This experiment was designed to study the main effect of stocking size and stocking density
levels and their interactions on growth performance, feed utilization, proximate chemical
analysis of whole-body fish, some biochemical, hematological parameters, and liver
function, of Nile tilapia (Oreochromis niloticus) fingerlings. All stocked fingerlings in
enclosures (hapas) were cultured for 84 days. A (2 × 3) factorial design involved a total of
240 fingerlings of two different stocking sizes – beginning weight (5.94±0.70g and
20.90±0.91g) that were stocked at three different stocking densities (5, 10 and 15 fish/m3
),
respectively in twelve enclosures (hapas 1×2×1 m - 2m3
) (duplicated for each). At the end
of this experiment, the results indicated that final BW, (WG, ADG, SGR, RGR) and feed
utilization (FCR and PER) of fish increased with increasing stocking size. The stocking size
20.90 gm (W2) released the highest significantly (P<0.05) BW compared with the stocking
size 5.94 gm (W1) fish groups. The final BW of O. niloticus increased with the decrease of
stocking density levels, thus fish at stocking density 5 fish/m3
(S1) showed the highest BW
compared to the other two fish groups 10 and 15 fish/m3
. With regard to the effect of
interaction between stocking size and stocking density on final BW, the highest final BW
was recorded by fish (T4) while the lowest one was shown by fish in (T3). Chemical
composition, RBCs, WBC, Hb, Tch ALT, and AST of O. niloticus were not affected by the
two stocking sizes 5.94 and 20.90 g and the differences between the two groups were not
significant While, these measurements were affected by stocking density levels (P>0.05).