Effects of Reduced Rations on the Growth and Food Conversion Efficiency of the Silver Sea Bream, Sparus sarba

Abstract

The effects of reduced rations on the growth rate and the efficiency of food utilization of four-month-old silver sea bream Sparus sarba were examined, at ambient water temperature. The relationship between growth rate (g) and food intake (f) was expressed by the equation g=-0.3122+1.6006f-0.2384f². The optimum ration was estimated to be 1.15 % wet body weight/day and it was equivalent to 41.4 % of the ration sufficient to satiate the fish in one continuous feeding. The maintenance requirement was calculated to be 0.201 % wet body weight/day. Gross conversion efficiency increased rapidly with increasing ration up to a maximum at the optimum ration, and declined at higher rations. Net conversion efficiency was highest at near maintenance ration and declined with increasing the ration size. The relationship between net conversion efficiency (En) and food intake (f) was expressed by the equation En=1.5505-0.2371f.