International Journal of Aquaculture, 2016, Vol.6, No.15, 1
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2
been a common practice for more than 30 years and it is estimated to constitute more than half of the total anti-
microbial drugs used worldwide Ereke et al. (2015).
Antimicrobial drugs have the potential to positively affect growth of animals through better appetite, improved
feed conversion, stimulation of immune system and increased vitality and regulation of the intestinal microflora.
Furthermore, antimicrobial growth promoters (AGPs) in animal nutrition have been of beneficial effect in
improving growth performance and prevention of diseases (Barton, 2000; Snel
et al
, 2002; Adewole, 2016).
Recently, several antibiotics have been used indiscriminately due to accelerated growth of aquaculture in Nigeria,
while several researches have been done to evaluate the appropriate inclusion levels of some common antibiotics
used in fish production. However, in a separate study, Adewole (2016) evaluated the growth rate of catfish
Clarias gariepinus
to different inclusion levels of oxytetracycline, while Lawal et al. (2012) determined the
inclusion levels of oxytetracycline and furasol as antibiotics, respectively. But, there is dearth of information on
the inclusion levels of amoxicillin in the diet of
Clarias gariepinus
in Ibadan, Nigeria. This study, therefore,
sought to evaluate the effect of different doses of amoxicillin on the growth performance, haematology,
organosomatic indices and histopathology of
Clarias gariepinus.
2 Materials and Methods
Study Area
: The experiment was carried out in the Department of Aquaculture and Fisheries Management,
University of Ibadan, Ibadan, Nigeria.
Formulation and preparation of experimental diets:
The experimental diets were formulated using algebraic
method according to Falayi (2003) as shown in Table 1. The diets were prepared with amoxicillin at the inclusion
levels of (0.00%) AMX1 (control without antibiotic), (0.10%) AMX2 and (0.5%) AMX3 based on the reported
dosages of antibiotics by Crevadi et al. (1987). After the formulation, the different ingredients were weighed using
the electric sensitive weighing balance (OHAUS-LS 200 Model). The dough made after was pelleted, sun dried,
packed in tight plastic bags, labeled accordingly and stored at room temperature in the laboratory until its ready
for use as reported by Adewole (2016). Different batches of the feed were prepared every month throughout the
duration of the experiment as recommended by (Sogbesan, 2007).
Table 1 Percentage composition of ingredients (g/100 g diets) in Amoxicillin meal diets for feeding trial
Ingredients
AMX1(Control)
AMX2
AMX3
Fishmeal
28.55
28.55
28.55
Soybean meal
20.93
20.93
20.93
Groundnut cake
20.71
20.71
20.71
Yellow maize
20.76
20.66
20.26
Vegetable oil
2.50
2.50
2.50
Vitamin/mineral premix
1.50
1.50
1.50
Cassava starch (binder)
1.50
1.50
1.50
Common salt
0.50
0.50
0.50
Bone meal
1.00
1.00
1.00
Carboxyl/methylcellulose
2.00
2.00
2.00
Chromic oxide
0.05
0.05
0.05
Amoxicillin
0.00
0.10
0.50
Total
100
100
100
Calculated crude protein
40.00
40.00
40.00
Note: AMX =Amoxicillin
Stocking of experimental fish and Experimental design:
The healthy juvenile of
Clarias gariepinus
(n=20,
mean weight 10.94 ±0.01 g were randomly sorted, weighed and stocked into the experimental tanks in triplicates
using a completely randomized design as reported earlier by Adewole (2016), after been acclimatized for 2 weeks
and the fish were feed at 5% body weight twice daily at 8.00 and 17.00 hours for 84 days.
