EFFECTS OF THREE KIND CU SOURCES ON GROWTH PERFORMANCE, ANTIOXIDANT ENZYMES AND INTESTINAL MORPHOLOGY OF JUVENILE PEARL GENTIAN GROUPER (EPINEPHELUS LANCELATUS♂×EPINEPHELUS FUSCOGUTTATUS♀)

This study evaluated the effects of dietary copper sulfate (CuSO₄), glycine chelated copper (Cu-Gly), copper hydroxymethionine (Cu-MHA) on growth, antioxidant enzymes and intestinal morphology of juvenile pearl gentian grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀). Juvenile pearl gentian grouper with the average body weight of (9.00±0.00) g were randomly divided into 3 groups with 3 replicates in each group and 30 fish in each replicate to feed isonitrogenous and isolipidic experimental diets with 3 different copper sources for 8 weeks. (1) The weight gain ratio (WGR), survival ratio (SR) in Cu-Gly and Cu-HMA groups were significantly higher than those in CuSO₄ group (P<0.05). (2) The hepatosomatic index (HSI) and viscerosomatic index (VSI) in Cu-HMA group was significantly higher than those in CuSO₄ and Cu-Gly groups (P<0.05). There was no significant difference in condition factor (CF) among all groups (P>0.05). (3) Cu contents of vertebrae in Cu-Gly and Cu-HMA groups were significantly higher than that in CuSO₄ group (P<0.05). (4) The serum concentrations of triglyceride (TG) and low-density lipoprotein cholesterot (LDLC) in CuSO₄ group was significantly higher than those in Cu-Gly and Cu-HMA groups (P<0.05). The serum concentration of high-density lipoproteot cholesterin (HDLC) in CuSO₄ group was significantly lower than that in Cu-Gly and Cu-HMA groups (P<0.05). (5) The activity of serum ceruloplasmin (CP) in CuSO₄ group was significantly higher than that in Cu-Gly and Cu-HMA groups (P<0.05). (6) The plica height (PH) of midgut and hindgut in Cu-HMA group were significantly higher than those in CuSO₄ and Cu-Gly groups (P<0.05). These results revealed that dietary adding Cu-Gly and Cu-HMA could improve intestinal morphology and serum lipid metabolism to ameliorate growth of juvenile pearl gentian grouper.