Also in crayfish: How phytase inclusion avoid phytic acid effects on hepatopancreas enzymes of redclaw Cherax quadricarinatus

CASSARETO M; AZCUY RL; STUMP L; LOPEZ GRECO L.S; COLOMBATTO D

AQUACULTURE RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023

1355-557X

Tis work aimed to evaluate the efects of dietary phytic acid on the enzymatic activities of the hepatopancreas of the redclawcrayfsh, Cherax quadricarinatus. For this purpose, a completely randomized in vitro trial was conducted with three phytic acidlevels (0.56, 1.68, and 2.80%) and three phytase doses (0, 250, and 500 PU/kg DM). Solubilized protein, reducing sugars, andsoluble phosphorus showed signifcant responses to the interaction between phytic acid and phytase (p < 0.001). Only the mainefects were detected on the released amino acids, in keeping with the main efects of alkaline protease activity, which arenegatively afected by phytic acid (p < 0.001) and improved by phytase inclusion (p < 0.001). Diferences in released reducingsugars were attributed to a reduction in amylase activity by increased levels of phytic acid and not to cellulase activity, where onlya negative trend of phytic acid was found (p � 0.068). Phytic acid depresses calcium availability, which would explain the decreasein amylase activity. A 500 PU/kg DM dose improved amino acid, reduced sugars, and phosphorus release. Tese in vitro resultsmight have in vivo implications for the digestibility of proteins, minerals, and energy. Further investigations are required todetermine the chelated calcium efect on redclaw amylase activity, molting, and survival.