International Journal of Aquaculture 2015, Vol.5, No. 41, 1-20
13
Levels of ammonia decreased with phytase from
4.31±0.01mg/l in fish tank fed S1P0 to 1.05±0.01mg/l
in tank fed S1P3 (P<0.05). There were also significant
decrease in ammonia levels from 7.39±0.01mg/l for
fish fed S3P0 to 2.44±0.01mg/l in fish fed S3P4
(P<0.05). Fish fed diet S3P1 had the lowest (Duncan,
P<0.05) ammonia level (0.82±0.01mg/l) compared to
ammonia levels in tanks of fish fed S3P2
(1.45±0.01mg/l), S3P3 (2.05±0.01mg/l), and S3P4
(2.44±0.01mg/l). Concentration of ammonia decreased
significantly (Duncan, P<0.04) from 2.20±0.01g/l for
diet S4P0 to 0.76±0.01mg/l (S4P3). Ammonia
correlated negatively with treatment (r= -0.249,
P>0.05) and phytase (r= -0.105, P>0.05) (Table 13).
Levels of ammonia were significantly lower (Tukey,
P<0.05) in all phytase diets, irrespective of soyabean
Table 12 Effect of soya bean (full fat) and phytase on water quality of juvenile
Clarias gariepinus
Sources of
variation, P value
Dissolved
Oxygen (mg/l)
pH
Temperature (
0
C)
Ammonia (mg/l)
Nitrate (mg/l)
Phytase
0.000
0.162
0.000
0.000
0.000
Soya bean
0.000
0.007
0.270
0.000
0.000
Phytase
* Soya bean
0.000
0.159
0.002
0.000
0.000
Pooled SE
0.011
0.004
0.017
0.002
0.014
Tukey HSD
(means,
P values)
Phytase
P0 vs P1
-0.62*, 0.000
0.002, 0.999
-0.25*, 0.001
4.01*, 0.000
4.46*, 0.000
P0 vs P2
-0.65*, 0.000
0.023, 0.362
-0.46*, 0.000
2.15*, 0.000
3.91*, 0.000
P0 vs P3
-0.55*, 0.000
-0.002, 1.000
-0.95*, 0.000
3.05*, 0.000
12.22*, 0.00
P0 vs P4
-0.45*, 0.000
0.023, 0.362
-0.71*, 0.000
1.19*, 0.000
-5.59*, 0.000
P1 vs P2
-0.03, 0.953
0.02, 0.537
-0.21*, 0.008
-1.86*, 0.000
-0.56*, 0.000
P1 vs P3
0.08, 0.248
-0.01, 0.995
-0.70*, 0.000
-0.96*, 0.000
7.76*, 0.000
P1 vs P4
0.18*, 0.001
0.02, 0.537
-0.46*, 0.000
-2.82*, 0.000
-10.05*, 0.000
P2 vs P3
0.10, 0.068
-0.03, 0.323
-0.49*, 0.000
0.90*, 0.000
8.31*, 0.0000
P2 vs P4
0.20*, 0.000
0.00, 1.000
-0.25*, 0.002
-0.97*, 0.000
-9.50*, 0.000
P3 vs P4
0.10, 0.068
0.03, 0.323
0.24*, 0.003
-1.87*, 0.000
-17.81*, 0.000
Soya bean
S0 vs S1
-1.52*, 0.000
0.016, 0.923
-0.44*, 0.000
6.41*, 0.000
23.36*, 0.000
S0 vs S2
-1.30*, 0.000
0.022, 0.801
-0.41*, 0.001
4.71*, 0.000
10.45*, 0.000
S0 vs S3
-1.16*, 0.000
0.036, 0.39
-0.48*, 0.000
6.56*, 0.000
23.88*, 0.000
S0 vs S4
-1.10*, 0.000
-0.012, 0.973
-0.52*, 0.00
6.76*, 0.000
31.32*, 0.000
S1 vs S2
0.22*, 0.000
0.006, 0.984
0.03, 0.973
-1.70*, 0.000
-12.91*, 0.000
S1 vs S3
0.36*, 0.000
0.02, 0.430
-0.04, 0.927
0.15*, 0.000
0.52*, 0.000
S1 vs S4
0.42*, 0.000
-0.03, 0.143
-0.08, 0.509
0.35*, 0.000
7.96*, 0.000
S2 vs S3
0.14*, 0.002
0.01, 0.739
-0.07, 0.630
1.85*, 0.000
13.43*, 0.000
S2 vs S4
0.20, 0.000
-0.03, 0.051
-0.11, 0.214
2.05, 0.000
20.87, 0.000
S3 vs S4
0.06, 0.349
-0.05*, 0.003
-0.04, 0.927
0.20, 0.000
7.44, 0.000
Note: *The mean differences are significant at P<0.05
