Assessment of dietary mannaoligosaccharides and β-glucan on the growth, somatic indices and haematological parameters of African catfish (Clarias gariepinus)

The effects of dietary mannaoligosaccharides (MOS) and β-glucan on the production performance of African catfish, Clarias gariepinus, was examined in this study. Three (3) trial diets were produced viz-a-vis., Control (basal diet, BD), MOS (BD + 0.2% MOS) and β-glucan (BD +0.02% β-glucan) and fed to catfish (11.77±0.05 g fish-1) for 63 days. Nine circular tanks were distinctly assigned into 3 dietary groups in triplicate, stocked with 100 fish per tank (85 L), and fed twice daily (8:00 - 9:00h and 17:00 - 18:00h). The results indicated that there was no significant difference (p>0.05) in the mean final body weight, specific growth rates, feed conversion and protein efficiency ratios, and survivals among the various treatments groups. Similarly, somatic indices (condition factors, hepatosomatic indices, and viscerosomatic indices) measured were not significantly different (p>0.05) across the experimental groups. However, the haematological parameters such as packed cell volume, haemoglobin as well as the erythrocyte and leucocyte counts were significantly (p<0.05) lower in the catfish fed MOS diet. It could be concluded herewith that dietary supplementation of MOS and β-glucan do not have a deleterious effect on African catfish production. Further study is however warranted to establish dose-response effect of MOS and β-glucan on innate immunity of African catfish (C. gariepinus).