Özet:

This study investigated the effects of dietary orange peels (OP) wasting from sweet orange (Citrus sinensis) industry on growth performance, feed utilization, intestinal morphology and proximate body composition of Nile tilapia (Oreochromis niloticus) fingerlings of initial body weight 5.16±0.09 g fish-1 (mean±SE). Fish fed for 60 days on four isonitrogenous (28% crude protein), isocaloric (18.5 MJ kg-1 ) diets supplemented with different levels of orange peel, 0 (CTR), 1 (OP1), 2 (OP2) or 4 (OP4) g kg-1 diet. The results showed that fish fed on OP-based diets had the best weight gain (WG), final weight (FW), specific growth rate (SGR) and feed conversion ratio (FCR) with an optimum level of OP at 2 g kg-1 diet (P≤0.05). CTR treatment produced the poorest growth performance and feed utilization parameters (P≤0.05). Height of villi of the anterior intestine progressively increased as the OP level increased in the diets. This suggested that dietary OP could improve the nutrient absorptive ability of the intestine in Nile tilapia. This finding suggests that dietary orange peel can act as a growth promoter for Nile tilapia fingerlings with an optimum level at 2 g kg-1 diet.

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