Effect of Stocking Density and Dietary Protein Level in Biofloc System on the Growth, Digestive and Antioxidant Enzyme Activities, Health, and Resistance to Acute Crowding Stress in Juvenile Common Carp (Cyprinus carpio)

Table 5

Digestive enzyme activities in the digestive tract and antioxidant enzyme activities in the liver of common carp reared in medium (MD) and high (HD) densities and fed 35 and 25% dietary protein in a biofloc system and control (clear water, medium density, 35% dietary protein) for 60 days ().

Parameters	Experimental groups					Two-way ANOVA
	Control	MD35	MD25	HD35	HD25	Density	Protein	Interaction
Amylase (U mg^−1 protein)	^c	^ab	^a	^b	^b		NS	NS
Lipase (U mg^−1 protein)	^d	^a	^b	^b	^c			NS
Protease (U mg^−1 protein)	^c	^a	^a	^ab	^b		NS	NS
SOD (U mg^−1 protein)	^c	^a	^ab	^b	^b		NS	NS
GPx (U mg^−1 protein)	^c	^a	^ab	^a	^b	NS		NS
Catalase (U mg^−1 protein)	^b	^a	^a	^a	^b	NS		NS
MDA (nmol mg^-1 protein)	^a	^c	^c	^b	^a
TAOC (nmol mg^-1 protein)	^b	^a	^a	^b	^c

Means in the same row with different superscripts are significantly different (). SOD: superoxide dismutase; GPx: glutathione peroxidase; MDA: malondialdehyde; TAOC: total antioxidant capacity; NS: not significant ().