Feeding frequency influences growth, feed consumption and body composition of juvenile rock bream (Oplegnathus fasciatus)

Abstract

The influence of feeding frequency on growth, feed consumption and body composition of juvenile rock bream (Oplegnathus fasciatus) was investigated for 70 days under an ambient water temperature (mean = 22.1 A degrees C) in sea cages at Tongyeong, in the southern part of Korea. A total of 600 juveniles were used in this experiment, from which 50 juveniles (initial mean body weight 11.6 g) per cage were randomly distributed to 12 cages. They were hand-fed to satiation with a commercial diet (42.5 % protein and 21.2 kJ/g energy) at one of four different feeding frequency trials (one, two, three, and four meals per day) with triplicates. At the end of the experiment, the mean final weight of fish fed one, two, three and four meals per day were 46.3, 54.5, 60.7 and 60.1 g, respectively. The fish fed three and four meals per day showed the highest specific growth and feeding rates. The feed conversion ratio was not significantly (P > 0.05) affected by the feeding frequency. The extent of size variation in weight significantly (P < 0.05) decreased with the increase of feeding frequency. The maximum feed intake of fish appeared at the first meal (08:30) of each treatment. As feeding frequency increased, lipid and energy contents also increased significantly (P < 0.05), but ash content decreased (P < 0.05). The total nitrogen waste output of fish was not significantly (P > 0.05) affected by the feeding frequency. We conclude that the optimum feeding frequency aimed at optimized growth of juvenile rock bream weighing from 10 to 60 g reared in sea cages is three meals per day under our experimental conditions including particular diet and temperature.