Inclusion of two differently pH-autolysis hydrolysates of squid coproduct in diets of shrimp cultured under indoor and outdoor conditions

Abstract

Squid hydrolysates obtained by autolysis without addition of lactic acid at two different pH (5 and 7) and included at 25 and 50 g kg−1 in a commercial shrimp feed were evaluated. Shrimp fed on such diets were cultured under indoor and outdoor conditions. Diets containing both hydrolysates and included at both levels caused a higher feed consumption by shrimp. In general, shrimp fed on both hydrolysates, but particularly on that prepared at pH 7, exhibited similar or better production responses (survival, biomass, feed conversion ratio, specific growth rate) compared to those fed on diets without the inclusion of hydrolysates. Shrimp cultured outdoor showed a better growth performance compared to those cultured indoor. No significant differences were found regarding the proximate composition of shrimp of any treatment. Results suggest that the free amino acids provided by squid hydrolysates contributed to improve the feed consumption and growth performance of shrimp cultured under both indoor and outdoor conditions.