الفهرس 
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Abstract
The present study was designed to investigate I) the effect of repeating cycles of feed deprivation and re-feeding on behavior and growth performance of Nile tilapia, II) the effect of feeding frequency on behavior and growth performance of Nile tilapia. First experiment fish (n= 60) classified into three groups (n=10/group, 2 replicates). During the period of the experiment, the control group (C) was fed to satiation three times a day. The feeding regimes of the other two groups were designed as follows (R1): 4 days starvation / 16 days satiation (4 cycles) and (R2): 8 days starvation / 32 days satiation (2 cycles). After 12 weeks, only group R1 demonstrated complete compensatory growth while R2 demonstrated partial compensatory growth. Results demonstrated that feed restriction significantly increased foraging, resting, and chafing behaviors but decreased eliminative behavior. Additionally, feed restriction did not affect on aggressive behaviors. Water quality parameters were improved by increasing dissolved oxygen and pH in restricted fish. Second experiment fish (n= 60) classified into three groups (n=10/group, 2 replicates). 1st twice/day (T1), 2nd three /day (T2) and 3rd four/day (T3). After 10 weeks, Growth data indicated that, the overall body weights of fish fed three and four times daily higher than overall body weight of fish fed two times daily. Weight gain and SGR values of second group were significantly higher than those of the other groups (P<0.01). The best feed conversion ratio was recorded in fish fed 3 times daily. Results demonstrated that, feeding frequency significantly increased foraging in the fish fed 2 times daily. Resting, chafing and eliminative behaviors increased in the fish fed 3 and 4 times daily but feeding frequency not affected on aggressive behaviors. Additionally, feeding fish twice a day increase water pH than fish fed three and four times daily. However, turbidity of water of fish fed four times was significantly higher than turbidity of water of fish fed two times. It was concluded that feeding schedules involving starvation (4F:16R) and re-feeding cycles a promising feed management tool for Nile tilapia culture. Adding, fish which fed 3times daily gave maximum growth and improved the welfare of fish.