With their low molecular weight and high level of assimilation, mixes of free amino acids (MFAA) obtained from poultry keratin extensive hydrolysis are potential interesting candidates for aquaculture feeds dedicated to first development stages. In addition to previous results underlining MFAA positive effect on shrimp zootechnical performances, further investigations were conducted in partnership with Incabiotec/Concepto Azul, Tumbes, Peru, to evaluate potential of MFAA as new efficient solutions to improve immune response of white shrimp, L.vannamei, in case of bacteriological and viral challenges. Two trials, I and II, were conducted to evaluate the effects of MFAA on whiteleg shrimp Litopenaeus vannamei post larvae (PL). Both trials included a growth phase and experimental challenges. In these two trials, PL were fed four diets (control; control+1% MFAA; control+5% MFAA; control+10% MFAA) respectively for 28 days (trial I) and 21 days (trial II) for growth phases. Following this growth phases, animals were either experimentally infected with white spot syndrome virus (WSSV group) or Vibrio parahaemolyticus, with a toxin gene-bearing plasmid responsible for acute hepatopancreatic necrosis disease (AHPND group), or mock infected (non-infected control) considering four diets treatments (control; control+1% MFAA; control+5% MFAA; control+10% MFAA) during 28 days for trials I and II.
In these two trials, survival and biomass reached higher rates in WSSV infection groups, for PL fed with MFAA (Graph 1). For AHPND infection group in trial II, survival and biomass were also higher for PL fed with MFAA (Graph 2). Those results show the potential of MFAA to enhance shrimp PL performance and their application as shrimp feeding ingredients with functional benefits on animal survival in case of immune challenge.