International Journal of Aquaculture, 2013, Vol.3, No.6, 23
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http://ija.sophiapublisher.com
24
protein supplement has been found to perform better
than a diet of fishmeal (Wu et al., 1995; Tudor et al., 1996).
Maize bran has a very high energy value and an
appreciable level of crude protein (Solomon et al., 2007).
Studies on the growth performance of
O. niloticus
fed on maize, rice and wheat brans in semi-intensive
earthen culture ponds have reported good growth
with maize and wheat bran but a poor growth
performance of fish fed with rice bran. The potential
use of maize bran as a growth promoter in fish has been
explored, with studies offering conflicting/inconsistent
results (Liti et al
.
2006).
Efforts are under way to
promote low-input production strategies for small-scale
fish farmers in Africa and to integrate aquaculture
production with other economic activities on the
farm. At present, the high cost and low quality of
fish feeds are major factors limiting the development
of aquaculture in Zimbabwe and are more likely to
remain challenging in the near future. A comparative
study to evaluate the effects of chicken manure
(14%
crude protein) and white maize bran (30%
crude protein) on the growth of
O.niloticus
was done
from 20 September 2011 to 20 February 2012.The
study was designed to provide information on the
most efficient and less expensive supplementary
feed for
O. niloticus
reared in pond culture.
1
Results
1.1
Physico-Chemical Parameters
Conductivity was found to be significantly high in
chicken manure fed pond compared to the maize
bran and the control pond (ANOVA, p<0.05) Figure
1.
There was however, no significant difference
between the chicken manure and maize bran fed
ponds. Chicken manure fed ponds had the highest
conductivity of (550 µm·S
-1
·
cm), followd by the control
(538
µm·S
-1
·
cm) and maize bran fed pond (521
µm·S
-1
·
cm). Total dissolved substances for maize
bran pond, chicken manure pond and the control
pond were significantly different (ANOVA, p<0.05).
Chicken manure had the highest total dissolved
substance with a recording of (239 mg/L), whilst the
control had (184 mg/L) and the least being the maize
bran which had a recording of (164 mg/L) which is
shown in Figure 2. Transparency (secchi disk reading)
for the maize bran, chicken manure and control was
significantly different (ANOVA, p<0.05). The
control pond had the highest secchi disk readings
from the start of the experiment to the end of the
experiment having (42 cm) as the highest reading.
Due to the different supplement application maize bran
and chicken manure had a lower transparency
compared to the control which ranged from 17 cm~27
cm, respectively(Figure 3)
.
Figure 1 Conductivity of the three ponds carried out in the
experiment
Figure 2 Total, dissolved substances readings done for maize
bran, chicken manure and the control pond
Figure 3 Secchi disk readings done for maize bran, chicken
manure and the control pond
1.2
Growth parameters
Growth rate increased significantly (ANOVA; p<0.05)
in both maize and chicken manure fed ponds. Fish
sampled from the maize bran fed ponds had the
highest percentage weight gain followed by fish sampled
from chicken manure fed pond and the control pond