Effects of Different Protein Hydrolysates on Growth Performance and Non-Specific Immunity of Japanese seabass (Lateolabrax japonicus)

Abstract:

This study was conducted to investigate the effects of four protein hydrolysates for replacing fish meal protein of basal diets on growth performance and non-specific immunity of Japanese seabass (Lateolabrax japonicus). The control group included fish meal (FM) as the single protein source. The experimental groups were replaced 10% of fish meal protein with four protein hydrolysates, including fish protein hydrolysate (FPH), pig blood protein hydrolysate (PBPH), soy protein hydrolysate (SPH) and yeast protein hydrolysate (YPH). Five diets were formulated to be isonitrogenous and isolipidic. All diets were fed in triplicate groups of L. japonicus (initial weight 31.99 g) for 8 weeks. Results indicated that the final body weight and specific growth rate (SGR) were significantly improved when fish were fed the FM and FPH groups compared with the PBPH, SPH, and YPH groups (P<0.05), but there was no significant effect on survival rate and feed intake among all groups (P>0.05). There was no difference in feed efficiency (FE) among the FPH, FM, PBPH, and YPH groups (P>0.05), while the FPH group was significantly higher than the SPH group (P<0.05). The FPH group had significantly higher protein efficiency ratio (PER) than other dietary treatments (P<0.05). The FPH, FM and YPH groups showed significantly higher protein productive value (PPV) than that of PBPH and SPH groups (P<0.05), while PPV in the FPH, FM and YPH groups were not significantly different (P>0.05). AKP, ACP, SOD, LZM activities and T-AOC in liver and serum of the FPH and YPH groups were significantly higher than other groups (P<0.05). The FPH group showed significantly highest crude protein of fish body in all dietary treatments, but there were no significant different between the FPH, FM and YPH groups (P>0.05). In conclusion, FPH had the best effects on growth and non-specific immunity of L. japonicus compared with other diets, followed by YPH, PBPH and SPH.