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 9
Dietary effects on growth, feed conversion, protein and lipid utilization, and body condition parameters in rainbow trout (N = 4).
Rainbow trout fed with
value
Dried duckweed (DWD)
Fermented duckweed (DWF)
Control
DWD12
DWD24
DWD35
DWF12
DWF24
DWF35
SEM
DWD
DWF
IBW (g)
1.47
1.51
1.47
1.47
1.53
1.48
1.48
0.009
—
—
FBW (g)
6.81
6.99
6.35
5.81
6.93
6.41
6.22
0.097
0.001
0.033
WG (g)
5.35
5.48
4.88
4.34
5.41
4.93
4.74
0.092
0.001
0.023
PWG (%)
364
377
333
296
373
337
324
6.61
<0.001
0.033
SGR (% day−1)
4.39
4.37
4.17
3.93
4.33
4.18
4.10
0.037
<0.001
0.012
FCR (g·g−1)
1.11
1.11
1.16
1.26
1.12
1.19
1.20
0.012
<0.001
0.023
PPV (%)
21.4
21.5
20.4
18.8
21.2
20.0
19.8
0.22
<0.001
0.016
LPV (%)
23.7
23.8
22.8
21.3
23.5
22.4
22.3
0.20
<0.001
0.020
K
1.27
1.23
1.24
1.18
1.25
1.27
1.20
0.011
0.051
0.277
ISI (%)
16.0
16.0
15.9
16.4
16.6
16.7
17.7
0.16
0.578
0.008
HSI (%)
2.43
2.42
2.42
2.31
2.53
2.55
2.60
0.035
0.595
0.162
Visceral fat (%)
66.7
58.3
50.0
47.9
60.4
52.1
47.9
1.84
0.003
0.004
Survival (%)
100
100
100
95.0
100
100
96.7
0.60
0.058
0.391
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.
