International Journal of Aquaculture, 2016, Vol.6, No.15, 1
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Cardiosomatic indices for the fish fed the experimental diets ranged from 0.10 ±0.01% to 0.21 ±0.02%. The fish
fed AMX1 (control diet) had the highest and lowest values were from the fish fed AMX2 diet. The fish fed the
control diet had significantly higher (p < 0.05) cardiosomatic index compared to others (Table 5) Hepatosomatic
indices for the fish fed the experimental diets ranged from 0.87 ± 0.19% to 1.81 ± 0.39%. The highest
hepatosomatic index value was from AMX2 diet and the lowest value was from the fish fed control diet. The fish
fed the control diet had significantly lower (p<0.05) hepatosomatic index compared to others, while no significant
difference (p<0.05) existed between fish fed AMX2 and AMX3 diets (Table 5). Renosomatic indices for the fish
fed the experimental diets ranged from 0.21 ±0.02% to 0.49 ±0.01%. The highest value was from fish fed AMX2
diet, while the lowest value was from the fish fed the control diet. The fish fed the control diet has significantly
lower (p<0.05) hepatosomatic index than AMX2, but not significantly different from AMX3 diet (Table 5).
Table 5 Organosomatic indices of
Clarias gariepinus
fed Amoxicillin meal (AMX’S) diets
PARAMETERS
AMX1
AMX2
AMX3
Cardiosomatic index
0.21 ±0.02
a
0.10 ±0.01
b
0.14 ±0.00
b
Hepatosomatic index
0.87 ±0.19
b
1.87 ±0.39
a
1.12 ±0.05
ab
Renosomatic index
0.21 ±0.02
b
0.49 ±0.01
a
0.48 ±0.05
a
Visceral somatic index
2.32 ±0.30
4.58 ±1.28
2.98 ±0.44
Brain somatic index
0.62 ±0.05
a
0.43 ±0.02
b
0.62 ±0.03
a
Fat deposit index
2.73 ±0.23
a
1.20 ±0.58
b
1.20 ±0.39
b
Note: Values with different superscripts in each row are significantly different (P < 0.05)
The histopathological examinations varied with degree of lesions from mild to severe in the various organs of the
fish fed the tested diets as shown in Table 6.
Table 6 Summary of histopathology of the tissues of
Clarias gariepinus
fed Amoxicillin meal (AMX’s) diets and Control diet
Organs
AMX1
AMX2
AMX3
Brain
Extensive multifocal
vacuoles of varying sizes
Marked aggregates of deeply-basophilic cells
within the white matter and degenerate neurons
Liver
NVL
intracellular fatty deposition
intracellular fatty deposition
Kidney
NVL
Shrunken glomerular tufts (mild)
Shrunken glomerular tufts (severe)
Heart
NVL
Moderate thinning of myocardium
Severe thinning of myocardium
Gill
NVL
NVL
NVL
Stomach/Intestine
NVL
Villi atrophy
Gastric villi markedly thinned out
4 Discussions
The feeding trials revealed that
C. gariepinus
responded to all the diets, irrespective of amoxicillin concentrations.
Amoxicillin promoted the growth of
C. gariepinus. C
.
gariepinus
was able to effectively utilize the amoxicillin
for growth. The highest growth performance was observed in the fish fed AMX2 diet, although this was not
significantly different from the fish fed AMX3 diet. This better growth performance in fish fed the antibiotic may
be attributed to the levels of antibiotic in the diet which might have destroyed pathogenic organisms in the
alimentary canal, thus reducing morbidity and mortality due to reduced sub - clinical diseases by Rosen (1995).
Furthermore, the use of antibiotics have been reported to enhance digestibility by preventing the irritation of the
intestinal lining and effective utilization of the nutrients from the intestine by thinning of the mucosal layer, which
led to improve animal performance and increased economic output (Dafwang et al., 1987; Ewing and Cole, 1994;
FAO, 2005). The results from the present study agree with Shalaby et al.
(2006) that there were no significant
differences in the final weight gains among the fish fed chloramphenicol at 15, 30 and 45 mg/kg diets. Similar
results have been obtained by Lawal et al. (2012) and Adewole (2016) that reported similar higher growth rate
than the control in
C. gariepinus
fed varying levels of oxytetracycline and furasol as dietary additives.
The feed intake increased with increasing levels of AMX’s diets, but it was not significantly different among the
treated groups but significantly differed from the control. This indicates that the
C. gariepinus
was able to accept
