Effect of different levels of lysine and threonine on carcass characteristics, intestinal microflora and growth performance of broiler chicks

Abstract

The aim of current study was to evaluate the effect of different levels of lysine and threonine on performance, carcass characteristics and intestinal microflora of broiler. Nine hundred and sixty Ross 308 one-day-old female broiler chicks were selected, and they were randomly divided in a factorial design with 12 treatments, four replicates and 20 chicks in each replicate. The tested diets included four levels of lysine (100, 110, 120 and 130%, suggested by NRC) and three levels of threonine (100, 110 and 120%, suggested by NRC). Two phase (starter 0–21d; finisher 22–42 d) feeding schedule was followed. Results showed that of 21 days of age, 120% of lysine and threonine the live and carcass weights and breast, thigh and liver yields in chicks increased (p