Feed efficiency of diets with different energy and protein concentrations supplemented with methionine in laying quails

Abstract

The study was conducted to evaluate the feed efficiency of quail diets containing different concentrations of metabolizable energy (ME) and crude protein (CP) with constant ratio and supplemented with methionine. Four hundred laying quails (Coturnix coturnix japonica) were randomly assigned to four experimental diets in a 2×2 factorial arrangement. Each dietary treatment used 5 replicates of 20 quails. Two basal diets were formulated to contain 2,800 kcal kg-1 ME and 18.7% CP (High ME-CP) and 2,600 kcal kg-1 ME and 17.3% CP (Low ME-CP). Each basal diet was supplemented with 0 and 0.12% methionine. The High ME-CP diets generated lower feed consumption but higher egg mass and feed efficiency (P<0.01) compared with the Low ME-CP. Furthermore, supplementation of methionine increased egg mass, feed efficiency, energy efficiency ratio and protein efficiency ratio (P<0.01). The High ME-CP supplemented with methionine resulted the highest feed efficiency followed by the Low ME-CP supplemented with methionine, while both High ME-CP and Low ME-CP without methionine supplementation resulted the lowest feed efficiency (P<0.05). In addition, ME and CP consumption of the birds were not influenced by the treatments. Thus, feeding High ME-CP supplemented with 0.12% methionine provided benefit to improve the feed efficiency in laying quails.