AUTHOR=Fadel Amr , Metwally Mohamed M. M. , Hassan Habib Ul , Abdelmageed Adel A. , Arai Takaomi , Ahmed Mohammad Z. , Abdel-Aziz Mohamed F. A. 

TITLE=Growth, immunomodulatory, histopathological, and antibacterial effects of phytobiotic-incorporated diets on Oreochromis niloticus in unchanged water

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1473053

DOI=10.3389/fmars.2024.1473053

ISSN=2296-7745

ABSTRACT=Phytobiotics are promising diet alternatives, yet their effectiveness under high-risk aquaculture conditions remains underexplored. Therefore, A 90-day feeding trial was conducted based on dietary supplementation of Nile tilapia Oreochromis niloticus with herbal extracts; Lemon balm Melissa officinalis (MOE), Marjoram Origanum majorana (OME), and Chamomil Matricaria chamomilla (MCE) with 0% water change. The treated groups were compared to untreated groups with herbs or control groups (Positive control (PC: 0% water change) and Negative control NC: (20% as water exchange rate/two days). Fish were cultured at stocking density (20 fish m -3 : 1.8kg of biomass/m3). Together, the physicochemical analysis of the water, clinical responses, growth, and immune responses were evaluated. Furthermore, the herbal-supplemented fish were then challenged with a pathogenic Edwardseilla tarda strain, then mortality was monitored. In the 1 st and 2 nd months, the water parameters were within the permissible limits. After that, a fatally lower dissolved oxygen concentration and the highest levels of ammonia, nitrite, nitrate, and pH were recorded during the 3 rd month. The herbal-treated groups appeared healthy, but during the 3 rd month, lethargy and decreased appetite were evident. Apparent activities of blood and immunoassays were mainly obtained in treated groups and control groups. The herbal-treated groups appeared healthy, but during the 3rd month, lethargy and decreased appetite were evident. Generally, herbal-treated fish showed improved growth performance parameters, survival rates, and resistance against pathogenic bacteria Edwardseilla tarda, particularly in the OME and MOE-treated groups compared to the positive control group. Lastly, phytobiotic supplements have been shown to improve fish stress tolerance, and immune activation for a certain period under stressful conditions or un-exchanged water, basad on the stocking density, dosages of herbs used, and the extent of deterioration of water quality.