Utilization of Raw, Dehullled, Autoclaved and Soaked Pea Pisum Sativum Seed Meals as Replacement for Fishmeal in Practical Diet Formulation for Juvenile Sea Bass in a Recirculating System

A 60-day feeding experiment on sea bass, Lates calcariform was conducted at the UPV Multi- Species Hatchery from September 23 - November 21, 2017. Healthy juveniles with an average initial weight of 0.09g were randomly stocked at twenty-five fish per tank at three replicates per treatment in fifteen 100-l conical tanks connected to a recirculating system under a photoperiod of 12h light and 12h dark. Five experimental diets were formulated to be isocaloric (40%) and isolipidic (10%) consisting of a Control Diet (without green pea); raw green pea, RGP (Diet 1); dehulled green pea, DGP (Diet 2); autoclaved green pea, AGP (Diet 3 ) and soaked green peas, SGP (Diet 4) to replace about 10-11% of the total protein in the diets. The percent weight gain (% WG) of sea bass fed control diet (1544±2.60%) was significantly (P<0.05) higher than diets with RGP, SGP and DGP, however fish fed AGP diets was not significantly different from those of the control group (P > 0.05). No significant difference (P>0.05) was found in the specific growth rate (%SGR) among the groups of fish fed control, AGP and DGP diets. Similarly, the SGR were not also markedly different for fish fed DGP and SGP diets, nevertheless the values were the lowest for the RGP diets. The best feed conversion ratio (FCR) and protein efficiency ratio (PER) were observed in sea bass fed control diet at 1.74 and 1.88 respectively. The highest survival rate at the end of the 60-day feeding period was observed for DGP diet (85.33%) which was comparable to those obtained with the other diets (AGP, SGP and Control), however the value was lowest for RGP diet (73.33%). Based on these results FM based diets with AGP and DGP have similar effects on the growth performance and survival of juvenile sea bass, L calcariform. It is quite clear that autoclaving and dehulling should be effectively used, not only for improving the nutritional quality of P. sativum, but also for reducing its antinutritional components as dietary protein source for sea bass.

Keywords: Green peas; Sea bass; Recirculating system; Dehulled peas; Growth