Curcuma longa and Allium sativum as health promoters in genetically improved farmed Tilapia (GIFT) - A green drug approach in hi-tech aquaculture using biofloc

Abstract

In biofloc-based fish farming, the pathogen Aeromonas hydrophila poses substantial financial risks, while chemotherapeutics in such a system can disrupt delicate microbial balance and promote antimicrobial resistance. Hence, our study aims to evaluate the impact of dietary supplementation of Curcuma longa (turmeric) and Allium sativum (garlic) extracts on the health of Genetically Improved Farmed Tilapia (GIFT) in the biofloc system. Initially, in a 45-day feeding trial followed by 15-day challenge study, four experimental diets with varying turmeric (TE) and garlic extract (GE) doses (T1: 0.05% TE, T2: 0.1% TE, T3: 0.05% GE, T4: 0.1% GE) were tested against a control group as a prophylactic measure. The basal diet for the control group was devoid of herbal extract. The health of botanicals-fed groups in terms of growth performance (percentage weight gain, protein efficiency ratio, feed conversion ratio, and specific growth rate) and immune response (haematological parameters, total serum protein, albumin, globulin, oxidative burst activity, myeloperoxidase activity, and total Immunoglobulin) was significantly (p < 0.05) improved compared to control. The T2 and T4 groups, which received a higher dose of herbal extract (0.1%), demonstrated better relative percent survival (RPS) at 40% and 35%, respectively, after the challenge. In a subsequent 30-day challenge study, to evaluate the therapeutic efficacy of turmeric and garlic extracts, three diets were prepared with different ratios of turmeric and garlic extract (T1: 75:25, T2: 50:50, T3: 25:75) at a maximum dosage of 0.1% herbal inclusion based on the finding of the first experiment. The T1 group showed the highest RPS at 54%, followed by T2 (42%) and T3 (35%). Overall, the present study suggests that dietary supplementation of 0.1% turmeric and garlic extracts separately as a prophylactic measure and a 0.1% mixed herbal supplementation at a 75:25 ratio (turmeric to garlic) as a therapeutic measure may effectively control A. hydrophila infection in GIFT farming using biofloc.