The objective of this work was to evaluate the relationships of methionine plus cystine with lysine for Japanese quails in the laying phase. Thus, it was used 480 birds at initial age of 65 days, distributed in randomized block design with 6 treatments, 10 replicates and 8 birds per experimental unit. The treatments consisted of basal diet deficient in methionine plus cystine (0.65%), with 19.6% of crude protein and 2800 kcal of metabolizable energy/kg of ration, supplemented with six levels of DL-methionine 98% (0.116; 0.167; 0.218; 0.269; 0.320 and 0.371%), corresponding to methionine plus cystine with lysine ratio of 0.65, 0.70, 0.75, 0.80, 0.85 and 0.90, and the digestible lysine set at a suboptimal level of 1.00. The parameters studied were: feed... |