Dietary garlic (Allium sativum) crude polysaccharides supplementation on growth, haematological parameters, whole body composition and survival at low water pH challenge in African catfish (Clarias gariepinus) juveniles

This work investigated the potential effects of dietary garlic (Allium sativum) crude polysaccharide (GPE) (0, 0.5, 1.0, 2.0, and 4.0%/kg diet) on growth, haematological parameters, whole body composition, and resistance against low pH in African catfish, Clarias gariepinus juveniles. At the end of 60 days, fish fed GPE supplemented diets had significantly increased (P < 0.05) in growth parameters (weight gain, absolute growth rate, specific growth rate, and final weight compared to those fed a control diet. Similarly, feed utilization indices (feed intake, feed conversion ratio, and protein efficiency ratio) were significantly improved (P < 0.05) in GPE supplemented fish compared to the control. Despite haematological indices being somewhat high in GPE supplemented fish, significant increase (P < 0.05) was only observed in the red blood cells (RBC) (for those fed 0.5%, 1.0%, and 2.0%), and in mean corpuscular haemoglobin concentration (MCHC) (for those fed 0.5% and 1.0%). No significant difference (P > 0.05) was observed in the cumulative survival among dietary groups following a challenge with low pH, except somewhat high survival in garlic-supplemented fish especially at 72 h. Similarly, no significant difference (P > 0.05) was presented in the whole body composition and organo-somatic indices among groups. Based on the second order polynomial analysis, dietary inclusion level less than or equal to 1.88% of garlic/kg diet is estimated suitable to support growth, feed utilization, and ultimately health in C. gariepinus juvenile culture. (C) 2019 The Author(s). Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative.