Growth performance, feed utilization and gut histology of monosex Nile tilapia (Oreochromis niloticus) fed with varying levels of pomegranate (Punica granatum) peel residues

• Published in: Aquaculture, Aquarium, Conservation & Legislation Vol. 12; no. 1; pp. 298 - 309
• Main Authors: Toutou, Mohamed M, Osman, A laa G M, Farrag, Mahmoud M S, Badrey, Ahmed E A, Moustafa, Mohsen A
• Format: Journal Article
• Language: English
• Published: Cluj-Napoca Bioflux SRL 01.02.2019
• Subjects: Antioxidants; Aquaculture; Aquaria; Aquariums; Bioactive compounds; Biology; Body composition; Body weight; Body weight gain; Diet; Digestive system; Economics; Energy utilization; Feed composition; Feeds; Fingerlings; Fish; Fish feeds; Fishing; Flavonoids; Food; Food industry; Food processing industry; Freshwater fishes; Goblet cells; Growth rate; Histology; Industrial wastes; Liver; Oreochromis niloticus; Proteins; Residues; Seeds; Survival; Tilapia; Trout; Utilization; Weight gain; Wound healing; Egypt
• ISSN: 1844-8143; 1844-9166

A large quantity of pomegranate peel (PP) residues is produced in juice manufacturing, representing a valuable waste of the food industry as they contain bioactive compounds. A study was conducted to investigate the appropriate levels of PP residues in the diet of monosex Nile tilapia (Oreochromis niloticus) to improve survival, growth performance, feed utilization, whole body composition and gut histology. Monosex O. niloticus (7.0 g) were tested with eight levels of PP: 0, 1, 2, 3, 5, 10, 15, and 20%. Fish were stocked in aquaria (100x40x50 cm), at a density of 15 fingerlings per group and fed on a pelleted diet (~25% crude protein, CP), 3 times daily for 90 days. Fish quality in terms of whole body composition showed the best level at 5% PP and the lowest at 20% PP level. The results of the present work revealed that body weight, weight gain and specific growth rate for the fish fed diets contained lower different levels of PP were non-significantly reduced (p > 0.05) compared to the control group. Based on the obtained results, the fish fed on 5% and 3% PP levels exhibited the best performance and the best feed utilization indices. This was evidenced by the best protein efficiency ratio and the highest energy utilization for those fish. This was supported also by the increase in the length of villi and the number of goblet cells of monosex O. niloticus fed on 3 or/and 5% level PP. It is recommended to add the PP to the diets of monosex O. niloticus up to 5% to enhance body composition of fish, feed utilization and fish integrity with increasing economic efficiency.