Post larvae shrimp are usually transported in plastic bags over long distances. During transport, the stress applied to the shrimp causes a metabolic change resulting in a decrease of water quality and an increase of ammonia, which can influence the physical condition of the post larvae shrimp and lead to increased mortality. These diminished conditions are often mistakenly considered by farmers as a weakness of the alevins.
The aim of this study was to evaluate the effect of addition of Yucca schidegera (Norponin® L, Nor-Feed, France) on the ammonia-nitrogen excretion of shrimps post larvae (Penaeus vannamei) during packing.
This study was performed in an experimental station (Indonesia). Shrimps post larvae were randomly divided into 3 groups contained 3,480 post larvae in bag of 5 L: one control groups (CTL) with 2.5 g of active carbon, (YUCCA25) with 25 ppm of Yucca, (YUCCA50) with 50 ppm of Yucca and (YUCCA100) with 100 ppm of Yucca. Each group are performed in triplicate with a storage of 12 hours similar to the packing process. Measurement of TAN (NH4+/NH3) concentration occurred at the end of the storage. Mortality was assessed at the end of storage for each group.
Results evidenced that YUCCA groups have a beneficial effect in reducing significantly ammonia-nitrogen excretion after storage with a difference of -37% for YUCCA25, -85% for YUCCA50 and -92% for YUCCA100 compared to the CTL group. Mortality after storage was not significantly different for each group (CTL: 2.46 ± 0.69%, YUCCA25: 3.41 ± 0.93%, YUCCA50: 3.25 ± 0.64% and YUCCA100 3.92 ± 0.91%).
Overall, the present study demonstrates that an addition from 25 ppm of Yucca schidigera can reduce ammonia nitrogen excretion and potentially maintain conditions of alevins during storage. However, other studies are necessary to assess zootechnic parameters of shrimps post larvae after storage with Yucca schidigera.