with 0.250 g of NTF Kg -1 treatment. However, any significant differences in enzyme activities were detected between the control group and treatments. The positive effect in shrimp growth and any negative effect in enzyme activity detected in present study suggest th a t NTF s hows p o te n tial a s a fee d a ddi t ive f or shrimp cultured at low-salinity.