Immunostimulatory Effect of Garlic Powder (Allium sativum) on Growth and Haematological Parameter of Clariid Catfish (Claria gariepinus) Juveniles

Abstract

This study examined the immunostimulatory effects of garlic powder (Allium sativum) on growth performance, haematological parameters, immune response, and disease resistance of African catfish (Clarias gariepinus) juveniles. Garlic powder was incorporated into five experimental diets at inclusion levels of 2, 3, 4, and 5 g/kg, while a garlic-free diet served as the control. The 56-day feeding trial followed a completely randomized design, with 150 juveniles stocked in 10 tanks and fed twice daily at 5% body weight. Growth was monitored bi-weekly, and water quality was assessed weekly.

After the trial, fish were challenged with Aeromonas hydrophila to evaluate disease resistance. Haematological and biochemical parameters were analysed using standard methods. Fish fed 2 g/kg garlic (T1) showed the highest growth performance, while the control recorded the lowest. Haemoglobin, packed cell volume, and red blood cell counts decreased with increasing garlic inclusion, whereas white blood cell counts increased, peaking at 5 g/kg (T4). The lowest mortality rate occurred at 3 g/kg garlic inclusion (T2). Overall, moderate garlic supplementation enhanced growth and disease resistance, while excessive inclusion may impair immune defence.