The intensification in aquaculture production leads to increasing attention on the management of ammonia from its waste. Natural solutions such as Yucca schidigera extracts have shown beneficial effects on shrimps [1]. However, Y. schidigera is collected from the wild and its slow development make it an endangered natural resource that tends to be an expensive solution [2]. Alternative solutions, economically and environmentally improved, appear to be necessary to manage ammoniac. The aim of this study was to evaluate the effect of a dietary supplementation of a mixture of saponin-rich plants consisting of four saponin plants (Norponin Opti®, Nor-Feed) on the ammonia-nitrogen excretion of shrimps (Penaeus vannamei).
This study was performed in an experimental station (Halieutica, France). 138 juvenile shrimps were randomly divided into 2 groups with 3 replicates each: control groups (CTL), fed with a standard diet and supplemented groups (OPTI) fed with the standard diet supplemented with 500 g/T of the commercial blend of saponin-rich plants during 30 days. Measurement of TAN (NH4+/NH3) concentration in each group occurred once a day, 5 days a week using a colorimetric method assisted by a spectrophotometer. Individual performance measurements were made at the beginning and at the end of the experiment.
Results evidenced that OPTI group has a beneficial effect in reducing ammonia-nitrogen excretion during the whole experiment with an average difference of -13% and significantly (p<0,05) at week 3 of the experimentation with a difference of -20%. Weight gain during the experiment was not different significantly (CTL: 0.73 ± 0.15 g vs OPTI: 0.69 ± 0.15 g). Overall, the present study demonstrates that a supplementation with 500 ppm of the saponin-rich feed additive as positively impacting ammonia-nitrogen management.
References:
[1] Santacruz-Reyes RA, Chien Y-H. Bioresource Technology 2012; 113: 311–314.
[2] Arce-Montoya M, Hernández-González JA, Rodríguez-Álvarez M, et al. Plant Cell Tiss Organ Cult 2007; 88: 35–40.