In vivo and In vitro Protein Digestibility of Formulated Feeds for Artemesia longinaris (Crustacea, Penaeidae)

This study was undertaken to determine the in vivo crude protein apparent digestibility in the prawn Artemesia longinaris, using feeds with 0.25% of chromic oxide and animal (fish meal, meat and bone meal and squid protein concentrate) and plant (soybean meal) ingredients. Three replicate groups of prawn were fed and the feces were collected. The rate of protein hydrolysis was measured in vitro using midgut gland enzyme extract from the prawns fed the respective feeds and was compared with those found with enzyme extract of wild prawn. The in vivo apparent digestibility coefficients showed significant differences among the feeds (P<0.05). Fish meal feed presented the highest digestibility (92%); intermediate digestibility (83%) was found for meat and bone meal feed, and the less digestible feed (63%) was that containing soybean meal and squid proteins concentrate. No significant differences in the in vitro protein digestibility were found among the experimental feeds. The results indicated the limitation of in vitro enzyme assays and that it should be complemented by in vivo studies.