Improving Heat Resistance of Nile Tilapia (Oreochromis niloticus) by Dietary Zinc Supplementation

Table 6

Changes in antioxidant biomarkers of Nile tilapia fed different concentrations (20 or 40 mg zinc/kg feed) and sources of dietary zinc for 45 days and postchallenge.

Heat stress (HS)	Groups	SOD (U/mL)	CAT (U/mL)	GPx (U/mL)	MDA (nmol/mL)
Before HS	CT	^c	^c	^c	^a
	20 ZnSO4	^c	^c	^bc	^b
	40 ZnSO4	^b	^ab	^ab	^b
	20 Thr-Zn	^b	^b	^abc	^b
	40 Thr-Zn	^a	^a	^a	^c
After HS	CT	^c	^b	^b	^a
	20 ZnSO4	^c	^b	^b	^b
	40 ZnSO4	^b	^a	^a	^b
	20 Thr-Zn	^b	^a	^a	^b
	40 Thr-Zn	^a	^a	^a	^c

Small superscript letters refer to differences for fish fed different levels and sources of zinc before or after HS in Duncan’s multiple range test, while asterisks indicate significant differences between values obtained before and after HS for each zinc treatment in -tests ().