The Biological Activity Of Peptides And Their Effects On Growth Performance Of Tilapia

This paper studied the effects of lacto-bioactive peptides on the liver cells reproduction in vitro, the growth and non-special immune function of whole male in vivo through two feeding experiments.It was studied that effect of three kinds of bioactive peptides on the liver cells reproduction respectively in vitro test: the 1st product (Substrate: casein which was hydrolyzed by pancreatic proteinase and neutral proteinase); the 2nd product (Substrate: casein which was hydrolyzed by neutral proteinase and papain); the 3rd product (Substrate: casein which was hydrolyzed by pancreatic proteinase). According to different density, different bioactive peptides were added to serum or no serum culture mediums to culture the original generation primary liver cells for 48 h. The propagation was determined after 48 h.The results showed: The cell propagation of the 1st bioactive peptide product was significantly higher than the blank control group and casomorphin control group ( P<0.05); The cell propagation of the 2nd bioactive peptide product was slightly higher than the blank control group, and slightly lower than the casomorphin control group, but both had no significant difference ( P>0.05); The cell propagation of the 3rd bioactive peptide product was obviously lower than the blank control group and the casomorphin control group, the difference was significant ( P<0.05); There was significant difference in three kinds of bioactive peptide products (P<0.05); The results of propagation showed insignificant difference in the gradient test of the 1st bioactive peptide product ( P>0.05); The propagation tendency of liver cells varied similarly between the non-serum added group and serum added group.In the first feeding experiment, group A (the contral group)was fed with basal diet, group B, C, D, E, F was added 0.05%, 0.1%, 0.2%, 0.4%, 0.8% 2nd bioactive peptide product respectively. The experiment last for 8 weeks, and the growth performance and serum bio-chemical index were determined.It's shows: the special growth ratio of group F had significant improvement by 9.35% compared to the control group, while it's on significant difference in other groups (P>0.05); it's no significant difference of the feed efficiency ratio in all groups ( P>0.05); and hemolytic activity of the second pathway community (ACH50 unit) lysozyme activity had no significant difference in all groups ( P>0.05).In the second feeding experiment, the group I was fed with basal diet, group II,III,IV,V,VI were added 0.1%, 0.2%, 0.4%, 0.8%, 1.6% the 1st bioactive peptide...