EFFECT OF PROBIOTICS ON THE GROWTH AND PRODUCTION PERFORMANCE OF TILAPIA (OREOCHROMIS NILOTICUS) IN NYLON NET CAGES IN FRESHWATER POND
Abstract
The present study was conducted to ascertain the impact of probiotics on the growth and
production of tilapia (Oreochromis niloticus) for 120 days from 15 July to 12 November
2015. There were four treatments such as T1 (super biotic probiotics), T2 (biozyme
probiotics), T3 (zymetin probiotics) and T4 (control) having three replicates of each with a
size of 1.5 m
3
(1.5m x 1m x 1m) each. Pond was cleaned manually and limed @ 250 kg/ha of
CaO. It was then fertilized with urea and TSP @ 25 kg and 37.5 kg/ha, respectively. After
few days of fertilization, 12 cages made of nylon net, nylon twine and bamboo were set up in
the pond. Cages were stocked with nursed male tilapia fry at a density of 35 nos./m
with
average size of 3.0 g. Tilapia of all the cages were fed with Mega floating feed @ 5-10 % of
total biomass at three times daily. Feed was supplemented with probiotics @ 0.5 g/kg of feed.
Water quality conditions such as temperature, transparency, dissolved oxygen, pH, total
alkalinity, nitrate and ammonia were within suitable range for tilapia growth and did not
cause any stress. Growth of tilapia was recorded at fifteen days intervals and feed was
adjusted accordingly. Higher net growth of tilapia was found in T3 (272.78 g) followed by T2
(242.56 g), T1 (222.76 g) and T4 (199.35 g). The lowest food conversion ratio (FCR) was
obtained in T3 (1.01) than that of T4 (1.38), T1 (1.23) and T2 (1.14), respectively. Significantly
(p<0.05) highest gross production (8.82 kg/m
2
) was achieved from T3 compared to T2 (7.78
kg/m
2
2
2
). There was no significant (p>0.05) difference in
production between T1 (7.23 kg/m
), T1 (7.23 kg/m
2
) and T4 (6.35 kg/m
). The highest net profit (Tk.
401.5/m
2
) and T2 (7.78 kg/m
2
2
) and T4 (Tk.
119.0/m
) was found in T3 than that of T2 (Tk. 281.6/m
2
2
), T1 (Tk. 211.6/m
2
). The growth and production of tilapia of this study was very much higher than the
production of tilapia reported from earthen freshwater and brackishwater bodies. Therefore,
from the results of the study it may be concluded that probiotics may be suggested to apply in
aquaculture for boost up fish production and can also contribute to national production to a
significant level.