Potential use of triticale in diets for rainbow trout: effects of dietary levels and incidence of cooking

Abstract

It is recognized that an increase in digestible energy (DE) can improve the growth performance and protein retention efficiency in rainbow trout. Growth and digestibility trials were conducted to evaluate possible incorporation of triticale (Clercal, a soft wheat x rye hybrid, hexaploid variety) as a potential source of DE for rainbow trout. Four diets were formulated with graded levels of native triticale (0-30% of dry matter) and 2 others with pre-cooked triticale at 20 and 30% of DM. All diets were isoproteic (crude protein: 43% DM) and isoenergetic (gross energy: 20 kJ/g DM). Digestibility of dry matter, starch and energy was affected by both level and nature of triticale. Cooking (15 5 min, 110 °C) improved nutrient digestibilities of diets containing triticale. Growth performance and nutrient retention efficiencies were higher in fish fed diets containing precooked triticale than in those receiving equivalent amounts of native triticale. Triticale appears to hold potential value as an ingredient in trout diets provided some pretreatment of the cereal is made to improve starch digestibility.