The ability of high value plant protein concentrates to replace fish meal in diets for rainbow trout depends on their available nutrient composition, cost, and consistency. The aim of this study was to assess the effects of two novel corn fermented protein products (ANDVantageTM 40Y and ANDVantageTM 50Y, The Andersons, Inc.) on growth performance of juvenile rainbow trout.
A 2 x 5 factorial design was applied with test products included at 0, 7.5, 15, 22.5 and 30% diet dry weight replacing dietary fish meal and poultry meal on a digestible protein (DP) basis. All diets were formulated to 42% DP and 18% crude lipid, supplemented with Lys, Met and Thr to targets of 3.8, 1.3 and 2.1%, respectively, and manufactured by cooking extrusion. Diets were randomly assigned to triplicate tanks of rainbow trout (Oncorhynchus mykiss, Troutlodge Inc., Sumner, WA) with a mean initial weight of 38 ± 0.7 g (mean ± SD). Fish were cultured in poly tanks (320 L) at n = 20 fish per tank in a recirculating system with a flow rate of 4-6 L min-1, temperature at 15 °C, and a 13:11 light:dark cycle, and fed twice daily to apparent satiation six days per week for 12 weeks.
Including ANDVantage products at levels above 22.5% decreased g gain fish (P<0.0001). A significant interaction was observed for feed conversion ratio (FCR; P<0.0001) wherein fish fed ANDVantageTM 40Y had significantly higher FCR than fish fed ANDVantageTM 50Y when fed levels above 22.5%
Optimized inclusion levels, determined by regression analysis for combined data or for each ingredient when interactive effects occurred, indicate that inclusion levels for ANDVantage 40Y and ANDVantage 50Y in rainbow trout diets range from 13.2 to 19.8% depending on the performance variable assessed.