Mannanoligosaccharides as a Carbon Source in Biofloc Boost Dietary Plant Protein and Water Quality, Growth, Immunity and <i>Aeromonas hydrophila</i> Resistance in Nile Tilapia (<i>Oreochromis niloticus</i>)
Asmaa T.Y. Kishawy,
Alaa H. Sewid,
Hend S. Nada,
Mohamed A. Kamel,
Shefaa A.M. El-Mandrawy,
Taghrid M.N. Abdelhakim,
Abd Elhakeem I. El-Murr,
Nihal El Nahhas,
Wael N. Hozzein,
Doaa Ibrahim
Affiliations
Asmaa T.Y. Kishawy
Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
Alaa H. Sewid
Departments of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
Hend S. Nada
Departments of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
Mohamed A. Kamel
Department of Pharmacology, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
Shefaa A.M. El-Mandrawy
Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
Taghrid M.N. Abdelhakim
Department of Fish Health and Management, Central Laboratory for Aquaculture Research, Agriculture Research Center, Abo Hammad 44519, Egypt
Abd Elhakeem I. El-Murr
Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
Nihal El Nahhas
Department of Botany and Microbiology, Faculty of Science, Alexandria University, Moharram baik, Alexandria 21515, Egypt
Wael N. Hozzein
Bioproducts Research Chair, Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
Doaa Ibrahim
Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, Al Sharqia Governorate 44519, Egypt
The aim of the present study was to evaluate mannan oligosaccharides (MOS) or glycerol (GLY) as a carbon source on biofloc systems of Nile tilapia (O. niloticus) juveniles. Fish (n = 750) were reared in open flow (Controls) or biofloc systems (B-GLY and B-MOS) fed with a plant or fish protein source over a period of twelve weeks. Total ammonia nitrogen and nitrate decreased in the biofloc groups, while biofloc volume increased in B-MOS. Compared to the controls, B-MOS and B-GLY exhibited higher weight gain and improved feed conversion, irrespectively of the diet. Serum level of C-reactive protein was reduced, while IgM and lysozyme activity was higher in the B-MOS fish, compared to other groups. Intestinal Bacillus spp. count was increased, whereas Vibrio, Aeromonas and Pseudomonas spp. counts decreased in B-MOS reared groups, compared to the other groups. The proinflammatory cytokine (IL-8 and IFN-γ) transcript expression was upregulated in B-MOS more than B-GLY reared groups. Compared to the controls, the virulence of Aeromonas hydrophila was decreased in the B-MOS and B-GLY groups. The results indicate several benefits of using MOS as a carbon source in a biofloc Nile tilapia system; a cost benefit analysis is required to assess the economic viability of this.
