EFFECT OF REPLACING DIETARY FISH OIL WITH DIFFERENT PLANT OILS ON GROWTH PERFORMANCE OF NILE TILAPIA, OREOCHROMIS NILOTICUS (L.)
Nader E. El-Tawil*, Mohammad H. Ahmad,
Talaat N. Amer and Medhat E.A. Seden.
Department of Fish Nutrition, Central Laboratory for Aquaculture Research CLAR, Agriculture Research Center, Egypt.
*Corresponding author e-mail: [email protected]
|Received 8/ 6/ 2014||
Accepted 1/ 7/ 2014
This experiment was carried out to study the effect of replacing dietary fish oil by different plant oils on growth performance, feed utilization of Nile tilapia (Oreochromis niloticus) with initial body weight 1.2 ± 0.02 g. Seven isocaloric diets (4.35 kcal/g diet) containing 30% crude protein, with different sources of dietary oils. Each diet was fed in triplicate groups two times a day for 10 weeks. Treatments were: fish oil, FO; linseed oil, LO, corn oil, CO; soya oil, SO; mixture of (50% LO, 25% CO and 25% SO), ML; mixture of (50% CO, 25% LO and 25% SO), MC and mixture of (50% SO, 25% LO and 25% CO), MS. Fish fed diet containing FO or ML were significantly higher (P<0.05) in growth performance values than fish fed on other diets. Survival rate did not differ significantly among treatments. Values of feed conversion ratio FCR and feed utilization parameters were improved significantly at fish maintained at FO and ML diets compared to other treatments. No significant differences were observed in fish body moisture or protein contents at all treatments; while fish body lipid content differ significantly. These results suggest that fish oil could be replaced by a mixture of plant oils in Nile tilapia diet without any adversely affect on growth performance or feed efficiency ratio. Moreover, it is more economic and sharply reduced the fish feed cost.
Keywords: Nile tilapia, replacement fish oil, oil sources, mixture of plant oils, growth performance, feed utilization.