DIETARY ORANGE PEEL AS A GROWTH PROMOTER FOR NILE TILAPIA Oreochromis niloticus

Mohamed El-S. Salem and Heba M. Abdel Ghany
National Institute of Oceanography and Fisheries (NIOF),
Alexandria, Egypt
Salem_200080@yahoo.com
 

Sweet orange (Citrus sinensis) is a plant member of the Citrus family and principally cultivated in subtropical regions. Citrus mainly used regularly for juice and jam production which bring huge amount of by-product, such as peels. The peels contain a considerable concentration of ascorbic acid much more than the juice, and that the peel additionally contain higher concentrations of active materials. Many studies revealed the positive role of herbs that contain different bioactive components which may affect digestive processes in a positive way by enhancing enzyme activity, improving digestibility of nutrients and food absorption, consequently resulting in enhancing of fish growth.

There are no studies concerning the effects of orange peels on fish particularly as feed additives to promote the growth.  Therefore, the aim of the present study was to assess the sweet Citrus peels in terms of growth induction of Nile tilapia fingerlings.

Fish were divided into 4 groups and fed for 60 days with four experimental diets (3 supplemented diets with 1 gkg-1diet (OP1), 2 g kg-1diet (OP2) or 4 g kg-1diet (OP4) of orange peel and a control group). At the end of the experiment, the main growth, feed utilization parameters and proximate body composition were investigated.

The results showed that weight gain (WG%) of fish fed on OP1 and OP2 diets was significantly higher than those fed on other diets (P≤0.05) (table 1). Moreover, Feed conversion ratio (FCR) was also affected by the feed additive, where FCR in fish fed the orange peel supplemented diets was lower than in fish fed control diet (table 2). It could be concluded that OP can efficiently act as a growth promoter for Nile tilapia fingerlings to a certain limit.