Effects of feeding level and frequency on growth and food conversion ratio of juvenile silver perch (Bidyanus bidyanus)

Abstract

Proc. Aust. Soc. Anim. Prod. 1996 Vol. 21 EFFECTS OF FEEDING LEVEL AND FREQUENCY ON GROWTH AND FOOD CONVERSION RATIO OF JUVENILE SILVER PERCH (BIDYANUS BIDYANUS) A.J. RUSSELLA, S.J. ROWLANDB and N.P. McMENIMAN A * Dept Farm Animal Medicine and Production, The University of Queensland, St. Lucia, Qld 4072 B NSW Fisheries, Grafton Research Centre, Grafton, N.S.W. 2460 Silver perch (Bidyanus bidyanus) is a species of native freshwater fish that has been identified as having a potential for aquaculture (Rowland et al. 1995). Growth rate and efficiency of feed utilisation are important determinants of productivity in aquaculture systems. Our experiment examined the influence of level of feeding and frequency of feeding on the growth and food conversion ratio (FCR) of juvenile silver perch. One hundred and eighty fish with a mean body weight of 1.3 + 0.14 g were randomly allocated to 18, 70 L tanks (10 fish/tank). The aerated water in the tanks was saline (5 g/L). Water temperature was maintained in the range 24.9 - 26.2OC and the water in each tank was replaced every 7 days. The fish were fed a diet based on fishmeal, soybean meal, wheat and sorghum, that contained 35.6% crude protein (Allan and Rowland 1992). This diet was fed at either 5% or 10% of body weight and at feeding frequencies of 2,4 or 6 times per day. The 6 treatments were replicated 3 times. The experiment was continued for 4 weeks. The fish were weighed every 7 days and feed input was measured. These results indicate that the feeding level required to obtain maximum growth rate of silver perch juveniles lies between 5% and 10% of their body weight; feeding at the 10% level resulted in an increase in FCR which suggests that this level exceeded their ad Zibitum intake and some food was wasted. ALLAN, G.L. and ROWLAND, S.J. (1992) Amt. Aqua. 6: 39-40. ROWLAND, S.J., ALLAN, G.L., HOLLIS, M. and PONTIFEX, T. (1995). Aqua. 130: 3 17-28. 370