Partial Replacement of Fishmeal with Duckweed (Spirodela polyrhiza) in Feed for Two Carnivorous Fish Species, Eurasian Perch (Perca fluviatilis) and Rainbow Trout (Oncorhynchus mykiss)
Table 7
Dietary effects on growth, feed conversion, protein and lipid utilization, and body condition parameters in Eurasian perch. Values are averages of four replicates.
Perch fed with
p value
Dried duckweed (DWD)
Fermented duckweed (DWF)
Control
DWD12
DWD24
DWD35
DWF12
DWF24
DWF35
SEM
DWD
DWF
IBW (g)
3.53
3.46
3.55
3.51
3.50
3.51
3.55
0.02
—
—
FBW (g)
7.30
6.45
6.05
5.20
6.25
5.69
4.68
0.18
<0.001
<0.001
WG (g)
3.76
2.99
2.50
1.69
2.75
2.18
1.13
0.17
<0.001
<0.001
PWG (%)
111
86.5
75.0
50.2
80.6
64.4
35.4
5.09
<0.001
<0.001
SGR (% day−1)
2.13
1.78
1.59
1.16
1.68
1.39
0.86
0.09
<0.001
<0.001
FCR (g·g−1)
1.53
1.79
2.10
2.88
1.86
2.42
4.60
0.24
0.011
0.011
PPV (%)
20.0
16.7
12.9
11.5
15.3
11.4
6.03
0.88
<0.001
0.010
LPV (%)
11.7
1.91
5.16a
−8.17
−1.45
−0.63
−9.13
1.36
0.033
<0.001
K
1.57
1.51
1.54
1.46
1.52
1.41
1.45
0.02
0.843
0.019
ISI (%)
7.67
7.55
8.12
7.70
8.10
6.92
8.13
0.12
0.575
0.691
HSI (%)
1.42
1.40
1.33
1.40
1.32
1.27
1.50
0.03
0.550
0.036
Visceral fat (%)
46.9
25.0
25.0
21.9
25.0
33.3
25.0
2.67
0.026
0.460
Survival (%)
93.8
93.8
85.0
92.5
95.0
92.5
78.8
1.86
0.422
0.023
IBW: initial body weight; FBW: final body weight; WG: weight gain; PWG: percentage weight gain; SGR: specific growth rate; FCR: feed conversion ratio; PPV: protein productive value; LPV: lipid productive value; K: condition factor; ISI: intestinal-somatic index; HSI: hepatosomatic index.
