Replacement of fish meal in diets for Australian silver perch, Bidyanus bidyanus V. Least-cost formulation of practical diets

Ž . y1 Silver perch fingerlings 80.7"1.2 g were stocked at a density of 15,000 fish ha in earthen Ž . y1 ponds 0.1 ha and cultured for six months to a market size of )350 g fish . Fish were fed a Ž . reference diet SP35; 27% fish meal or one of two test diets formulated using a least-cost linear feed formulation program and digestibility coefficients for a range of Australian agricultural Ž . Ž . Ž . products meat meal and plant proteins . In the test diets, all but 5% 95LC2 or 10% 95LC1 of Ž . the fish meal was replaced. Survival was high )95% in all ponds. There was no significant difference between the performance of silver perch fed the two test diets. The mean weights Ž . Ž y1. Ž . 431.9 g and 439.8 g , daily growth rates 2.5 g fish and FCRs 2.0 and 1.9 of fish fed 95LC1 Ž . Ž . and 95LC2, respectively, were significantly different P-0.05 from the weight 395.4 g , daily Ž y1 y1. Ž . growth 2.2 fish day and FCR 2.2 of fish fed SP35. The diet ingredient cost to produce 1 kg fish was significantly lower for 95LC2 than the costs of the other diets AUD$:1.06 vs. 1.52; Ž . P-0.05. Diet did not significantly affect body composition nitrogen, fat, ash or energy or sensory quality of the fish. These results show that least-cost diets containing meat meal and plant Ž . proteins as replacements for all but 5% fish meal are suitable for silver perch grown to market size in earthen ponds. q 2000 Elsevier Science B.V. All rights reserved.