International Journal of Aquaculture 2015, Vol.5, No. 35, 1-6
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Development Centre (NARDC), two commercially
produced aqua feeds, namely: Namfeed (Diet 2) and
Tiger Animal Feed (Diet 3) were administered to
Oreochromis niloticus
, a native species to central and
North Africa and the Middle East (Boyd, 2004), in
order to ascertain which feed was best for their
survival and growth. According to FAO (1990),
O.
niloticus
was considered a good candidate for
aquaculture because it grew faster to good market size,
especially the male fish. This species was popular
amongst most small scale and commercial farmers in
Zambia. However, despite being a good species for
aquaculture,
O. niloticus
was withdrawn from small
scale aquaculture in Zambia (Simataa and Musuka,
2012).
Since the experiment was conducted in experimental
ponds made of concrete sides, growth and survival
rate of the fish was expected to be influenced by feed
fed only, not from natural sources. The feed was also
expected to increase growth and survival rate of the
fish since they were all nutritionally balanced feeds.
Study site
The study was carried out in 2m × 4m Hapas mounted
in a 30m × 50m pond at the National aquaculture
research and development centre (NARDC) in Kitwe
for twelve (12) weeks to allow for more data to be
collected to ascertain whether there were any
statistical differences among the different feeds.
Figure 1: Showing the study area (Source: NARDC)
Experimental setup and design
This experiment was a single factor in a completely
randomized design (CRD), with three treatments. A
total of 90
O. niloticus
fingerlings with a stocking rate
of 15 fish (i.e. with an average initial body weight of
10.5 ± 0.57g and length of 35.5cm/fish) per hapa were
used, replicated two times. The fingerlings’ were
sourced from an earthen pond within the farm and
acclimatized in a tank for two weeks. Thereafter,
fingerlings were randomly selected from the
acclimatization tank, weighed and measured before
stocking in hapas. Prior to the commencement of the
experiment, fish was conditioned to the rearing
environment for 48hrs without feeding.
Water source and water quality
The source of water for NARDC fish farm was
Mwekera Dam, which was readily available
throughout the year (perennial). Water in the
experimental pond was maintained at constant level
with the same condition throughout the period. Water
quality parameters such as: dissolved oxygen, pH and
temperature were measured twice per week using a
Diometer kit to maintain a stable environmental
condition.
On-farm aquafeed (Diet 1) formulation
The ingredients of the diet, which were purchased
from the markets within Kitwe, comprised: fish meal,
soybean meal, maize bran, vegetable oil, vitamin and
mineral premixes, while cassava meal was used as
binder. Fish and soybean meals being major protein
sources in fish and shell-fish diets,
were
proportionally included as required (Olvera – Novoa
et al., 1990; Refstic et al., 1999).
The diet with 30% crude protein (CP) was formulated,
using Pearson’s square method to contain essential
nutrients to meet the nutritional needs of the fish as
required in any culture system to improve growth rate
with higher protein content as described by Barrows
and Hardy (Barrows and Hardy, 2001).
Diet preparation
On-farm aqua feed was prepared following the
procedure outlined by Lovell (Lovell, 1998). It was
prepared by first mixing the dry macro-ingredients; of
fish meal, soybean meal, rice bran and maize bran,
before adding oil. Vegetable oil was included in the
diets at 1% for all diets to provide n-6 fatty acids
(Lovell, 1998). Micro-ingredients, mineral and
vitamin premixes were added each at 1.5% to the
macro ingredients and thoroughly mixed. Lysine and
DCP inclusion rate was at 100g each. Cassava meal
