Turkish Journal of Veterinary and Animal Sciences

Abstract: Growth performances, daily food consumption and feed conversion ratios of rainbow (Onchorynchus mykiss) and brook trout (Salvelinus fontinalis) reared as single and mixed species were compared. During the experimental period, which lasted for about a growing season (December - June, 217 days), mean % weight increment of single species brook trout group were maximum (from 18.2 to 165.6 g), followed by mixed rainbow (26.8 to 241.6 g) and brook trout (17.0 to 151.8 g), and single species rainbow trout (27.5 to 207.6 g). Rates of increment in biomass were in similar order. Final mean weights of single species brook trout appeared to be higher than those of mixed ones, while it was other way around in rainbow trout groups (P<0.05). There were no significant differences in daily food consumption and feed conversion ratios between groups, although feed conversion ratios of rainbow trout seemed to be slightly higher than those of brook trout. In general, daily food consumption and feed conversion ratios, growth rates and condition factor values increased with water temperature.

Key Words: Rainbow trout, Oncorhynchus mykiss, Brook trout, Salvelinus fontinalis, Polyculture, Growth, Food Consumption, Feed Conversion Ratio