Effects of Dietary Protein-to-Energy Ratios on Growth, Immune Response, Antioxidative Capacity, Liver and Intestinal Histology, and Growth-Related Gene Expression in Hybrid Yellow Catfish (Pelteobagrus fulvidraco × Pelteobagrus vachelli )

Table 7

The gut micromorphology of hybrid yellow catfish fed different dietary P/E ratio for 7 weeks.

P/E ratio mg/kcal

Foregut (μm)

Midgut (μm)

Hindgut (μm)

hV^1

wV^2

hE^3

M^4

S^5

hV

wV

hE

M

S

hV

wV

hE

M

S

84

^ab

^a

^c

^a

^ab

^b

^ab

^ab

^ab

^ab

^a

^ab

^ab

^a

^ab

88

^ab

^ab

^c

^ab

^ab

^bc

^abc

^ab

^a

^ab

^bc

^ab

^abc

^ab

^ab

90

^b

^bc

^c

^a

^b

^bc

^a

^a

^b

^ab

^bc

^bc

^a

^ab

^ab

93

^c

^c

^d

^bc

^ab

^cd

^bc

^ab

^bc

^bc

^cd

^bc

^cd

^bc

^c

95

^d

^c

^d

^c

^b

^d

^d

^b

^b

^c

^d

^c

^d

^c

^c

96

^ab

^a

^ab

^a

^ab

^bc

^ab

^ab

^a

^ab

^bc

^ab

^bcd

^ab

^ab

99

^b

^ab

^a

^a

^ab

^b

^abc

^ab

^a

^a

^b

^ab

^a

^abc

^b

103

^a

^a

^bc

^a

^a

^a

^ab

^a

^a

^a

^a

^a

^abc

^a

^a

Values are of three replications. Values in the same line with superscripts are significantly different. hV¹: villus height; wV²: villus width; hE³: enterocytes height; M⁴: muscular layer thickness; S⁵:serosa thickness.