Optimum dietary level of Chlorella vulgaris powder as a feed additive for some blood parameters and digestive enzymatic activities of grey mullet, Mugil cephalus

Abstract

The present paper aims to shed lights on effect of optimum dietary level of Chlorella vulgaris powder (CP) as a feed additive on some blood biochemical parameters (Cholesterol (CHO), triglyceride (TG), total protein (TP), glucose (GLU), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and lysozyme) and digestive enzymatic activities (amylase, lipase and protease) of the grey mullet (Mugil cephalus L). Four experimental diets were supplemented with CP at 0, 5, 10 and 15 g kg−1diet (CP0, CP, CP10 and CP15). Number of twelve tanks (60-L) with three replicates for treatment group (n=10 per tank with average initial weights 14.95 ± 2.01 g) and the control group were considered. After 60 days of the feeding trial, fish fed CP5 diet had lower serum CHO and TG levels than did fish fed CP0, CP10 and CP15 diets (P<0.05). There was no significant difference in GLU between fish fed CP5 and CP10 diet (P>0.05). The highest serum total protein, amylase, protease, lipase and lysozyme activities were observed in fish fed CP5. Also, fish fed CP10 and CP15 diets had higher digestive enzymatic activities, serum total protein and lysozyme activities than did fish fed CP0 (P<0.05). These results indicate that dietary supplementation of 5 g chlorella powder in the commercial diets could improve the blood chemical responses and the activity of digestive enzyme in grey mullet.