Intensive systems in aquaculture sectors induce stressful conditions and t herefore, finding functional feed additives that can counteract the negative performance is one of the the most important issues . Protected sodium butyrate (PSB) has multiple eff ects on the immune system and health status as well as on growth performance The present study aimed to assess the impact of the dose of a PSB on the zootechnical performance and resistance to challenge of Penaeus vannamei shrimp.
In this experiment 4 treatments were designed which only differ in the level of inclusion of the PSB (0, 2 , 4, and 8 kg/t of PSB . PSB was provided by Novation SL 2002 (Spain) with 54% sodium butyrate protected by a physical and chemical matrix of buffer salts. Each treatment was replicated 4 times, except for the Contro l which was replicated 8 times. A nimals were captured from 20% of the initial biomass for weighing and obtaining live weight data (g/shrimp), feed intake (g/shrimp), and feed conversion ratio(g/g). At the end of the experiment, a survival test, and acute nitrite toxicity test was conducted. A preliminary assessment was performed to determine the nitrite dose with minimal lethality and the time required to kill 80-90% of the animals based on exposure to the challenge (DL90). The data were subjected to analysis of variance (ANOVA).
Body weight was increased (P<0.05 ) as PSB dose increased at all ages estudied. Also , feed conversion ratio was impro ved as PSB dose increased at all ages estudied (P<0.05) . The sur vival during challenged with nitrite shown an reduction in shrimp fed with diets with PSB.
In conclusion , productive performance has improved linearly as the dose of PSB increased. Similar results have been observed in morbility and survival after nitrite challenge.