Dietary supplementation with miswak (Salvadora persica) improves the health status of Nile tilapia and protects against Aeromonas hydrophila infection

Abstract

Abstract The potential effect of Salvadora persica dietary supplementation on Nile tilapia (Oreochromis niloticus) health was investigated. Four diets were formulated to contain 0 (control), 0.5, 1 and 2 % (w/w) S. persica powder. Fish were fed for eight weeks (pre-challenge period), then challenged with A. hydrophila for seven days (post-challenge period). Results showed that the immune and biochemical parameters besides, white blood cell counts (WBCs), increased significantly at 1 % and 2 % or both levels of S. persica in the pre- and post-challenge period. Most of the hematological indices were elevated pre- and post-challenge at 1 % and 2 % or both S. persica groups compared to other groups. Malondialdehyde (MDA) exhibited a significant decrease with 2 % S. persica diet in pre-challenge and at 1 and 2 % in the post-challenge period compared to the control. Additionally, antioxidant enzyme activities revealed a significant increase in pre- and post-challenge groups, principally in fish fed 2 % S. persica. Furthermore, the highest relative percentage survival, 90 % was recorded in 2 % S. persica. The findings suggested that dietary supplementation of miswak improved hematoimmunological parameters and enhanced antioxidant responses of cultured Nile tilapia and confer protection against A. hydrophila infection.